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Zoning Commission Packet 2012 06-27-12
United City of Yorkville '`'` 800 Game Farm Road EST. , _ 1836 Yorkville, Illinois 60560 -4 Telephone: 630-553-4350 0� a 2p� Fax: 630-553-7575 AGENDA ZONING COMMISSION MEETING Wednesday, June 27, 2012 7:00 P.M. City Hall Conference Room 800 Game Farm Road 1. Welcome 2. Roll Call 3. Citizen's Comments 4. Approval of May 23, 2012 meeting minutes 5. Old Business: a) Continued review and Commentary of Proposed CDD, Conservation Design District • Chapter 11G: Conservation Design District 6. New Business: a) Chicago Metropolitan Agency for Planning(CMAP) Grant Application for Local Technical Assistance Program 7. Adj ournment 8. Next meeting date: July 25, 2012 ZONING COMMISSION MEETING Wednesday,May 23, 2012 7:00 p.m. Yorkville City Hall Conference Room 800 Game Farm Road, Yorkville, IL 60560 Meeting Called to Order The meeting was called to order at 7:11 p.m. and Mr. Crouch welcomed everyone. Roll Call Roll call was taken. A quorum was established. Committee Members in Attendance: Greg Millen Jeff Baker Phil Haugen Michael Crouch City Officials in Attendance: Krysti Barksdale-Noble, Community Development Director Citizen's Comments There were no guests in attendance. Previous Minutes Mr. Baker moved to accept the April 25, 2012 minutes and Mr. Millen seconded. There were no discussions, corrections or additions so a vote to accept was made, unanimously accepted and the motion was carried. Mr. Crouch then turned the meeting over to Ms.Noble to cover Old Business. Old Business: Ms. Noble re-capped the last meeting by saying they had looked at the chapters 11-A through 11-F. The E-district(Estate District)was the only one that had any revisions. The "Site and Development Standards"was been removed, and the committee is now done with Residential at this time. If the committee wants to, they can always come back and re-visit it. Additional Business: Ms. Noble went on to the `Subdivision Control Ordinance' that was questioned at the last meeting—specifically Commissioner Neyer's questions on paved pedestrian cross-walks in the middle of long blocks (longer than 900 feet) and fences in the paved area. The fences are in the easement and not the actual cross-walk. She had asked Staff of where this may have ever occurred and was told it has never occurred in this Zoning area (sample photo on page 2 of"Zoning Ordinance Update—Old&New Business Items" Memorandum dated May 15, 2012). She then answered his question about the smallest, minimum lot area for residential, detached districts by doing a comparison to surrounding communities (chart also on page 2 of"Zoning Ordinance Update—Old &New Business Items" Memorandum dated May 15, 2012). Ms. Noble then went on to clarify that the `Affordable Housing Act' was established in January, 2004 and was defined in the act as "housing that has a sales price or rental amount within the means of a household that may occupy moderate or low income housing." This is calculated by taking the median income of the area(moderate would be households with a gross income greater than 50%but less than 80% of the median gross; low would be less than 50%). This area's median income, according to the 2010 census, is $82,007.00. New Business: Chapter 11: Conservation Design District (CDD) - This chapter was prepared by the City's Landscape Architect, Laura Shraw, who is also currently serving as the Interim Director of Parks and Recreation. This may address Commissioner Neyer's question about smaller lots. This is an opportunity to design smaller lots without going to a PUD. The payoff is more green space, amenities and infrastructure (outlined in Chapter 10 which is actually going to be Chapter 11). After reviewing the Chapter, Commissioner Baker voiced his concern over the fact that after protecting the open space, it was not available for recreational uses (no fishing; no swimming; no skating; etc.). Ms. Noble said the H.O.A.s set their own convenances and restrictions—the City does not get involved. She said the City can encourage developers to adopt an active open-space concept(ball fields; fishing opportunities; etc.) instead of just the "engineered water retention ponds"to catch the run-off. Mr. Baker is in full support of a Conservation District—if it can actually be enjoyed. Ms. Noble was going to present these suggestions to Engineering and come back to the next meeting with their thoughts. Mr. Baker made a motion to adjourn; Mr. Millen seconded and agreed by all. The next scheduled meeting is Wednesday, June 27 at 7:00 p.m. at Yorkville City Hall in the conference room. The meeting was adjourned at 7:46 p.m. Minutes respectfully submitted by: Bonnie Olsem o car Memorandum EST. 1836 To: Zoning Ordinance Commission pFrom: Krysti J. Barksdale-Noble, Community Development Director �oa 5as +� tl��o Ty `• CC: Bart Olson, City Administrator y<<E 1`►� Date: June 20, 2012 Subject: Zoning Ordinance Update—Old & New Business Items Staff has prepared the attached revised Chapter 11: Residential Districts for the Zoning Commission to review based upon the April 25�h meeting discussion. The proposed revisions and additional information are detailed below: Old Business: Chapter 11G: CDD, Conservation Design District • Proposed new residential zoning chapter meant to address the desired sustainability elements of "green" land design and as well as provide the opportunity for the clustering of smaller lots not permitted in the standard residential zoning districts, without having to go through the PUD approval process. • Additional information regarding best management practices (BMPs) for utilizing conservation, detention and retention areas for more active open space areas. Additional Business: As a follow-up to our previous meeting discussions regarding Section 11-4-8-B of the Subdivision Control Ordinance (Ord. 2004-52) related to paved and fenced pedestrian crosswalks not less than ten(10) feet wide which may be required by the Plan Commission through the center of blocks more than nine hundred(900) feet long, where deemed essential to provide circulation or access to schools, playgrounds, shopping centers, transportation, and other community facilities. Continuous chain-link fencing four(4) feet high will also be required on both sides of the walkway on an easement. ➢ Staff was able to locate an additional example of such a situation where a mid-block walkway was provided in a subdivision in Hampshire, Illinois for access to a nearby park, as illustrated in the photograph below. Although the walkway is partially delineated with a decorative wood split rail-fence,per our City Ordinance, chain-link fencing could occur within the easement along each side of the walk between the adjacent residential homes. New Business: As mentioned at last month's meeting, staff has completed the attached grant application for the Chicago Metropolitan Agency for Planning's (CMAP) Local Technical Assistance program seeking additional staff resources to complete the research and drafting of the remaining chapters of the Zoning Ordinance update. According to CMAP, the application deadline is August 1, 2012, and those communities which projects meet the criteria of supporting the advancement of the GOTO 2040 plan through local planning projects that address issues of transportation, land use, and housing. Chapter Formatted:Bottom: 0.44",Footer distance from edge: 0" Residential Districts ARTICLE G. CDD,CONSERVATION DESIGN DISTRICT SECTION: 11-11G-1: Purpose and Intent 11-11G-2: Permitted and Special Uses 11-11G-3: Dimensional and Bulk Requirements 11-11G4: Maximum Building Height 11-11G-5: Development Standards 11-11G-1:PURPOSE AND INTENT: The purpose of this chapter is to provide for an alternative zoning procedure for conservation design developments that provide value to the community and the environment over the conventional zoning district and which is consistent with the comprehensive plan and intent of the zoning ordinance. Conservation Design Developments (CDD) are intended to encourage the most imaginative and best possible design of building forms and site planning for tracts of land where unitary plans would best adapt to topographic and other natural features of such sites. The Conservation Design Development district purpose is to: A.Conserve undeveloped land for the purpose of protecting primary and secondary conservation areas in contiguous,un-fragmented,commonly managed landscape to; 1. Protect large, intact wildlife habitat areas and connect patches of wildlife habitat to support greater biodiversity, maintain ecosystem processes and allow larger, healthier populations to exist;and 2. Minimize edge conditions and associated colonization by invasive plant species. B.Contribute to the creation of a community wide greenway system for the benefit of present and future residents; C.Protect productive agricultural soils for continued or future agricultural use by conservin areas of land large enough to allow for efficient farming operations through sustainable means�y promoting community gardens as buffers between farmlands and housingl; Comment[KNoblel]:should there be a minimum size such as 200 acres?Or would a sliding D.Encourage innovation and promote flexibility,economy,and ingenuity in development; scale based on overall size be more appropriate? E.Provide for the conservation and maintenance of greenway land and for active or passive recreational use by residents; F. Provide greater efficiency in the siting of services and infrastructure, including the opportunity to reduce length of roads,utility runs,and the impervious cover required for residential development; G. Protect water quality and reduce erosion and sedimentation by retaining existing vegetation and minimizing development on steep slopes; H. Implement land use, open space,and community policies set forth in the United City of Yorkville's Comprehensive Plan. 11-11G-2:PERMITTED AND SPECIAL USES: Refer to Chapter 6 of this Title. 11-11G-3:DIMENSIONAL AND BULK REQUIREMENTS: Conservation Design Subdivisions are expressly exempt from the lot area, lot width,yard area,and lot coverage requirements of the Zoning Ordinance. Lots must be of a size and shape to allow for compliance with applicable building codes and to provide for high-quality living environment for subdivision residents.Lots immediately abutting or within 150 feet of an existing or approved subdivision may be no smaller than 80%of the average lot size within the adjacent subdivision. 11-11G4:MAXIMUM BUILDING HEIGHT: A. One- and Two-Family detached dwellings: Forty feet (40') and not more than 2.5 stories, whichever is less. B. Single Family Attached&Multiple Family dwellings:Eighty feet(80')and not more than six(6) stories,whichever is less. 11-11G-5:DEVELOPMENT STANDARDS: A. Maximum Development Potential 1. Base Density: i. The United City of Yorkville's Comprehensive Plan land use classifications shall be used to determine base densities: Land Use Classification Maximum Base Density (dwelling units per acre) Rural Neighborhood 0.5 Estate Neighborhood 1.5 Suburban Neighborhood 2.0 ii. If the conservation design subdivision is located in more than one land use classification, the maximum number of dwelling units allowed must be determined separately for each portion of the site lying within a different land use classification. Density may be transferred from one portion of the site to another, provided that such transfers do not result in an increase in the number of dwelling units allowed on the overall site. 2. Dwelling Unit Yield Formula(Pre Bonus) i. Determine Base Site Area 1. (Determine Gross Site Area 2. Subtract Right of Way(existing and ultimate) 3. Equals BASE SITE AREA Comment[mathematic:would a simpler to -'� � also include a mathematical equation as an u. Determine Buildable Area example?Such as: 1. BASE SITE AREA 200 Ac(Gross Site Area)—75 Ac(ROW)=125 Ac 2. Subtract Regulated wetlands and wetland buffers (Base Site Area) 3. Equals BUILDABLE AREA Comment[mNobme3]:Ibid. Example: iii. Determine Net Site Area 1. UILDABLE AREA 125 Ac(Base Site Area)—25 Ac(Wetlands)=100 Ac (Buildable Area) 2. Subtract 10%of buildable area for stormwater management 3. Subtract 15%of buildable area for streets 4. Equals NET SITE AREA I Comment[KNoble4]:ibid. iv. Determine Maximum Dwelling Units Example: 1. �4ET SITE AREA 100 Ac(Buildable Area)x 0.10=10 Ac(Stormwater Management) 2. Multiple by land use classification base density 100 Ac(Buildable Area)x 0.15—15 Ac(Streets) 3. Equals Pre Bonus Maximum Dwelling Units Allowed 10 Ac(Stormwater Management)+15 Ac(Streets)_ 3. Density Bonus ` 25A` 100 Ac(Buildable Area)—25 Ac=Net Site Area i. The maximum increase in density shall be limited to twenty(20)percent of the Comment[K Area) ]:mid. permitted density. The following list of incentives may be utilized to reach a Example: density bonus not to exceed twenty(20)percent. 25 Ac(Net site Area)x 1.5 DU/Ac(Estate 1. �nternal trails and open spaces are connected with existing or potential neighborhood)=34.5 DU/Ac Pre-Bonus Maximum multi use trails and open space outside of the development and provide Dwelling Units Allowed access to the public. Open space must be connected to larger greenway systems when technically possible. 3-5% — Comment[KNoble6]:Should we add a 2. The amount of open space provided exceeds the required open space per reduction for sidewalks? section L of the development byte.(10)percent or more. 3-5% Comment[KNoble7]:Reference the"Park 3. Open space within the development is placed into a conservation Development Standards'in Subdivision Control easement with a legally incorporated land conservation organization or Ordinance. donated to a public open space agency. 3-5% 4. Wetland restoration and/or enhancement performed substantially in excess of the U.S.Army Corps of Engineers permit requirements. 3-5% 5. Remnant prairies, savannas, and woodlands are substantially restored prior to the turnover of the property to the Homeowners Association or land conservation organization. Such restoration will consist of the removal of invasive trees, brush, and herbaceous species and the establishment of native herbaceous species. 3-5% 6. Innovative detention/retention basins such as(a)significant use of native vegetation such as prairies and wetlands to retain water,(b)integration of natural land forms, existing soil filtration characteristics, and natural landscaping into the drainage plan, and/or (c) alternatives to detention basins such as stormwater infiltration in naturalized swales,rain gardens, and gently sloped depressional areas. 3-5% B. Open Space Requirements 1. A minimum percentage of land shall be designated as permanent open space dependent upon the United City of Yorkville's Comprehensive Plan land use classification for said property. The open space area shall be including all non-buildable area and a minimum of 20%of the buildable area. Land Use Classification Minimum Open Space based on Base Site Area Rural Neighborhood 60% Estate Neighborhood 50% Suburban Neighborhood 40% 2. Open space must be dedicated or reserved for one or more of the following uses: i. Conservation and protection of areas that potentially pose a significant hazard to people or property (floodplains, wetlands, and lands whose slope and/or soils make them particularly susceptible to subsidence or erosion when disturbed by development activities) ii. Conservation and protection of any identified significant natural areas (stream corridors, woodlands, hedge rows, rare plant communities, important wildlife habitats,etc.)or other environmentally sensitive areas where development might threaten water quality or ecosystems; iii. Provision of active and/or passive outdoor recreation opportunities,including but not limited to,ball fields,playgrounds,tennis courts,swimming pools,basketball courts,golf courses,fishing ponds,shared-use trails,and picnic areas for the use of the general public. Golf courses shall be designed in compatibly with the Audubon Cooperative Sanctuary Program for Golf Courses and shall endeavor to maximize water quality benefits through the following practices: (a) use of reclaimed water, (b) use of native wetland vegetation along ponds, (c) use of landscaping design and plant material that emphasize native species and promote biodiversity,and(d)limited use of pesticides or integrated pest management.) Comment[KNob1e8]:Discussion ideas iv. Pasture and/or agricultural cropland areas. regarding Best Management Practices(BMPs)for multi-use of stormwater detention ponds in parks and open space is provided in supplementary 3. Ownership and Management materials attached with the packet. i. The petitioner must identify the owner of the open space and is responsible for obtaining and filing an official letter of acceptance of the ownership and maintenance responsibilities. A Property Owners' Association may transfer or convey any and all open space to a land conservation agency or similar entity. ii. The designated owner,or if turned over to a land conservation agency or similar entity,is responsible for maintaining the open space and any associate facilities. If a property owner association is the owner, membership in the association is mandatory and automatic for all property owners of the subdivision and their successors. iii. The petitioner must submit a management plan for the open space and all common areas. The management plan must: 1. Allocate responsibility and guidelines for the maintenance and operation of the open space and any associated facilities,including provisions for ongoing maintenance and for long-term capital improvements; 2. Estimate the costs and staffing requirements needed for maintenance, operation, and insurance and outline the means by which necessary funding will be obtained or provided; 3. Provide that any changes to the management plan be approved by City Staff; 4. Provide for the enforcement of the management plan; 5. A budget must be included which lists operations and capital expenses; 6. Thereafter, yearly inspections will be administered by a qualified consultant selected by and paid for by the property owners' association. A copy of said yearly inspection shall be provided to the City. 4. Legal Instrument for Permanent Protection i. The open space must be protected in perpetuity by a binding legal instrument that is recorded with the deed. The legal instrument must be one of the following 1. A permanent conservation easement in favor of either: a. A certified land trust or similar conservation-oriented,non-profit organization with legal authority to accept such easements. b. A governmental entity 2. An open space tract protected by a permanent restrictive covenant for conservation and/or agricultural purposes in favor of a governmental entity;or 3. An equivalent legal tool that provides permanent protection,as approved by the state's attorney. ii. The instrument for permanent protection must include clear restrictions on the use of the open space. These restrictions must include all restrictions contained in this section, all restrictions approved by the City Council, and any further restrictions the applicant chooses to place on the open space. C. Development Evaluation Criteria 1. In evaluating the layout,amount,and location of lots and open space,the United City of Yorkville shall evaluate the extent to which the site plan: i. Protects floodplains,wetlands and steep slopes from clearing,grading,filling or construction; ii. Preserves and maintains mature woodlands,existing fields,pastures,and prairies; iii. Dwellings sited on least prime agricultural soils; iv. Maintains or creates a buffer of native species vegetation of at least 75 feet in depth adjacent to wetlands and surface waters; v. Designs around existing hedgerows and tree lines and minimizes impacts on woodlands, especially those containing many mature trees, significant wildlife habitat,or not degraded by invasive species; A. Protects wildlife habitats and ravines; vii. Leaves scenic views and vistas unblocked, particularly as seen from public thoroughfares; viii. Avoids siting new construction on prominent hilltops or ridges; ix. Includes a pedestrian circulation system designed to assure that pedestrians can walk/bike safely and easily on the site,between properties and activities within the open space system. All footpaths should connect with off-road trails,which in turn should link with potential open space on adjoining undeveloped properties (or with existing open space on adjoining developed properties); x. Provides for contiguous open space. To the greatest extent practicable, open space shall be designed as a single block with logical, straightforward boundaries. t& gAt y` David R. Smith Turn Down the Volume The low impact development with Power water volume from infiltration speaks the loudest. For the past 50 years, detention ponds have been the classic water as well as lost property,fish habitats decline and the solution to stormwater management.These ugly beasts take result is a big eyesore. e on the burden of collecting runoff and pollutants from large Extensive damage has led many stormwater manag- i areas of pervious and impervious surfaces, hold the water and ers to conclude that detention/retention ponds do not drain it from the pond at a rate that represents flow from a adequately reduce additional volumes of water runoff from small storm, sometimes from a one-or two-year rainfall event. urbanized areas. This situation is often aggravated when I If the detention facility infiltrates some water before draining it additional impervious cover increases runoff volumes. downstream, all the better, but infiltration is often not a prima- The excess runoff from these surfaces exceeds the pond ry benefit nor a centerpiece design consideration.Then there capacity, and minor flooding occurs. One more aggravator: are retention ponds, essentially little lakes that hold water per- detention ponds are community liabilities, often requiring 1 manently while housing mosquitoes and whose level rises and fencing (See above photo). then drains with the advent of wet weather. Detention/retention ponds can be an excuse to avoid I Detention and retention ponds have come under reducing runoff volumes.They instead transfer excess iincreased criticism as a means to manage stormwater.They amounts of runoff volume, storing them for a while and then populate many residential and commercial projects and yet shipping them downstream. In contrast, a first priority of low mysteriously,downstream erosion occurs and sometimes impact development is to exploit every opportunity to reduce minor flooding.The erosion mystery is for the most part runoff volumes by infiltrating stormwater on the site before it explained by the increase in the number of times each year a has a chance to leave.The tools to turn down the volume are receiving stream is subject to flows from a one or two-year rain well known with permeable interlocking concrete pavement event,as well as the longer duration of in-stream flows from (PICP) at the top of the list. Other tools include infiltration each storm. Stream banks can only take so much repetition trenches, water harvesting, and to a smaller extent,bioswales of velocity and shear forces from quickly passing water. Once and rain gardens. ` their carrying capacity is stretched,they begin the process of The notion of using infiltration into PICP as an alternative widening, accommodating additional energy and increased to detention gets cast aside by some designers due to the water volumes by eroding their banks.This results in polluted Continued on p. 18 2 Interlocking Concrete Pavement Magazine November 2010 TUm Down the Volume Continued from p.2 presence of clay soils on a site.While clay soils do not pres- Of course the decision lies with the designer to include ent ideal conditions for infiltrating rainfall,they should not be underdrains(perforated drain pipes)to remove water that can- written off as a means to reduce runoff volumes.The classic not be infiltrated within a given time. Generally, clays under cast-off is sometimes expressed in state and municipal storm- P[CP should be drained within 24 to 72 hours to reduce insta- water manuals by limiting the use of permeable pavement to bility due to saturation. Shorter is always better with regard to soils with 0.5 in. (13 mm) per hour infiltration rate, and others stability under vehicular traffic. remind the reader that soils with lower infiltration rates will ICPI offers a software program called Permeable Design require underdrains. Pro(available at www.[CPI.org)that can assist a designer in Turning the volume down requires revisiting judgments balancing water infiltration into the soil subgrade versus out- about what clay soil can or cannot infiltrate. Every site is dif- flow drainage through pipes.The program allows the user to ferent and requires evaluation by an engineer familiar with vary the diameter, spacing,distance from the soil subgrade the local soils. In approaching every site,there are three core and slope of the pipes to regulate the volume and rate of out- questions in hydrologic design for permeable pavement: flow. It is analogous to using an equalizer to adjust volumes of (1)What is the measured infiltration rate of the soil sub- various frequencies on a well-equipped amplifier.The program grade? also enables the user to evaluate various base thicknesses (2) How much water needs to be infiltrated? given various traffic loads and soil strength characterizations. (3) Can the soil subgrade drain the required amount of A key consideration in deciding infiltration rate for design water from (1) in 24 to 72 hours? is applying a safety factor to measured subgrade soil infiltra- The answer to the first question is found by using ASTM tion rates since the rate of sedimentation of the soil's surface test methods, better known as double-ring infiltrometer tests. is difficult to predict. ICPI recommends using a safety factor of The answer to the second question depends on the site and 2. That means if the on-site measured soil subgrade infiltration what the local municipality requires.After answering the first rate is 0.4 in./hour(3 x 10' m/sec)then the designer should two,the answer to the third question can be found in the table use 0.2 in./hour(1 x 10.6 nn/sec) for drainage calculations. below. It explains the relationship between soil subgrade infil- There are some state stormwater guidance documents that tration and the depth of water that can be infiltrated given 24, tie volume reduction by using permeable pavements to water 48 and 72 hours. The bottom four rows can characterize the quality(pollutant reduction)credits because less polluted range of infiltration rates from some clay soils. water is converted into runoff from a site.This a wonderful rec- The data demonstrates that even low infiltration clay soils ognition of the infiltration-pollutant abatement nexus: less run- can take in an inch (25 mm)or more of water over 24 to 72 off from infiltration means less water pollution.We encourage hours. This can be a sufficient amount to conform to "water all provinces, states and localities to adopt this approach of quality capture volume" required by some states and munici- integrating these two aspects of stormwater design.As turning palities and to the LEED11 Credit 6.2 Stormwater Design- down the volume on an amplifier helps clear the air, reducing Quality Control requirement to capture and treat 90%of the runoff water volume via PICP infiltration helps clear the water.4- average annual rainfall. Soil subgrade infiltration Rainfall depth, in. (mm) Rainfall depth, in. (mm) Rainfall depth, in. (mm) rate, in./hr (m/sec) 24-hour drain time 48-hour drain time 72-hour drain time 0.5 (4 x 101 12 (305) 24 (610) 36 (914) 0.4 (3 x 10.6) 9.6 (244) 19.2 (488) 28.8 (732) 0.3 (2 x 10.6) 7.2 (183) 14.4 (366) 21.6 (549) 0.2 (l x 10-6) 4.8 (123) 9.6 (244) 14.4 (366) 0.1 (7 x 10-1) 2.4 (61) 4.8 (123) 7.2 (183) 0.05 (3 x 10.7) 1.2 (30) 2.4 (61) 3.6 (91) 0.01 (7 x 10.1) 0.24 (6) 0.48 (12) 0.72 (18) 18 Interlocking Concrete Pavement Magazine I November 2010 Conservation Des g n d Fbsource / Manual a 1N Language and t Guidelines for Updating LDca I Ordinances w � s A planning tool from the Northeastern Illinois Planning Commission and Chicago Wilderness f March 2003 CIIIC' AGD WILDF' KV' LSS Acknowledgements Acknowledgements This project has benefited from the expertise of the members of our Technical Advisory Committee, who have generously donated their time and attention to the development of the document. Project Technical Advisory Committee Ken Anderson Bill Grabarek Kane County Department of Village of Elburn Environmental Management Rich Guerard Steve Andras Wyndham Deerpoint Homes City of Aurora Chuck Hanlon Barbara Berlin Land Vision, Inc. Environmental Law and Policy Center bhn Heinz Furry Bigelow Village of Barrington Bigelow Homes Will Humphrey Lee Brown The Conservation Fund Teska Associates, Inc. Wade Joyner Steve Byers Kendall County Zoning Board of Appeals Illinois Nature Preserves Commission Jim Michels Ralph Coglianese Engineering Enterprises, Inc. Village of Villa Park Karen Miller Rbger Dahlstrom Kane County Development Department Northern Illinois University Tom Price Bruce Deason Conservation Design Forum Attainable Housing Alliance Ksenia Rudensiuk Colin Duesing The Conservation Foundation Will County Land Use Department Jm Schneider Todd Fagen Deven Ventures Land Strategies, Inc. Mike Shay Amy Furfori Will County Land Use Department Village of Montgomery Dien Shubart Bill Gain Campaign for Sensible Growth FbmpeSharpe & Associates Jeff Swano Enviro Impact Solutions Cover image: © Natural Lands Trust, Inc., Media, Flo. Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual We also have been fortunate to be able to draw on a collection of resources and examples of similar projects undertaken in other areas around the Midwest and the country. In particular, we would like to acknowledge the work of Randall Arendt; Kirby Date, Project Coordinator for the Countryside Program; and the University of Wisconsin Extension. Substantial portions of the model ordinance language and adapted from the Countryside Program's Conservation Development Resource Manual and from the University of W isconsin's An Ordinance for a Conservation Subdivision. Ideas for formatting and organization were adapted from the Center for Watershed Protection's Better Site Design. N IPC Project Team: Kathleen Odell, Sarah N erenberg, Lori Heringa ,Jeff Swano of Enviro Impact Solutions compiled the examples of economic benefits. Dennis Dreher (N IP;.) and Martin Jaffe (University of Illinois, Chicago) provided thorough editorial review. This project was funded through a grant program supported by the USDA Forest Service Northeastern Area, State and Private Forestry, and the US Fish & Wildlife Service, in support of Chicago Wilderness. USFS and USFWS grants of federal monies are administered by the Illinois Conservation Foundation. Additional funding was provided by Illinois Conservation 2000 and through voluntary financial support from local governments and the private sector. Overview Overview This Conservation Design Resource Manual has been funded in large part by Chicago Wilderness in keeping with its goal of involving local governments in the processes of restoring and maintaining regional biodiversity. The Resource Manual is written for use by local governments interested in modifying local comprehensive plans, zoning and subdivision ordinances, and other ordinances to accommodate the principles and practices of con- servation design. In many cases, communities are committed to enhancing local residents' quality of life through natural resource conservation. However, outdated plans and ordinances may work in opposition to these conser- vation goals. In this document, four principles and 13 practices for conservation design are identified and dis- cussed. For each of the 13 practices, model ordinance language is offered. Local governments can adapt this lan- guage to update their own local ordinances. Local governments, communities, developers, and homeowners all can contribute to the protection of biodiversity by observing the four principles identified here: • Develop Rexible Lot Design Standards • R-otect and Create Natural Landscape and Drainage Systems • Reduce Impervious Surface Areas • Implement Sustainable Stormwater Management Techniques The goal of this Fbsource manual is to provide ample information about conservation design principles and prac- tices, and to provide the necessary language to enable communities to implement conservation design at varying levels. The document is structured by practice, so that communities new to conservation design can begin with cautious modifications, while more experienced communities can more fully implement the ordinance revisions, which ultimately will lead to more comprehensive change. Communities that choose to implement conservation design will see a variety of benefits, including reduced flooding, improved water quality, enhanced biodiversity, higher property values, higher property tax revenues, and greater community cohesion. iii Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual iv Table of Contents Table of Contents Chapter 1: Introduction A Regional Conservation Perspective: Chicago Wilderness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 What is Conservation Design? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 What are the Benefits of Conservation Design? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 Why Update Local Ordinances? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 How to Use This Resource Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Chapter 2: Economic Benefits of Conservation Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 Benefits of Principle A-Develop Flexible Lot Design Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 Benefits of Principle B-Protect and Create Natural Landscapes and Drainage Systems . . . . . . . . . . . . . . .1 1 Benefits of Principle C-Reduce Impervious Surface Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 Benefits of Principle D-Implement Sustainable Stormwater Management Techniques . . . . . . . . . . . . . . . . .14 Chapter 3: Integrating Conservation Design into Local Pans and Ordinances A. Comprehensive Pans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 B. Zoning Ordinances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 C.Subdivision Ordinances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 D.Additional Local Ordinances to Review for Compatibility and Conflicts . . . . . . . . . . . . . . . . . . . . . . . .21 E. Working with Other Local Agencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 Chapter 4: Principles and Practices for Conservation Design Principle A. Develop Pexible Lot Design Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 Practice 1: Lot Size, Density, and Suggested Open Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 Practice 2: Arranging the Development Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 Practice 3: Building Setbacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33 Principle B. Protect and Create Natural Landscapes and Drainage Systems . . . . . . . . . . . . . . . . . . . . . . .35 Practice 4: Natural Area Protection and Resource Conservation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Practice 5: Land Compatible Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 Practice 6: Natural Landscaping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43 Practice 7: Natural Area Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46 V Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Principle C. Peduce Impervious Surface Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 Practice 8: Fbadway Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52 Practice 9: Parking Lot Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56 Practice 10: Vegetated Swales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59 Practice 11: Walkways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61 Practice 12: Driveway Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63 Practice 13: Fbof Rinoff Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65 Principle D. Implement Sustainable Stormwater Management Techniques . . . . . . . . . . . . . . . . . . . . . . . .67 Urban Runoff Mitigation Pan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69 Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73 Technical Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77 Appendices Appendix A: Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79 Appendix B: Determining the Allowable Density for Conservation Design . . . . . . . . . . . . . . . . . . . . . . . .83 Appendix C: Conservation Design Incentives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87 Appendix D: Special Service Area Financing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91 Appendix E CeDES System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93 vi Chapter 1 Introduction Chapter 1 Introduction This is one of a series of planning aids and manuals prepared by the Northeastern Illinois Ranning Commission (N IPC) as a service to local governments. The primary aim of this Conservation Design lbsource Manual is to assist communities in northeastern Illinois in creating regulations conducive to conservation design. Conservation design is a density neutral design system that takes into account the natural landscape and ecology of a development site and facilitates development while maintaining the most valuable natural features and func- tions of the site. The intent of this document is to provide practical alternatives to conventional zoning, subdivision, weed-control, and other development-related ordinances. In many cases, conventional ordinances conflict with the goals of con- servation design. With thoughtful revision, most existing ordinances can be modified and updated to not only allow, but encourage residential, commercial, and mixed-use development that is sensitive to both the natural ecol- ogy of the development site and economic needs of the community, land owner, and developer. Several practices outlined here apply most directly to residential subdivision design. However, conservation design is by no means limited to residential subdivisions. The principles apply to the design and construction of any type of development, and should be applied as widely as possible. A Fbgional Conservation Perspective: Chicago Wilderness In 1999, the Chicago Fbgion Biodiversity Council, or Chicago Wilderness, published its Biodiversity Ibcovery Ran for the northeastern Illinois region. The Biodiversity Recovery Ran is now a guiding document for the organ- ization and its more than 160 members; Chicago Wilderness seeks to support various projects that further the goals outlined in the Ran. Chicago Wilderness recognizes the importance of restoring, protecting, and manag- ing natural resources for the benefit and enjoyment of the residents of the Chicago region, for the economic growth that results from resource conservation, and for the environmental benefits realized. The Biodiversity Recovery Ran notes that while traditional land management agencies, such as forest preserve and conservation districts, have a clear mandate to protect biodiversity, the involvement of local governments also is critical if the goals of the Ran are to be achieved. This conclusion is born out by the fact that while 200,000 acres of natural land are protected under the umbrella of Chicago Wilderness, that leaves 90 percent of the land- scape subject to the planning, development, and management decisions of local governments. With the importance of local government participation in mind, the Biodiversity Recovery Ran states the follow- ing Goal for Local Governments: • Local and regional development policies should reflect the need to restore and maintain natural areas and biodiversity. 1 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Three Objectives for Local Governments are offered as methods of pursuing this goal: • Inventory sensitive habitats and identify opportunities for open space preservation and restoration. • Modify comprehensive plans, ordinances, and engineering practices to consider the impacts of development on biodiversity. • Incorporate provisions for biodiversity protection and restoration in the design plans for new development and redevelopment For more information about Chicago Wilderness and the Biodiversity Pecovery Plan, visit Chicago W ilderness on the web at www.chicagowilderness.org. For more information on an array of programs and techniques, see N IPC's publication Rotecting Nature in Your Community. (Available on the web at http://www.nipc.cog.il.us/ pro- tecting 20011/o2O.htm.) What is Conservation Design? Conservation design is a design system that takes into account the natural landscape and ecology of a develop- ment site and facilitates development while maintaining the most valuable natural features and functions of the site. Conservation design includes a collection of site design principles and practices that can be combined to cre- ate environmentally sound development. The main principles for conservation design are: 1. flexibility in site design and lot size, 2. thoughtful protection and management of natural areas, 3. reduction of impervious surface areas, and 4. sustainable stormwater management. A similar term, conservation development, is used to describe a development that is designed and constructed using the principles of conservation design. Conservation design is one of many tools available to communities committed to implementing sustainable development practices. Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs. In the context of this ordinance, conservation design is density neutral, meaning that designers plan development such that there is no overall loss of buildable units despite the conservation goals achieved on the site. Existing community standards for density and land use are not challenged here; rather, the practices given here offer alter- native design strategies that are more environmentally friendly while maintaining existing densities and land uses. In a residential conservation subdivision, for example, house lot size is substantially decreased, so that large areas of contiguous natural areas can be conserved with no net loss of housing units. In contrast, conventional devel- opment techniques often involve carving the development site into parcels such that the lots and road rights-0 f-way consume nearly all developable land without regard for the natural conditions on the site. Developments con- structed this way often have wide roads, minimal pedestrian access, and may be similar in character and design to many other neighborhoods. While development pressures are heavy in urban and urbanizing areas, increas- ing attention has been given to the necessity of preserving rural, agricultural, and important environmental lands even as development continues. 2 Chapter 1 Introduction The two graphics below (Conservation Design Forum, 2003)show the difference between conventional and con- servation design. Figure 1 shows a conventional subdivision layout, where the entire site is converted to roads and building lots. Figure 2 shows the same site with the same number of building lots laid out using conservation design practices. Note that natural areas and features of the site are preserved in the conservation design model, where this preservation is not possible using conventional design. 5 "-4- ! , i j I's %01 u b d . J MFO ° = 4F AIL Figure 1: Conventional Subdivision Layout(Conservation Design Forum, 2003) 3 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Ahat � I 4 tlp. i Figure 2: Conservation Subdivision Layout(Conservation Design Forum, 2003) What are the Benefits of Conservation Design? Through conservation design techniques, development and a healthy natural environment need not be mutually exclusive. The benefits of conservation design are substantial. Communities, developers, and homeowners all can benefit from well planned and implemented conservation design. The environment is another major beneficiary; while it may be difficult to quantify the value of an expanse of habitat, an undisturbed streambank, or a panoram- ic view protected from careless development, there is little disagreement that conserving these resources is an important aim. The benefits of conservation design fall roughly into three categories, quality of life benefits, environmental and biodiversity benefits, and economic benefits. Chapter 2, Economic Benefits of Conservation Design, lists in detail many economic benefits of the conservation design practices. 4 Chapter 1 Introduction Quality of Life Benefits Conservation design addresses concerns about community interaction and access to the natural environment. In addition to potentially conserving large areas of valuable natural resources, conservation design may create a variety of formal and informal public spaces within developments. These spaces create opportunities for neigh- bors and residents to meet and to build community together. Conservation design offers a variety of recreational prospects which may include organized group activities such as picnics or soccer games, biking or walking in natural areas, or observing the plants and wildlife that thrive in preserved habitats. For residents of conservation developments, these amenities can make a noticeable difference in the quality of daily life. Increasingly, notice is being given to the importance of community and social interaction in residential neighbor- hoods. Large homes, private backyards, and automobiles work together to make it possible for residents of con- ventional suburbs to spend all their time in private space without interacting with neighbors. While this type of pri- vacy was once considered an advantage, many people now seek alternatives to the conventional subdivision lifestyle. Conservation design offersjust such an alternative, and experience has shown that homes in these devel- opmentswill be increasingly valuable as homebuyers increasingly demand access to nature and community along with the residences they purchase. Environmental and Biodiversity Benefits Thoughtfully implemented conservation design practices are beneficial to the natural environment in a number of ways. • Rotected water quality • Reduced flooding • R-otected habitat and biodiversity • Rotected and recharged aquifers In short, while conventional development practices have historically led to flooding, degraded water quality, and habitat destruction, conservation design practices work together to counteract these negative consequences of development. Through the practice of conservation design, communities can protect valuable natural resources even while growing and expanding. Economic Benefits There are various economic benefits of conservation design. Communities, homeowners, and developers all can benefit economically from the use of the conservation design practices presented here. For a detailed discussion of these economic benefits, see Chapter 2, Economic Benefits of Conservation Design. 5 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Why Update Local Ordinances? The community, environmental, and economic benefits of conservation design are clear, and for most communi- ties, the use of conservation design makes sense for at least some types of development. While there are many ways to approach conservation design, the most effective way is to update local comprehensive plans, codes, and ordinances to reflect the community's commitment to conservation. Most importantly, conservation design should be allowed by right and should be the preferred option for many development projects. Presently, conservation design projects in most communities are approved through the Planned Unit Development (PUD)process. While the PUD process has the advantage of allowing the Plan Commission to maintain close over- sight of unconventional development projects, the process is burdensome for both developers and planning staff. A major benefit of updating local ordinances to allow conservation design by right is that it reduces the approval time for projects. This saves time and aggravation for all parties involved in the development process, and as a result also saves money. Conservation Design and Sprawl An occasional critique of conservation design is that while it is presented as an environmentally responsible devel- opment form, it encourages development of previously undisturbed (greenfield) sites on the urban fringe and ulti- mately leads to sprawl, albeit more responsible sprawl. Several responses can be made to this critique. First, development on the urban fringe is inevitable. Conservation design recognizes this inevitability and defines methods by which development can be sensitive to the natural areas and systems of the development site. Second, conservation design does not position itself as a comprehensive solution to the challenges of urban and suburban development. The more inclusive umbrella of "sustainable development" seeks to address these chal- lenges more fully, while conservation design addresses specific situations. In keeping with this limitation, please keep in mind that this resource manual is not a comprehensive treatment of sustainable development practices. A comprehensive document would include discussion and ordinance language for Traditional Neighborhood Development, mixed-use development, urban infill development, New Urbanism, brownfield redevelopment, ener- gy efficiency, farmland preservation, and other practices. This resource manual focuses exclusively on conserva- tion design. While a comprehensive resource manual is beyond the scope of this project, it is anticipated that future projects will address other aspects of sustainability. Finally, the development principles and practices offered here are highly adaptable. While all practices may not be relevant to all development projects, certainly the environmental impact of nearly any development can be reduced through the employment of conservation design practices. When planning revisions to local codes and ordinances, consider that while some practices may be applicable only in lower density zones, others may apply to all development regardless of its location. 6 Chapter 1 Introduction How to Use This Fbsource Manual This resource manual is meant as a guide and is not intended to be adopted "asis." Rather, it allows each com- munity to adapt the language and concepts to best fit the unique circumstances of that community. The model ordinance language has not been organized by type of ordinance (subdivision, zoning, etc.). fbther, in order to respond to the unique regulatory environment of each community, the information has been organized by the principles and practices of conservation design. To use the resource manual, begin by selecting the prac- tices that would be most applicable to your community, then adapt the model language given with each concept to update the appropriate existing ordinance. Communities desiring to implement conservation design in place of the Planned Unit Development process should consider incorporating all or nearly all of the practices into the zon- ing and subdivision ordinances. This large scale adoption is most helpful in creating a predictable development approval process, which will encourage developers to utilize the conservation design practices. To facilitate the amendment of local ordinances, introductory language to be added to zoning and subdivision ordinances is also provided. Again, although several of the practices apply most directly to residential subdivi- sion developments, most of the suggested practices offered here can be adapted to enhance nearly any type of development. Chapters 3 and 4 of this resource manual contain the majority of the information and language for conservation design. Chapter 3, Integrating Conservation Design Principles into Local Plans and Ordinances, addresses the basics of enabling conservation subdivision design in your local comprehensive plan and development ordi- nances. Chapter 4, Site Design Practices for Conservation Design, gives detailed information about the principles and practices suggested for conservation design, including ordinance language to enable each practice. Chapter 4 also lists several additional references for the four major conservation design principles; these references should be consulted by communities wishing to conduct additional research into the principle. Additional information is provided in the Appendices. Of particular interest is Appendix A, which contains a list of definitions for conser- vation design. Appendices B— E provide expanded technical discussions of key concepts. While most ordinances contain a section on the development review process, such language was not included here because the review process varies widely by locality. Text in [brackets] indicates terms that need to be written specifically for the local jurisdiction, such as the jurisdic- tion name. Similarly, blank lines( in the model ordinance language should be filled in. Suggestions for fill- ing these blanks will be provided in the commentary. Definitions may need to be added to the appropriate por- tion of the local code if they are not elsewhere used or if they are used in a different context. Depending on the structure of the local code, some elements of the ordinance may need to be inserted into the zoning code and oth- ers may need to be added to the subdivision or development ordinance. It is impossible to draft a model ordinance to fit perfectly into all of the innumerable varieties of regulatory pro- grams that exist at the local government level. The ordinance language given here is designed to be adapted to the unique characteristics of each local government organization. The ordinance language can be combined with or replace existing ordinances, such as weed ordinances, which address issues covered by the resource manual. It is presumed that some provisions of the ordinance will be modified or possibly even rejected altogether. Some provisions may have to be added. 7 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Introduction to Principles and Practices for Conservation Design The following four principles have been identified as essential considerations in the Conservation Design process: 1. Develop Rexible Lot Design Standards 2. Protect and Create Natural Areas and Drainage Systems 3. (educe Impervious Surface Areas 4. Implement Sustainable Stormwater Management Techniques Thirteen specific site design practices are presented to implement these principles. A list of these appears below. The practices are organized by principle, with each practice being listed under the subsection for the most rele- vant principle. The practices are designed to have specific suggestions, guidelines, and language for implemen- tation. The principles and practices outlined here are discussed in detail in Chapter 4. Principle A. Develop Flexible Lot Design Standards Practice 1. Lot Size, Density, and Suggested Open Space Practice 2. Arranging the Development Site Practice 3. Building Setbacks Principle B. Protect and Create Natural Landscapes and Drainage Systems Practice 4. Natural Area Protection and Conservation Practice 5. Natural Landscape Sensitivity Practice 6. Natural Landscaping Practice 7. Open Space Management Principle C. Reduce Impervious Surface Areas Practice 8. Fbadway Design Practice 9. Parking Lot Design Practice 10. Vegetated Swales Practice 11. Walkways Practice 12. Driveway Design Practice 13. Fbof Funoff Management Principle D. Implement Sustainable Stormwater Management Techniques Urban FUnoff Mitigation Ran 8 Chapter 2 Economic Benefits of Conservation Design Chapter 2 : Economic Benefits of Conservation Design The economic benefits of conservation design are interrelated among the various conservation design principles. Few principles have stand alone economic benefits, but rather one benefit often produces another, typically pro- ducing environmental benefits as well; as a result it is useful for readers to consider the benefits across all four principles, below. In addition, the economic benefits of conservation design accrue to communities, homeowners, and developers. According to Arendt (1999), the primary economic benefits of conservation design can be summarized as: • greater areas of preserved open space, • lower construction and maintenance costs associated with reduced infrastructure, • real estate value appreciation, and • a marketing and sales advantage. Actual economic benefits in real dollar terms are difficult to present in a one-size-fits-all basis and cannot be pre- sented herein. Local costs of supplies, labor, and equipment vary across the Chicago metropolitan region, and net costs are affected by the size of a particular development and the extent to which it incorporates the various conservation design practices. In addition, specific longAerm maintenance costs need to be considered. As a result, each section below provides examples of economic benefits realized by various communities that have employed the conservation design practices detailed in the next chapter. By illustrating the factors involved, the scale of the benefit, and how they accrue to the community, homeowners, and developers, communities can for- mulate how the economic benefits will apply to them. Please note that many of these benefits cross over various principles. Benefits of Principle A—Develop Flexible Lot Design Standards Practice 1. Lot Size, Density, and Suggested Open Space R-actice 2. Arranging the Development Site Practice 3. Building Setbacks Community Benefits • Minimizes stormwater runoff and its negative impacts. • Reserves natural resources and features. • Roduces a broader range of marketable housing. • Clarifies and simplifies the development review process. • Fbduces the municipal cost of open space, since natural areas are acquired more economically through conservation design than through outright purchase. 0 Conservation design provides open spaces and buffers without the need to incur direct public expenditures to obtain or protect such areas. This results in a significant cost savings for municipalities while still deriving the social benefits of open space. Furthermore, municipalities can increase the value and the size of any existing public parkland by implementing zoning and other ordinances that specify adjacent parkland buffers as a required design element in new subdivisions(Arendt 1999). 9 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual • Reduces long-term maintenance and development costs, since infrastructure(roads, sewer, streetlights, water, etc.) is reduced. • More compact layouts result in shorter sewer and water connections and arterial roads. This reduces the public sector's long-term infrastructure maintenance costs. CH2MHill found that although demand for public services is relatively insensitive to lot size or density, the public service costs of compact cluster developments were still 4 to 8 percent lower than the cost for large lot developments(CW P 1995). • Increases the community real estate tax base. It has been found that property values in conservation developments are considerably higher than conventional developments (see Homeowner Benefits below). As property values increase, so too do real estate property taxes, which are often a municipality's prime sources of funds. Homeowner Benefits • Increases property values. 0 Property values in developments where housesare grouped together have been found to appreciate more rapidly than homes in conventional developments. For example, a Massachusetts study compared two subdivisions where homes in developments of similar densities(two dwellings per acre) initially sold for similar prices. Over a 20-year period, the conservation development homes (built on quarter-acre lots) sold for an average $17,000 more than their counterparts(built on half-acre lots). This resulted in a 13% price differential attributable to the 36-acre open space amenity available at the grouped development (Arendt 1999). 0 In an Ohio conservation designed subdivision, open space and lot buffering added a 10% price premium over other homes within the same subdivision. Further, these homes(on 0.6-acre lots) had a 3% price premium over larger 1 acre lots in a nearby conventional subdivision. Home buyers in this case were willing to pay a premium for smaller lots when the value of open space was associated with a home purchase (The Countryside Program 1998). 0 A variety of real estate appraisal studies across the country have found that real estate values of individual properties are higher the closer they are to open space. For example, in 1974 a study was conducted in Fhiladelphia of properties located near a 1,300-acre park. The study found that properties at a distance of 2,500 feet from the park had values that were 4.2% higher than properties located farther away. Properties located 1,000 feet from the park had values that were 9% higher, and a property only 40 feet from the park had a 33% higher value. The study also concluded that each acre of parkland generated about $2,600 in increased property values(Brabec 1992). 0 Similarly, a 1978 study in Boulder, Colorado, found that house prices declined by an average of$4.20 for each foot of distance away from a greenway. Homes adjacent to the greenway were found to be valued 32% higher than similar residences located 3,000 feet away (Brabec 1992). • Enhances access to recreational opportunities is enhanced, as more natural areas are created. 0 Home buyers value the social and recreational amenities associated with the open space. This creates an additional economic benefit to households by reducing automotive transportation that would otherwise be needed to travel to social and recreational opportunities(Arendt 1999). • Reduces landscape maintenance needs. (See Principle B, below, for specific examples.) Developer Benefits • Increases predictability of development approval process. • Enhances marketability of homes. • Lowers development costs. 0 The primary economic benefits of grouping homes are the reduced construction costs associated with developments. In general, construction cost savings of 25% or more have been realized throughout the 10 Chapter 2 Economic Benefits of Conservation Design country when grouping large lot (1 acre or more) developments. These cost savings are not as great when smaller, half-acre lots are grouped, where a cost savings of about 10% has been realized (CW P 1995). 0 In 1992, CH2MHill found that as the distance between individual dwelling units decreases, the total cost of subdivision infrastructure declines proportionally (CW P 1995). 0 Depending on how open space is incorporated into residential site design and how stormwater is managed, construction/ infrastructure cost savings of between 11% and 66% can be realized (CW P 1998). • Enhances design flexibility. • Saves development costs when natural areas are transferred to the community. Benefits of Principle B—Protect and Create Natural Landscapes and Drainage Systems Practice 4. Natural Area Protection and Conservation Practice 5. Natural Landscape Sensitivity Practice 6. Natural Landscaping Practice 7. Open Space Management Community Benefits • Reduces flooding and stormwater management costs. 0 Buffers provide temporary storage of floodwaters in headwater streams, which reduces the height of a flood crest and the subsequent cost damages to downstream communities(CW P 1995). • Pbduces long-term maintenance costs. 0 Unlike storm sewers, curbs, gutters, and sewer inlets, swales and filter strips theoretically never need to incur replacement costs (except in cases of extreme erosion), but rather require periodic maintenance consisting of sediment or debris removal and general cleaning (N IPC 1997a). 0 Filter strips may reduce maintenance costs for components of downstream drainage systems because they remove sediment and other pollutants(N IPC 1997a). 0 Swale maintenance costs can be reduced if upstream sources of sediment—particularly from construction activities—are well controlled, and if local ordinances are enforced prohibiting homeowners from dumping materials into swales(N IPC 1997a). • Meets increasing demand for public open space. 0 Natural landscaping can serve as a buffer to existing preserved natural areas, thereby increasing the size of the natural area. This provides a continuous natural ecosystem setting and enhances the "connection to nature" that is important to communities(The Countryside Program 1998). • Allows connections to existing natural areas, open space, greenways, and trails. • Reduces soil erosion. • Reduces need for fertilizer and pesticides. • Conserves local, often rural, areas of biodiversity. • Preserves rare, threatened, and endangered species. • Increases opportunity for passive recreational and educational activities - fosters health and fitness of residents. 11 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual • Improves air and water quality, and controls urban heat. 0 The Chicago urban forest canopy covers about 11 percent of the city's total land area. This canopy removes 15 metric tons of carbon monoxide, 84 metric tons of sulfur dioxide, 89 metric tons of nitrogen dioxide, 191 metric tons of ozone, and 212 metric tons of particulates. This saves the municipal government more than $1 million annually in what would otherwise be spent on traditional pollution mitigation efforts(Scheer 2002). Homeowner Benefits • Increases property values. (See R-inciple A, above.) • Decreases maintenance costs. (Also see community benefits, above.) 0 Turf grasses require fertilizers, water, pesticides and other measures annually to keep lawns in quality condition (The Countryside Program 1998). Native landscapes require weed control and minimal watering in the first few years to get established, then occasional mowing or controlled burns for long-term management (Rzzo & Associates 2001). 0 Smaller yards that have natural landscaping require less maintenance thereby not only reducing costs but also allowing people more free time to spend enjoying the open space amenities located around them(Arendt 1999). • Enhances aesthetics. • Maintains productive land uses. 0 Natural area protection can conserve highly productive agricultural land. For example, R•airie Crossing has a 10-acre, community-supported organic farm from which 100 member families receive a bushel of fresh produce and cut flowers each week during the 20-week growing season for an annual subscription of$400. Thus, the conservation effort is able to generate revenues(Brabec 1992). Developer Benefits • Reduces landscaping and other installation costs. 0 Installation and maintenance costs are lower for natural (native)landscaping compared with common turf grasses. Rzzo compared the installation and maintenance costs of new turf grass lawn from seed with the costs of native landscaping with seed in an area less than one acre. He found that installation costs were $5,330 for native landscaping and $8,190 for turf grass. Thus, native landscaping installation showed a 35 percent cost savings over turf grass. Over a 10 year period, the cost to install and maintain native plantings came to $14,152. The same costs for turf grass came to $47,497. Thus, native landscaping installation and long-term O&M costs showed a 70 percent cost savings over turf grass (Rzzo & Associates 2001). 0 In a 1996 study, the cost to install and maintain native plantings over a 10year period came to $9,800 per acre. The same costs for Kentucky blue grass came to $59,400 per acre. Thus, native landscaping installation and long-term O&M costs showed an 83 percent cost savings over turf grass(N IPC 1997b). 0 A comparison of annual maintenance costs found that open space costs about $75 per acre to manage, lawns cost about $255 per acre, and passive recreation areas (trails, bike paths, etc.) cost about $200 per acre (CW P 1998). • In a California development, virtually all the runoff flows into a gravel-filled infiltration trench meandering through open areas behind most of the homes. This natural stormwater management design saved approximately $800 per household in engineering and construction costs, which enabled the developer to increase the landscaping budget by a like amount. • Enhances marketing potential. 0 The marketability of a development in enhanced by the lower maintenance aspects associated with native landscaping and smaller lawns. A 1995 Newsweek survey found that twoAncome families prefer smaller lawns in order to reduce their lawn maintenance activities(CW P 1998). • Enhances developer reputation for innovative development. 12 Chapter 2 Economic Benefits of Conservation Design Benefits of Principle C—Fbduce Impervious Surface Areas Practice 8. Fbadway Design Practice 9. Parking Lot Design Practice 10. Vegetated Swales Practice 11. Walkways Practice 12. Driveway Design Practice 13. Fbof Fdinoff Management Community Benefits • Decreases demand for stormwater runoff management. • Peduces municipal maintenance costs. 0 Reduced residential street widths and lengths reduce the associated IongTerm operation and maintenance costs of local infrastructure (CW P 1998). These costs include 1) road repair and replacement, 2) utility repair and replacement, 3) snow removal, 4) inspections, and 5) street sweeping. • Reduces municipal energy costs. 0 Impervious surfaces such as roads and roofs are known to create heat islands, trigger chemical reactions that produce smog, and boost energy demand. Reduced impervious surfaces (along with natural area landscaping with trees) can reduce energy costs(American City & County 2000). • Improves water quality and quantity. 0 In the Chicagoland area, Lake Michigan water is not available to most newly developing areas, and water rates are increasing to the existing populations served. Feducing impervious surface area allows more stormwater to infiltrate into the ground and recharge groundwater aquifers. This provides a valuable natural resource, which could lead to greater water supplies in developing areas. Homeowner Benefits • Increases chances of friendly interaction with neighbors, since compact transportation network boosts proximity to neighbors. • Increases biodiversity in nearby wetlands and water bodies, since impervious areas are reduced, saving habitats. • Reduces residential street widths that allow parking tend to slow drivers down, creating safer roads. 0 A 1998 study by Peter Swift illustrates that as street width widens, accidents per mile per year increases exponentially, and that the safest residential street width is 24 feet (Shrift 1998). Developer Benefits • Decreases development costs. 0 Reduced impervious surface area immediately results in reduced infrastructure engineering and construction costs. To the extent that street pavement is reduced, the size and cost of stormwater management facilities also can be lessened (Arendt 1999). F=or each increment of impervious cover that is reduced, developers gain a proportional reduction in infrastructure construction costs(CW P 1995). 0 The cost of a curb,and-g utter/storm drain pipe system ranges from $40 to $50 per running foot in 1990 dollars, which is about 2 to 3 times more expensive than an engineered swale (CW P 1998). 0 Fbadside swales with culverts at road and driveway crossings are generally less costly to construct than curb-and-gutter storm sewers. In a Lake County, Illinois study the cost savings were about $70,000 per mile of road for a typical residential subdivision with half-acre lots, or nearly $800 per residence (N IPC 1997a). 13 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual 0 Construction costs for paving are approximately $15 per square yard in 1998 dollars. Peducing the width of a 300 foot long residential street from 28 feet to 18 feet would reduce overall imperviousness by 35% and construction costs by $5,000 (CW P 1998). 0 The cost savings associated with eliminating just one parking space is about $1,100 (in 1990 dollars). Additional cost savings can be realized in the form of lower costs for storm drains, Best Management Practices(BM PS), and associated maintenance (CW P 1995). Benefits of Principle D—Implement Sustainable Stormwater Management Techniques Urban Rinoff Mitigation Plan • Increases marketability - developments with improved stormwater management facilities are more marketable because they provide aesthetic features such as rain gardens, wet detention basins, and natural drainage areas that attract wildlife. • Because stormwater management benefits cross the various principles and practices, only the above economic benefit is listed here. Other benefits related to stormwater management are distributed throughout Principles A, B, and C. 14 Chapter 3 Integrating Conservation Design Principles into Local Pans and Ordinances Chapter 3 Integrating Conservation Design Principles into LDcal Plans and Ordinances We recognize that the communities that choose to enable conservation design in local ordinances will have a vari- ety of regulatory environments. For that reason, this resource manual is structured to offer ordinance language for various site design techniques. Each community will choose which practices to adopt, and then through review of existing ordinances may find it necessary to update the most relevant sections of zoning, subdivision, or other reg- ulations. A few concepts will apply to nearly every regulatory environment. These are given here as preparatory work to be undertaken by any community embarking on the process of updating local ordinances for conservation design. For communities looking for a more in-depth discussion of the processes involved in planning and enabling con- servation design, refer to Iandall Arendt's books Growing Greener and Conservation Design for Subdivisions. The sections that follow will address Conservation Design as it relates to: • Comprehensive Rans • Zoning Ordinances • Subdivision Ordinances • Other Existing Ordinances • Other Local Departments and Agencies A. Comprehensive Plans Update the community comprehensive plan to reflect a commitment to conservation design goals. A comprehensive plan establishes a community's goals, objectives, and policies, and shows an overall pattern of land use that a community believes will help achieve these goals. Updating and maintaining a current compre- hensive plan is an important way to maintain communication between the many stakeholders in the development of your community. The comprehensive plan sets the tone for the type of improvements and developments that your community is seeking, and gives cues to residents and developers about the kinds of projects that are likely to be supported. For those communities interested in protecting unique local natural, agricultural, cultural and historical elements through conservation design practices, the comprehensive plan provides an opportunity to create a strong foun- dation for regulatory changes. Strategies 1. Rovide background information, including information about the heritage of the community, and the natural, agricultural, historical, and cultural resources that define the quality of life for community residents. 2. Include conservation goals and objectives in the goals and objectives section of the plan. These may include protection of sensitive natural areas, habitat protection, sustainable water resource management, and other goals. 15 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual 3. Complete a community resource inventory and include this information in the plan. 4. Include a greenway or green infrastructure plan for the community within the comprehensive plan. 5. Be certain that the plan is formally adopted as a blueprint to guide future development in the community. 6. Wherever possible, repeat language from the comprehensive plan in the regulatory ordinances. (Arendt 1999, 20). For more technical information, N IPC's Environmental Considerations in Comprehensive Planning and Protecting Nature in Your Community provide detailed practical advice for updating the community comprehensive plan to include environmental considerations. Copies of these documents are available from N IPC's publications department; call (312) 454-0400 with inquiries. Protecting Nature also is available on the web at http://www.nipc.cog.il.us/ protecting 2001%20.htm. B. Zoning Ordinances Ensure that conservation design is encouraged under the community zoning ordinance. Zoning ordinances must be reviewed and updated to allow conservation design in appropriate districts. In most communities, conservation design currently can be accomplished only through the Panned Unit Development (PUD) process. The PUD process has some major advantages. By requiring unconventional developments to go through this process, the community maintains a high level of control. Also, the public has a greater opportunity to review and comment on proposals. However, one of the primary reasons developers give for avoiding con- servation design is the time consuming and uncertain nature of this process. In most cases, no special review or approval is required to build conventional developments, while it is complicated and time intensive to build con- servation developments. With regulations like these in place, communities may inadvertently create obstacles to progressive growth strategies such as conservation design. The minimum goal of updating the zoning ordinance is to create a level `playing field,' where conservation design enjoys regulatory support equivalent to conventional development. Communities that are committed to the out- comes of conservation design may wish to strengthen the language even more, enough to tilt the `playing field' toward conservation. The recommended approach is to allow conservation development by right in the zoning, so that no special approvals are required. The following are three recommended approaches to including conservation design in a local zoning ordinance. Any of these zoning options creates a regulatory environment where conservation design is permitted by right. In all cases, the conservation zoning is in place, and the conservation design option is available for the property owner to utilize. Since no additional time or expense is needed to legislatively create the enabling conservation zoning, there is greater opportunity that this option will be selected over the standard subdivision option. Additionally, the community has indicated to its residents where and under what conditions conservation design is appropriate. In each option, once the property is zoned, subsequent project review occurs administratively by the planning department or similar administrative body. In some cases communities may choose to combine two or more of these options to meet the conservation needs of different areas of the community. 16 Chapter 3 Integrating Conservation Design Principles into Local Pans and Ordinances Option 1: The municipality or county adds conservation design (in conjunction with a particular set of land uses)to the list of permitted uses in an existing district. Option 2: The municipality or county creates a Conservation Design District and applies it as an "overlay" district to those selected locations that the community deems suitable for conservation design. In this option, the property owner has the option of developing the land according to the underlying standard district regulations or the overlay conservation design option. With the overlay district, conservation design is only an option in those locations with the overlay designation. (See Appendix C, Conservation Design Incentives, for a discussion of how developers might be encouraged to choose to exercise the conservation design option.) Option 3: The municipality or county designates certain districts on the zoning map as Conservation Design Districts; conservation design is the required design practice in these areas. This more aggressive strategy requires conservation design practices to be utilized in designated areas. Other strategies exist, but the above three are recommended. Strategies not recommended include creating a con- servation design district that can be utilized at the request of the property owner and establishing conservation design as a conditional use in some districts. These strategies do not allow conservation design as a permitted use and as such are not suggested as long term solutions. To determine where conservation zoning should be applied, each community will consider the following questions through the comprehensive planning process: 1. What resources in the community are most important to conserve? 2. Where is the application of conservation design most beneficial? 3. What standards are appropriate in the conservation design regulations to conserve the natural resources and otherwise achieve the community's objectives? Conservation Design in Every Project Whatever decision is made regarding conservation zoning, some combination of the site design practices out- lined in Chapter 4 is appropriate for all types of development. Whether or not a proposed development is for- mally considered a conservation design under the zoning code, all of the practices should be encouraged or required where appropriate. For this reason, as each community reviews its ordinances, many practices may be enacted for all development, regardless of zoning classification. The following model zoning ordinance language can be adapted to add conservation design to the existing zon- ing ordinance in conjunction with particular land uses in appropriate zoning districts. This language allows con- servation design as outlined in Option 1, above. Introductory language is also provided that can be adapted to formally introduce the community's commitment to conservation principles. 17 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Model Zoning Ordinance Language Commentary (Adapted from the Countryside Program) Purpose The primary objective of conservation design zoning These objectives should be carefully worded to include is to promote the health and safety of the community the specific characteristics within the community that through the application of flexible land development have been determined to be priorities for conserva- techniques in the arrangement and construction of tion. dwelling units, roads, surface drainage, and under- ground improvements. Such flexibility is intended to retain for the property owner the development rights (the number of residential dwelling units)that are per- mitted under the existing conventional zoning for the property while encouraging environmentally responsi- ble development. These regulations are intended to achieve these corol- lary purposes: A. To maximize protection of the community's natural resources by recognizing the following goals: 1. Protect and enhance biodiversity as stated Points 1-10 are examples of the types of conservation in the Chicago Wilderness Biodiversity goals a community may wish to set. Each community Pbecovery Pan; can select the goals that best match its own, or can 2. Minimize development on and destruction draft new statements better suited to community goals of sensitive natural resource areas and and intentions. (Note: Because of road and stormwa- wildlife habitats; ter design, these goals should be listed in the subdivi- 3. Fbduce the quantity and improve the sion ordinance language as well; it is strongly sug- quality of stormwater runoff from expected gested to repeat the language in both places and to development; make the list of goals identical.) 4. Provide a wider range of feasible sites to locate stormwater Best Management Practices(BM Fs); 5. Minimize impervious surface area; 6. Fbduce potential pressure to encroach on resource buffer areas; 7. Reduce soil erosion potential; 8. Reduce the capital cost of development; 9. Feduce the cost of public services required by the development; and 10.Increase future property values. B. To reduce the time and effort required for administrative review of conservation design proposals, for the benefit of both the planning department and the developer. 18 Chapter 3 Integrating Conservation Design Principles into Local Pans and Ordinances Model Zoning Ordinance Language (continued) Commentary Permitted Uses The following uses shall be permitted based on the The section references here should be completed with type of development proposed: numbers of the sections of the zoning or subdivision ordinances that define conservation design. A. Conservation design in accordance with the regulations set forth in Sections_through See definition of "dwelling" for more information, or inclusive: use community's existing land use definitions. The 1. Detached single-family dwellings; more flexibility the applicant has in the arrangement 2. Single-family cluster dwellings; of units, the greater the ability to effectively group the 3. Single-family attached dwellings; units and conserve meaningful natural areas and envi- 4. Multi-family dwellings; ronmental resources, thus achieving the conservation 5. Recreation facilities; objectives. Attached units are strongly suggested 6. Commercial, industrial, and office facilities; when the permitted density is two units per acre or 7. Natural areas; higher, otherwise it may not be possible to achieve 8. Combinations of the above, known as significant open space or to aggregate the natural mixed-use development. areas in a desirable manner. B. [OTHER PEWITTED USE] Depending on the zoning district, some of the uses list- ed here may not be appropriate. C. [OTHER PERMITTED USE] Conservation design is added to the list of permitted uses if used in conjunction with a specific set of land uses within designated zones. The other permitted uses (single-family residential, mixed-use, agriculture, etc.) remain in effect as well. C. Subdivision Ordinances Rewrite sections of the subdivision ordinance to ensure sufficient flexibility for conservation design. Language is offered in Chapter 4 for updating ordinances with regard to specific site design practices. The following model ordinance language can be incorporated into the subdivision ordinance to formally introduce the community's commitment to conservation design. 19 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Model Subdivision Preamble Language Commentary (Adapted from the Countryside Program) Purpose The[Municipality or County] has established (or may estab- This statement of purpose is offered as an example. lish)conservation design standards and procedures within Language should be adapted and revised to suit the [Municipality or County] zoning resolutions. Therefore, it is goals of each community. intended that subdivision regulations are sufficiently flexible to carry out the conservation design objectiveswhile ensur- ing that such development is consistent with the underlying purposes of these subdivision regulations. Conservation design is intended to encourage more efficient use of land and public services through uni- fied development that is principally intended to protect biodiversity, conserve community resources, preserve natural areas, and protect the health and safety of the community. These objectives are accomplished through land development techniques set forth in municipality or county zoning resolutions that permit flexibility in the arrangement and construction of dwelling units, roads, and other built elements. Therefore, this Chapter establishes reasonable stan- dards and criteria to likewise permit sufficient flexibil- ity in the development of subdivisions to be consistent with municipality or county conservation design regu- lations, to maximize the achievement of conservation design objectives and to promote the following corol- lary purposes: 1. Protect and enhance biodiversity as stated in the Similar to the introductory language above, points 1- Chicago Wilderness Biodiversity Pecovery Ran; 10 are examples of the types of conservation goals a 2. Minimize development on and destruction of community may wish to set. Each community can sensitive natural resource areas and wildlife select the goals that best match its own, or can draft habitats; new statements better suited to community goals and 3. Fbduce the quantity and improve the quality intentions. (Note: These goals may be listed in the zon- of stormwater runoff from expected ing ordinance language as well; it is strongly suggest- development; ed to repeat the language in both places and to make 4. Provide a wider range of feasible sites to the list of goals identical.) locate stormwater Best Management Practices (BM Psi); 5. Minimize impervious surface area; 6. Reduce potential pressure to encroach on resource buffer areas; 7. Reduce soil erosion potential; 8. Reduce the capital cost of development; 9. Reduce the cost of public services required by the development; and 10. Increase future property values. 20 Chapter 3 Integrating Conservation Design Principles into Local Pans and Ordinances D. Additional Local Ordinances to Review for Compatibility and Conflicts Review all relevant municipal development ordinances for consistency with conservation design goals. In the process of updating zoning and subdivision ordinances, it is beneficial to review other existing municipal ordinances for consistency. Work with your municipal attorney to determine if changes should be made to other ordinances. While it may be challenging to address the various ordinances in place in the community, this is an important step for the success of conservation design. Working with these ordinances will require working with the various boards and agencies that administer them. For example, if you have added a section to your subdivision ordinance encouraging or requiring natural land- scaping, review any existing landscaping or weed ordinances. Do these contain language contradictory to the revised subdivision ordinance? Similarly, community stormwater ordinances often encourage natural drainage Best Management Practices(BMPs), but often the subdivision ordinances of these same communities require curb and gutter construction and storm sewers. Remove any of these types of contradictions or obstacles to conserva- tion design. Fbplace these sections with updated language. Consider consolidating ordinances that are repetitious. Ordinances to consider • Landscaping ordinance • Historic preservation ordinance • Weed ordinance • On-street parking ordinance • Stormwater ordinance • Soil erosion and sediment control ordinance • Roodplain and wetland ordinances • Tree preservation ordinance • Highway access control ordinance • Fire code • Fbadway design standards • Building code • Wastewater ordinance E. Working with Other Local Agencies Work closely with other agencies and departments. It is important for planning departments to be aware of the effect that ordinance changes such as the ones suggested here have on other municipal departments. For example • as street width and turning radius requirements are adjusted, the fire department may express concerns about safe passage in case of emergency, • the engineering department will be substantially affected when stormwater management practices are changed, • the local Health Department should be consulted if developments include innovative wastewater treatment p ra cti ces. For these reasons, it is important to encourage wide involvement in the update processes. Through communica- tion and cooperation, most concerns can be effectively addressed and resolved. Conversely, if other departments are not included in the revision process, you may find that your revised ordinances will not pass final review. 21 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual 22 Chapter 4 Principles And Practices For Conservation Design Chapter 4 Principles And Practices For Conservation Design Principle A. Develop Rexible Lot Design Standards Rexible lot design standards can lead to attractive, comfortable developments while simultaneously optimizing the protection of natural systems and conserving natural areas. Discussion Standard requirements for lot size, density, dispersion, and lot setbacks often put up inadvertent barriers to environmen- tally responsible conservation development. This is especially true of zoning and subdivision regulations pertaining to residential subdivisions, but this discussion is pertinent for all types of development. Often, traditional regulations lead to developments where all the land is divided into building lots and streets. N atural areas in such developments are often limited to strictly undevelopable wetlands, steep slopes, floodplains, and stormwater management areas. Conventional lot design requirements are based on the idea that homeowners require large expanses of lawn (in the form of private front, back, and sideyards)between themselves and their neighbors, and that the more spacious the indi- vidual lot, the more desirable the property will be. In fact, comfortable home sites do not require large lots, long set- backs, and wide spacing between buildings. When lot design is approached with new flexibility, it becomes possible to design developments that maximize both the number and the attractiveness of buildings while simultaneously opti- mizing the protection of natural systems and conserving natural areas. These results can be achieved with very simple changes to local zoning and subdivision ordinances. The three practices described in this section offer technical sug- gestions for modifying these local codes to increase design flexibility. Here we introduce the concept of density neutral development. Developers and landowners unfamiliar with conservation design often express concern that natural area and open space set-asides translate to an overall reduction in buildable lots. In reality, however, a major aim of conservation design is to conserve the total number of buildable lots. (See Appendix B, Determining the Allowable Density for Conservation Design.)The flexible lot design standards outlined in this section are the tools that make density neutral conservation design possible; for this reason, these practices are par- ticularly important to the economic viability of conservation design and should be included in any ordinance updates. Benefits, Examples, and Resources Updating lot design standards and regulations can be beneficial to the local community, future homeowners, and the developer of the site. See Chapter 2 for a full discussion of the economic benefits of this principle. Community Benefits • Stormwater runoff and its negative impacts are minimized. • Natural resources and features are preserved. Homeowner Benefits • R-operty values increase. • Access to recreational opportunities is enhanced by increased natural areas. Developer Benefits • Increased predictability of development approval process. • Marketability of homes is enhanced. 23 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Practice 1 : Lot Sze, Density, and Suggested Open Space Biminate minimum lot size requirements; rather, regulate overall density of development. Rather than controlling density by increasing lot size requirements, conservation design experts recommend imple- menting standards for overall density on a given site without regulating the lot size. With this method, the devel- oper is permitted to construct a fixed number of housing units regardless of lot size. In other words, conservation design is density neutral. (For a detailed discussion of density in conservation developments, see the Appendix B, Determining the Allowable Density for Conservation Design.) By eliminating minimum lot size requirements, communities encourage creative developments designed to be both profitable and sensitive to the pre-development character of the development site and the community at large. Ordinances without minimum lot size requirements make way for increased natural areas within developments. These natural areas provide opportunity for recreation, maintain habitats, preserve scenic views, and enhance community open space networks. Figures 3 and 4, below, (Teska Associates, Inc., 2000)show example configurations that can be used to arrange the same number of housing units on a development site, with the resulting differences in building massing and natural areas. X L � I IL a r Figure 3: Conventional Layout on Development Site Teska Associate4 Inc. -2000 24 Chapter 4 Principles And Practices For Conservation Design —77 I T, i � 1 A � — ` I l � I - 1 Fgure 4: Conservation Design Layout on Development Ste Teska Associated Inc. -2000 Some conservation design experts recommend the implementation of a maximum lot size to impose an absolute limit on oversized lots. This resource manual, however, advocates that all lot size restrictions be removed from the zoning ordinance, to make way for creative solutions such as a single lot development with all housing managed as condominiums. Lot Size, Density, and Open Space The basic principle underlying the practice of conservation design is the protection of natural and cultural resources through design flexibility. This flexibility involves the reduction of lot sizes in a development in exchange for setting aside the remainder of the property as significant amounts of natural, open space land. 25 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual In addition to allowing design flexibility, some experts argue that communities should mandate ambitious open space set asides as well. For example, to meet the definition of conservation design, a development would be required to have a certain percentage of the development site set aside as open space. The open space require- ment for conservation design would likely be higher than open space requirements elsewhere in the community. There are two approaches to mandating the open space percentage. The first is to look to the community plan to determine a reasonable set aside for a development site, based on the features and characteristics of the site. The second is to mandate a percentage open space for all developments. For convenience, both approaches are addressed in the model ordinance language. Residential Wastewater Treatment and Conservation Design Standard septic leach fields, particularly in areas of poor soils such as those in some areas of northeastern Illinois, require a relatively substantial amount of land in order to function properly and meet minimum spacing standards. Standard largeaot subdivisions have become the norm in order to meet the necessary requirements for wastewater disposal via standard septic leachfields, limiting the ability to conserve resources. For many areas in northeastern Illinois, the extension of public sewer facilities is not desirable or cost effective. Standard septic systems are in place and some alternatives are owned and operated by public agencies such as park systems. Small community wastewater alternatives treat wastewater near the location where it is generated, reducing the need for costly pipe networks and mechanical / chemical based solutions. There are several alternatives to the standard septic leach field that would permit more flexible project layouts. Some of them require less space; others serve several units at once, and can be located in common areas. Many of these alternatives are capable of reducing the environmental impact of wastewater disposal while meeting water quality standards. Although technology has produced system alternatives which would be effective in our region, critical issues regarding system design, ownership, management, and approval still need to be developed and clarified at the local, county, and state levels. For the purposes of conservation design practices, the most useful technologies for small scale sewage treatment facilities are those that perform effectively with the minimum amount of necessary attention. The low-maintenance, alternative systems available rely on biological rather than highly mechanized or chemical treatment, followed by various forms of land application. Cost is often greater than the standard septic leach field but higher treatment standards can be achieved, which increases the environmental quality of a project with regard to water resources. A detailed discussion of these alternative wastewater treatment strategies is beyond the scope of this project. For more information, coordinate with the local health department, or see N IPC's publication Protecting N ature in Your Community (Chapter 7). (The bulk of the material in this discussion of wastewater treatment was adapted from material prepared by the Countryside Program. (http://www.countrysideprogram.org)) Model Ordinance Language The following model ordinance language can be adapted to modify existing local codes and ordinances. Blanks and bracketed ([ ]) sections should be filled in with language appropriate for each community. 26 Chapter 4 Principles And Practices For Conservation Design Model Ordinance Language Commentary (Adapted from the Countryside Program) The amount of natural area that can realistically be set aside is related to the density and type of units per- mitted. The higher the density, the more difficult it is to achieve a large percentage of natural areas unless sufficient flexibility is available in terms of dwelling types and setback requirements (i.e., allowing attached single-family units). It also should be noted that a minimum open space requirement may not be appropriate in all zones. In residential zones with low to moderate density, the requirement will likely be helpful. In commercial zones or zones with intention- ally high residential density, an open space require- 6ther ment may constitute enforced sprawl. Two options are A 1. The minimum open space / natural area for a give below for addressing the open space require- given development shall be determined by ment. looking to the community comprehensive plan to determine existing standards for open space. The first option assumes that flexible lot design will lead to open space set asides without a mandated percent- age. In order to create a truly noticeable difference between a standard subdivision and a conservation design, in no case should the open space requirement be less than is required in similar zones elsewhere in the community. Beyond this guideline, this option assumes that no restriction is necessary since natural areas will naturally expand as lot sizes are reduced and other conservation design practices are introduced. This option is preferred for nonresidential zones. Or A 2. At least % of the development shall be If a mandated open space percentage is selected, the set aside as natural area / open space. (See community must decide the appropriate percentage. recommended requirements in commentary.) This may vary by residential zone, and is recom- The natural area counted toward this set-aside mended for residential areas only. Some examples of shall not include parkways, landscape islands, recommended percentages are given below. or similar features and should meet the definition of natural area given in [Appendix A]. The Kane County's 2020 Land Resource Management natural area set-aside shall not include wetlands, Ran (p. 79) calls for the preservation of 40% open floodplains, or other inherently unbuildable space in all new development. areas. Lake County's Unified Development Ordinance (http://www.co.lake.il.us/ elibrary/ ordinances/ plan- ning/ Complete UDO.PDF) requires 30% in most res- idential zones, and 40%in zoneswith .45 du/acre or lower density. 27 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Model Ordinance Language (continued) Commentary Will County's Land Resource Management Ran (http://www.willcountyland use.corry Irmp/Irmpmain.html) sets an overall goal of 20% of the land in the county being set aside as open space. B. The real property described herein must be maintained in perpetuity for[tailor to local purpose] Language should be included to restrict future devel- only and shall not be improved with any building, opment of the open space, to ensure that the open structure, or appurtenant facility. This restriction space remains undeveloped in perpetuity. shall run with the land and be binding on successors and assigns of Grantee. Lot size restrictions are eliminated completely to make way for creative design solutions. C. No minimum or maximum lot size shall be imposed. Each municipality or county must establish the precise density for conservation design based on the prevail- D. The maximum density shall be that of the underlying ing characteristics in the municipality or county. or pre-existing zoning, in dwelling units per acre. Normally, this will be the net density of the zoning dis- trict now in place in the areas where conservation E The maximum number of dwelling units permitted in design is desired. The net density of a subdivision is a conservation development shall be calculated by: usually lower than the gross density (which is derived from the minimum lot area divided by one acre or 1. Deducting the following from the total project 43,560 square feet) because of land area devoted to area: roads and the fact that some of the lots are larger than the minimum required. (A detailed discussion of the a. Any public right-0f-way within the project distinctions between the net density and the gross den- boundary existing at the time the development sity is included in Appendix B, Determining the plan is submitted; and Allowable Density for Conservation Design.) b. The area of land within a floodplain, designated One of the principles of conservation design is to be wetland, or existing waterbody that exceeds density neutral when comparing the number of poten- the minimum acreage required for restricted tial units under conservation design to the number of open space (if such a requirement exists). potential units under conventional development. Where floodplains and wetlands overlap, However, it is recognized that floodplains, wetlands, they shall be counted only once. and waterbodies are natural features that affect the development capacity of a site. At the same time, it is 2. Multiplying the result of Subsection 1 by the possible that in a standard subdivision, especially a maximum density permitted per acre as set forth larger lot subdivision, much of the area within flood- in this Section above. plains, wetlands and smaller ponds could be included in the rear yards of individual lots, thereby not reduc- ing or only moderately reducing the overall develop- ment capacity of the site. Therefore, the Model rec- ommends that there be a reduction in density for proj- ects that are substantially impacted by floodways, wet- lands, and/or waterbodies. When the area of these key environmental open space components exceeds the number of open space acres that are required to 28 Chapter 4 Principles And Practices For Conservation Design Model Ordinance Language (continued) Commentary be set aside, the acreage that is in excess of the open space requirement is to be deducted from the total project area, and the density is to be based on the net area. (See Appendix B for an example of how this deduction is calculated.)Additional natural resource characteristics (i.e. steep slopes, prime farmland, drainage courses outside designated floodways, etc.) could also be deducted depending on the priorities of the community. 3. Development incentives may be granted at the See Appendix C, Conservation Design Incentives, for discretion of the community. a detailed discussion of development incentives and when they are appropriate. 29 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Practice 2: Arranging the Development Ste Maintain critical natural areas by designing the site with sensitivity. Group buildable lots together to maximize the area of undisturbed land. How should the buildable lots be arranged on a development site?The process of laying out lots, roads, and nat- ural areas is one of the most important aspects of conservation design. Conservation design advocates for a sen- sitive approach to the landscape, an approach which treats each development site as a unique challenge to be approached with the complementary goals of developing the maximum allowable number of lots AND conserv- ing natural lands and processes to the greatest possible extent. (Note: This practice is most applicable to large development sites on previously undeveloped land. However, even on smaller development sites or sites which have existing development, the basic strategy of seeking to conserve and restore the most valuable natural resource areas can be employed.) Each community will benefit from a comprehensive planning process that identifies and maps the natural features of the community. With such an inventory in place, the community can quickly identify whether proposed devel- opments meet community conservation goals. Comprehensive planning is discussed briefly in Chapter 3. More in depth information about community comprehensive planning can be found in N IPC's Environmental Considerations in Comprehensive Ranning and R-otecting Nature in Your Community. These publications provide detailed practical advice for updating the community comprehensive plan to include environmental considera- tions. Copies are available from N IFC's publications department; call (312) 454-0400 with inquiries. R-otecting N ature is also available on the web at http://www.nipc.cog.il.us/ protecting 2001 0/620.htm. Randall Arendt, a national expert in conservation design, outlines the following four step process for arranging the development site (Arendt 1996). 1. Identify all Pbtential Conservation Areas. This will include all inherently unbuildable areas (floodplains, wetlands, steep slopes) and also buildable areas that are sensitive environmentally (natural areas, stream and wetland buffer areas, woodlands, etc.), significant historically and culturally, or important for conservation for some other reason. The developer will be responsible for identifying the conservation areas; a community resource inventory or comprehensive plan can be a valuable tool in monitoring the protection of conservation areas. 2. Locate the House (or other building) Sites. At this point, only the specific sites for buildings to be constructed should be located. To maximize the revenue potential of the sites, the developer will take care to locate the sites to maximize views and access to natural areas and other amenities. 3. Design the Street and Trail Systems. Determine how to most efficiently lay out the street system to access every home. Similarly, homes should have easy access to walkways and trail systems within the development. 4. Draw in the Lot Lines. This is the final step and should be almost trivial once the building sites and street system have been identified. For a more in depth discussion of Arendt's suggested design process, refer to Conservation Design for Subdivisions, pages 41-48. 30 Chapter 4 Principles And Practices For Conservation Design Although not explicitly stated in Arendt's model, an important characteristic of nearly any conservation develop- ment is the grouping of building sites. Certainly, grouping alone does not lead to conservation. It is an important element, however, of most conservation developments, and should result naturally from the employment of Arendt's design process. Grouping the buildings together allows for the creation of contiguous natural areas. Grouping also ensures the development of compact neighborhoods that are amenable to walking, cycling, and interaction between neighbors. Model Ordinance Language The following model ordinance language can be adapted to modify existing local codes and ordinances. Blanks and bracketed ([ ]) sections should be filled in with language appropriate for each community. 31 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Model Ordinance Language Commentary (Adapted from UW Extension Model Ordinance) A. Lots and buildings should be grouped. B. Groups should be located to minimize negative impacts on the natural, scenic, and cultural resources of the site and conflicts between incompatible uses. C.Groups should avoid encroaching on rare plant communities, high quality habitats, or endangered species identified by the Illinois Department of N atural Fesources. D.Whenever possible, open space should connect with existing or potential open space lands on adjoining parcels and local or regional recreational trails. E Groups should be sited to achieve the following goals 1. Minimize disturbance to woodlands, wetlands, grasslands, mature trees, and steep slopes. 2. Prevent downstream impacts due to runoff through adequate on-site storm water management p ra cti ces. 3. Protect scenic views of open land from adjacent roads. Visual impact should be minimized through use of landscaping or other features. 4. Protect archaeological sites and existing historic buildings or incorporate them through adaptive reuse. 5. Encourage sense of community. 6. Minimize impacts to prime farmland soils and large tracts of land in agricultural use, and avoid interference with normal agricultural practices. F. Landscaping around the building group may be necessary to reduce off site views of buildings. Landscaping around the group should utilize native plant species, ideally based on pre-settlement vegetation communities found on the site. 32 Chapter 4 Principles And Practices For Conservation Design Practice 3: Building Setbacks Biminate setback requirements for the interior of development sites while maintaining expectations on the perimeter. Conventional ordinances generally require large setback distances between homes and adjacent homes, streets, and lot lines. In order to meet conventional requirements, lots must be of substantial size, where the house is locat- ed at the center with generous spaces on all sides. Conservation design discourages this approach to configuring homes and lots. Rather than having large front, back and side yards for individual homes, conservation design calls for smaller yards in exchange for larger expanses of contiguous natural areas. To accomplish this, most setback requirements must be substantially reduced or eliminated. The ordinance language offered here differentiates between requirements for the perimeter of the development site and requirements for the interior of the site or individual lots. In general, it is recommended that the perime- ter of the site be developed in such a way that consistency with surrounding development is maximized. For most communities, a priority in approving new development is to minimize complaints or opposition from existing res- idents and neighbors. By developing conservation sites with sensitive perimeter setbacks, context is respected and conflict with neighboring developments is reduced. In contrast, setback requirements for the interior of the development site can be extremely permissive. This model ordinance recommends eliminating minimum lot sizes altogether, allowing for creative solutions to site design such as condominium arrangements where the entire site is commonly owned. Further, because existing building codes address health and safety requirements for the spacing between buildings, it is not necessary to address this spac- ing in the zoning ordinance. In fact, setback requirements in conventional zoning ordinances often serve to enforce largeaot developments which are built in opposition to many conservation design principles. Model Ordinance Language The following model ordinance language can be adapted to modify existing local codes and ordinances. Blanks and bracketed ([ ]) sections should be filled in with language appropriate for each community. 33 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Model Ordinance Language Commentary (Adapted from the Countryside Program) Buildings, structures, pavement, and streets shall be located in compliance with the following development and site planning standards. A. Lot Requirements 1. Dwelling units are not required to be on lots. A key to successful conservation design is flexibility in However, when lots for standard detached area and yard standards. If the municipality or county single-family dwellings or sublots for single-family chooses to include minimum lot and yard standards, suf- group or attached dwelling units are included as ficient reductions from the existing lot area, width, and part of a conservation development, such lots or yard requirements must be made in order to achieve sublots shall be of sufficient size and shape to goals of conservation design. If lots are not used, build- accommodate dwelling units in compliance with ings will be managed condominium style, where own- the spacing requirements of this section. ers own the building but not the underlying land. B. Perimeter Building Regulations Perimeter Setback: The perimeter regulations apply to the exterior boundary (the perimeter) of the develop- 1. The minimum setback from an existing public ment site. street shall be that which is previously estab- lished in the zoning ordinance or subdivision The setback from existing public streets AT THE regulations. PERIMETER OF THE SITE should be the same as the front yard setback in the standard single-family district zoning regulations (to maintain consistency). Acceptance of conservation design is increased when expectations are maintained on the perimeter. 2. The minimum setback from the project boundary Similar to setbacks from existing streets, setbacks from shall be that which is previously established in the project boundary should maintain the status quo the zoning ordinance or subdivision regulations. established by subdivision regulations and existing development. C. Interior Building Setback/Spacing Regulations Interior Setback: The interior setback requirements apply to setbacks from streets, lot lines(if using), and other buildings on the INTERIOR of the development site (as opposed to on the perimeter). 1. Interior setbacks are left to the discretion of the The municipality or county is encouraged to eliminate developer, but must meet all existing building interior setback or separation requirements above and and fire code requirements. beyond building and fire code requirements. However, it is also recommended that any approvable development plan be required to indicate what those setbacks and separations will be. 34 Chapter 4 Principles And Practices For Conservation Design Principle B. Protect and Create Natural Landscapes and Drainage Systems Facilitating conservation design and fostering stewardship of natural areas and natural communities is critical to achieving regional biodiversity goals. Discussion The northeastern Illinois landscape has been dramatically transformed from its original pre-settlement form to be made suitable for agriculture. Today a great deal of new construction involves the conversion of former agricul- tural lands into residential subdivisions and commercial areas. If the land is still fertile and active in production, there may be great value in maintaining its current condition. A second vital consideration is the restoration of the natural landscape, and/or preservation of natural landscape remnants through conscientious design practices. Conservation design facilitates these practices to a far greater degree than conventional development due to the amount and contiguous nature of the natural resource areas potentially preserved. As the primary decision makers on land development, local officials and staff can play a lead role in the conser- vation and restoration of natural areas and landscapes. Facilitating conservation design and fostering steward- ship of natural areas and natural communities, which are the foundation of the region's environmental health, is critical to achieving the short and long term goals outlined in the regionally adopted Biodiversity Fbcovery Plan. The overall goal of this Ran is "to protect the natural communities of the Chicago region and to restore them to long-term viability, in order to enrich the quality of life of its citizens and to contribute to the preservation of glob- al biodiversity." Benefits, Examples, and Resources Protecting and creating natural landscapes and drainage systems can be beneficial to the local community, future homeowners, and the developer of the site. See Chapter 2 for a full discussion of the economic benefits of this principle. Community Benefits • Feduces flooding and stormwater management costs. • Feduces long-term maintenance costs. Homeowner Benefits • Increases property values. • Decreases maintenance costs. Developer Benefits • Feduces landscaping and other installation costs. • Enhances marketing potential. 35 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Results of a study conducted in 1994 for the real estate industry showed that 77.7 per cent of all home buyers and shoppers in the study rated natural open space as either "essential" or "very important' in planned commu- nities. Walking and bicycling paths ranked third. A research spokesperson noted that consumers are increasing- ly putting a higher premium on interaction with the environment through inclusion of natural, open space and nature paths. These findings differ greatly from the 1980's preferences, which included tennis courts, swimming pools, and golf courses(San Francisco Chronicle, January 8, 1995). From: "Economic Impacts of Protecting Rivers, Trails and Greenway Corridors" National Park Service, 1995, Washington DC page 1-3 Additional Fbsources Chicago Wilderness. 1999. Biodiversity Recovery Plan. Chicago. Chicago Wilderness. 1999. An Atlas of Biodiversity. Chicago. The Conservation Foundation website: http://www.theconservationfoundation.org. Diehl, J. and T. Barrett. 1988. The Conservation Easement Handbook. Washington DC: Washington D.C: Land Trust Alliance. Northeastern Illinois Planning Commission. 2000. Protecting Nature in Your Community. Chicago. Northeastern Illinois Planning Commission. 1997b. Natural Landscaping for Public Officials: A Source Book. Chicago. Northeastern Illinois Planning Commission. 1997c. Northeastern Illinois F;bgional Greenways and Trails Plan. Chicago. USDA-Natural Resource Conservation Service, Illinois Environmental Protection Agency. 2002. Illinois Urban Manual: A Technical Manual Designed for Urban Ecosystem Protection and Enhancement. http://www.il/ nres.usda.gov/engineer/ UrbManBro.html, Champaign. United States Environmental Protection Agency. 2002b. Weedlaws. http://www.epa.gov/grtlakes/greenacres/weedlaws United States Environmental Protection Agency. 2002c. Landscaping with Native Plants, Wild Ones Handbook, Landscaping with Native Plants, and Great Lakes Plants. http://www.epa.gov/qrtlakes 36 Chapter 4 Principles And Practices For Conservation Design Practice 4: Natural Area Protection and Resource Conservation Update ordinances to substantially restrict development on or near natural areas, and require or encourage unde- veloped buffers around these areas. Conservation design encourages the dedication of open space on a site that will protect and restore natural areas and resources, and provide for passive recreation where appropriate. Through a conscientious site design process, the development can be configured to maximize the areas that are protected and conserved. Fbssible areas to evaluate for protection include hydric soils, streams, lakes, wetlands, floodplains, steep slopes, significant wildlife habitats, remnant prairies, woodlands, farmland, and sensitive aquifers and their recharge areas(Arendt 1996). Certain sensitive areas, including floodways, flood fringes, non-isolated wetlands, isolated wetlands, and threatened and endangered species habitats may be protected by federal, state, and local statute, but each community must decide the extent to which it will protect natural areas that do not benefit from legal pro- tection. Natural area buffers are an important strategy for protecting sensitive natural areas. The model ordinance lan- guage given in this section enables the use of buffers around natural areas. The following list enumerates several benefits resulting from the use of buffers: • Slows water runoff. • Removes up to 50%or more of nutrients and pesticides in runoff. • Fbmoves up to 60%or more of pathogens in runoff. • Fbmoves up to 75%or more of sediment in runoff. • Fbduces noise and odor. • Serves as a source of food, nesting cover, and shelter for wildlife. • Stabilizes streambanks and reduce water temperature in stream. • Reduce downstream flooding. Greenways, or linear corridors of green, can function to preserve natural resources and in some cases define or link a trail system. Linking and providing connections to existing and proposed trails and greenways provides additional benefits to natural resource protection. Existing local greenways may be protected by municipal, park, forest preserve, or conservation districts, and county transportation departments. Regional, state, and federal greenways and trails are documented in N IPC's 1997 Northeastern Illinois Regional Greenways and Trails Flan map. Communities also may decide to include significant historic and cultural assets in designated open space areas. Through the comprehensive planning process, communities will determine which of these areas are most relevant and important for conservation. Model Ordinance Language The following model ordinance language can be adapted to modify existing local codes and ordinances. Blanks and bracketed ([ ]) sections should be filled in with language appropriate for each community. 37 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Model Ordinance Language Commentary Natural Area and Buffer Protection and Conservation The [Municipality or County] recognizes the ecologi- cal, geological, educational, scenic, economic, and aesthetic importance of preserving natural areas in public or private ownership. A natural area is an area The natural area definition is partly adapted from the of land, not necessarily undisturbed, which either "Illinois Natural Areas Preservation Act' (525 ILCS retains or has been substantially restored to its original 30/3.10). The act establishes state policy to protect natural or native character. and maintain a register of natural areas and buffer areas, provides certain forms of protection and con- trol, and encourages and assists in the preservation of natural areas and features. The [Municipality or County] recognizes the impor- Selected language on buffers, buffer widths, and tance of buffers that preserve, provide access to, or buffer averaging is adapted from the Kane County otherwise serve as necessary adjuncts to natural areas Code. (hftp://www.co.kane.il.u§) by protecting streams, lakes, and wetlands. Buffers include, but are not limited to, areas of predominant- ly deeply rooted native vegetated land adjacent to channels, wetlands, or lakes for the purpose of stabi- lizing banks, reducing contaminants including sedi- ments in storm water that flows to such areas. The function of the buffer is to create a transition to the Strategically placed buffer strips in the landscape can area targeted for protection. The buffer absorbs and effectively mitigate the movement of sediment, nutri- withstands the impact of harming activity. For this rea- ents, pesticides, and other pollutants. son, the ongoing healthy function of the buffer must be assured. Accordingly, the harmful activity cannot be allowed to overpower the buffer. Natural areas and buffers shall be preserved on the site, including, without limitation, native vegetation, wetlands, natural floodplain storage, or other valuable environmental and biological resources. A.An area designated for natural area and buffer protection purposes may be: 1. preserved or restored to its natural state, 2. designed and intended for the passive use and/ or enjoyment of residents of the proposed development, or 38 Chapter 4 Principles And Practices For Conservation Design Model Ordinance Language (continued) Commentary 3. preserved in order to expand and extend the usefulness of existing preserved open space and natural areas. B. Dedicated buffers and natural areas shall be designed and located to conserve significant natural features located on the site. C. Dedicated natural areas shall be interconnected Greenways, or linear corridors of green, can function with open space areas, greenways, and trails on to preserve natural resources and in some cases abutting parcels where possible and appropriate. define or link a trail system. linking and providing connections to existing and proposed greenways and trails provides additional benefits to natural resource protection. Existing local greenways may be protected by municipal, park, forest preserve, or conservation districts, and county transportation departments. Regional, state, and federal greenways and trails are documented in NIPC's 1997 Northeastern Illinois Regional Greenways and Trails Plan map. 39 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Practice 5: Land Compatible Design Encourage developers to design sites to fit the topography, features, and soils of the natural landscape. Excess stormwater runoff, and the resultant flooding and erosion, arise from development and alteration of the natural landscape. For this reason, it is highly desirable to preserve or restore features of the natural, pre-devel- opment landscape whenever possible. Careful consideration of the pre-development landscape can vastly improve the drainage and stormwater runoff performance of a development. On sites that have been altered through grading, engineered drainage systems, and agricultural conversions, developers should be encouraged to study the original landscape and design the landscape using the original as a guide. On sites that have not been substantially altered from their natural form, developers should be encour- aged to preserve this form. Generally, substantial alteration of the existing site landscape is discouraged. Special consideration should be given, however, to proposals which seek to restore a site to its original natural form through careful and consci- entious study. Fbstoration of the natural landscape will not be appropriate in all cases, but should be permitted unless there is a compelling agricultural or ecological reason to avoid it. Much of the language pertaining to natural landscape sensitivity may be currently addressed in other existing reg- ulations. If not, N IPC's model ordinances for Soil Erosion and Sedimentation Control, Stormwater Management, and Streams, Lakes, and Wetlands R-otection will be of assistance in developing language for an ordinance. (Full citations for these documents are given in the bibliography. To obtain copies, contact N IPC's publications depart- ment, (312)454-0400.) Model Ordinance Language The model ordinance language given in this section is adapted from the City of N apa Valley, California, Rparian Habitat Areas section of their ordinance. It can be adapted to modify existing local codes and ordinances to require land compatible design for all developments or for conservation developments only. Blanks and bracket- ed ([ ]) sections should be filled in with language appropriate for each community. 40 Chapter 4 Principles And Practices For Conservation Design Model Ordinance Language Commentary The [Municipality or County] recognizes that natural drainage patterns, native vegetation, and stabilization of soil during construction are important factors in the prevention of flooding and degradation of water qual- ity. Priority shall be placed on site design that main- tains natural drainage patterns and watercourses. Alterations to natural drainage patterns shall not cre- ate flooding or degradation in water quality for adja- cent or downstream property. A natural landscape sensitivity plan (NLS) must be prepared to insure pro- tection of the natural contours and vegetation on a development site. A.A natural landscape sensitivity plan (N LS) shall address the following requirements: 1. Site development shall be fitted to the topography and soil so as to create the least potential for vegetation loss and site disturbance; 2. Vegetation removal shall be limited to that amount necessary for the development of the site; 3. Vegetation native to the site or plant community shall be restored in areas affected by construction activities. Temporary vegetation, sufficient to stabilize the soil, may be required on all disturbed areas as needed to prevent soil erosion. New planting shall be given sufficient water, fertilizer if necessary, and protein to ensure reestablishment. 4. Site design shall minimize the disturbance and loss of vegetation. 41 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Model Ordinance Language (continued) Commentary B. A natural landscape sensitivity plan shall be drawn to scale and shall be of sufficient clarity to indicate the nature and extent of the work and restoration efforts proposed. An N LS plan shall include the following information: 1. Existing contours of the site, as well as finished The Illinois Urban Manual provides detailed information contours to be achieved by grading. Contours and direction on sound planning procedures and prin- shall be sufficiently detailed to define the ciples for more than 40 conservation practices topography over the entire site; designed to reduce erosion and address water quality and stormwater management problems. Technical 2. Delineation of areas to be cleared during specialists can assist in the development of soil erosion development activities; and sediment control, stormwater management, and natural area protection plans. (USDA Natural 3. Restoration of vegetation proposed for all Resources Conservation Service and Illinois surfaces to be exposed during development Environmental Rotection Agency's Illinois Urban activities, including any dredged, filled, or graded Manual is available onaine aswell in document form at areas; http://www.il.nres.usda.gov/ engineer/ UrbManBro. html ) 4. The location and extent of natural area buffers and method of implementation; any use restrictions and method of implementation. C.All approved measures to mitigate the loss or impact to the natural landscape shall become conditions for approval of the project. In addition all approved N LS measures shall be carried out prior to final issuance of the building permit or con- currently with the installation of site improvements in the case of a final plat of subdivision. D. The planning director may waive some or all of the requirement for projects which will not result in disturbance to the land or where on-site conditions clearly demonstrate that the site would not effectively respond to revegetation. E The NLS must be approved by the Municipal Engineer (or equivalent). 42 Chapter 4 Principles And Practices For Conservation Design Practice 6: Natural Landscaping Update landscaping ordinances to encourage the use of plant materials native to northeastern Illinois. Require nat- ural landscaping in and around stormwater facilities, wetlands, lakes, and streams. Natural landscaping is the design, construction, and maintenance of landscapes that provide the beneficial nat- ural functions that are lost through installation of conventional lawns or agriculture. Natural landscaping stresses the preservation and reintroduction of plants native to our area. The native plants used in natural landscaping are hardy and attractive. They can be used to stabilize soil, reduce flooding, absorb pollutants, and sustain wildlife (N IPC, 1997b). Native landscaping has been defined as the use of plants—for example, prairie, woodland and wetland plants-that flourished in northeastern Illinois prior to settlement. Natural landscaping isa more popular and broad- er concept because it implies the use of native plants but also suggests landscaping to give the"look" of the land- scape that existed before the mid-1880s. In addition, there also may be an attempt to restore or reconstruct the landscape to look and function more as it did before settlers, other than Native Americans, lived here. Presently, the predominant landscaping material of the Chicago region is the turf grass lawn. The lawn is bor- rowed from the heavily grazed, short grass pastures and formal gardens of Europe, and provides aesthetic appeal and recreational space. This modern landscape contrasts sharply with the predominant landscape prior to European settlement. Then, prairies were interspersed with woodlands, savannas, and wetlands. Hundreds of species of plants could be found on every acre of land. W hile interest is growing in natural landscaping, in many communities the conventional turf grass landscape has been virtually mandated by local weed and landscaping ordinances. In these circumstances, the first step is to revise the local ordinances to allow natural landscaping (N IPC, 2000). Natural landscapes are not a threat to safety or pub- lic health. In fact, enforcement of weed ordinances against natural landscapes increases wind-borne Perception allergenic pollen and other health hazards. For exam- Native vegetation may harbor undesirable ple, ragweed thrives in disturbed soil recently devel- wildlife and insects. oped or degraded. Perennial native plants and native grasses are generally not producers of wind-borne Fact allergenic pollen. By contrast, the chemicals used to In a 1988 survey of wildlife acceptance, some maintain a turf lawn pose health risks, such as harm- 65% of the adult population reported that the ful level of nitrate in drinking water (,bhn Marshall enjoyed seeing or hearing wildlife while pursu- Law Review). ing other activities around the home. To allow natural landscaping, a city or village should Fact examine their local weed and/or landscaping laws Natural vegetation does not provide a steady and create, add to, or amend the language to ensure supply of the sort of food required to sustain a that natural landscaping is not prohibited. population of vermin. Figure 6, below shows the root system of native (From Better Site Design) plants, which can be up to ten feet deep, in contrast to the root system of turf grass, which is only a few inches deep. 43 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual h - 1 I -akm. low E��" III ;•I' .s' � r'••-�� ' I �": i 7 1� I s i J I h Figure 6: Fbot Systems of Native Rants(Conservation Fbsearch Institute, Heidi Natura, 1995) Model Ordinance Language The following language is adapted from the proposed natural landscape ordinance from the National Wildflower Fbsearch Center in Austin, Texas (as reprinted in N IPC's Natural Landscaping for Public Officials). It provides a broad legislative purpose to support natural landscaping and then establishes the right to landscape naturally, and can be adapted to modify existing local codes and ordinances. Blanks and bracketed ([ ])sections should be filled in with language appropriate for each community. 44 Chapter 4 Principles And Practices For Conservation Design Model Ordinance Language Commentary A. Frights of Landowners to Pursue Natural Landscaping In addition to weed and landscaping laws, ordi- nances that relate to tree preservation, fire codes, and 1. Within the [municipality or county], the use of pest control should be examined for compatibility. natural plant materials for landscaping is permitted. Section A permits the use of natural landscaping mate- 2. The [municipality or county] recognizes the rials within the municipality or county. importance of the preservation and restoration of natural plant communities, and encourages the protection and enhancement of these communities within its boundaries. B. Establishment of Native Vegetation for Ra-source Section B acknowledges the importance of native veg- Protection in New Development etation in the protection of natural resources, preven- tion of flooding, and quality and quantity of water 1. New development must include establishment of resources, and requires the use of native vegetation vegetation using the Native Rant Guide for under some circumstances. Streamsand Stormwater Facilitiesin Northeastern Illinois, N FUS, et al., (as amended)as a minimum standard for: a. drainage swales, b. perimeters of detention basins, and c. edges of streams, lakes, and wetlands. 2. In addition, natural landscaping is encouraged in other areas such as common areas. C.A landscape plan should be submitted with the final plat of subdivision 45 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Practice 7: Natural Area Management Require dear specification of how natural areas will be managed, and designate a legal entity responsible for maintenance for all natural areas. Ranning for open space and natural resource protection in conservation design must include short and long term management for both routine and remedial maintenance. The maintenance responsibility should be detailed as part of an agreement between the property owner or the homeowner's association and the local government so that the local government has a record of who is liable for such maintenance. Such an agreement should be incor- porated into the approval of a development. There are four approaches to managing natural areas. 1. The natural area may be dedicated to the municipality or county, or another public agency such as a park district, forest preserve, or conservation district. 2. A homeowners association may take possession of the natural area. 3. A conservation easement can be granted to the government (local, state or federal) or to a not-for-profit whose primary purpose is in keeping with conservation development and design, such as the Nature Conservancy. The benefits of a conservation easement are its flexibility, the potential for income tax reduction, estate tax reduction, and property tax reduction for homeowners. A sample conservation easement agreement is available; contact N IPC to obtain a copy. 4. The natural area may remain in the private ownership of the developer or another entity. If a public agency is designated to own and/or manage the dedicated natural area, it may be necessary to levy a special tax to support management and maintenance. This has been done in Kane County, Illinois through the use of a Special Service Area (SSA) designation. Even in cases where the natural area remains in private own- ership or is owned by the homeowners association, the municipality or county may wish to establish a backup SSA to provide funding if the owning entity cannot properly manage the natural area over time. (See Appendix D, Special Service Area Financing, for more information on this funding strategy.) Model language from the Kane County ordinance is included in the second part of the model ordinance text that follows. Model Ordinance Language The following model ordinance language can be adapted to modify existing local codes and ordinances. Blanks and bracketed ([ ]) sections should be filled in with language appropriate for each community. 46 Chapter 4 Principles And Practices For Conservation Design Model Ordinance Language Commentary (Adapted from the Countryside Rogram) A. Ownership and Management of Dedicated Natural Areas Natural areas in a conservation development may be owned by the municipality or county, and asso- ciation, a land trust or other conservation organi- zation recognized by the municipality or county, or by a similar entity, or may remain in private own- ership. 1. Public Ownership and Management. The munic- ipality or county may, but shall not be required to, accept dedication in the form of fee simple ownership of the designated natural area. 2. Homeowners Associations. Restricted natural areas may be held in common ownership by a Homeowners' Association, Community Association, or other similar legal entity, or the individual members of a Condominium Association as ten- antsin-common. The municipality or county's legal advisor shall determine that, based on documents submitted with the development plan, the association's bylaws or code of regulations specify the following requirements: a. Membership in the Association shall be mandatory for all purchasers of lots in the development or units in the condominium. b.The Association shall be responsible for main- tenance, control, and insurance of common areas, including the dedicated natural areas. 3. Creation of Conservation Easements. A proper- A sample conservation easement agreement is avail- ty owner can create a conservation easement able; contact N IPC to obtain a copy. restricting the use of property to protect or pre- serve its natural features. If the property owner chooses to grant a conservation easement to [the unit of local government], [the unit of local government] can accept this grant provided that: 47 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Model Ordinance Language (continued) Commentary a.The provisions of the conservation easement are acceptable to the municipality or county; and b. Continuing maintenance and management responsibilities are established. 4.Private Ownership of Dedicated Natural Areas. Dedicated natural areas may be retained in ownership by the applicant or may be trans- ferred to other private parties. B. Public Management of Dedicated Natural Areas. If a public agency will manage a common natural This language is adapted from Kane County, Illinois area, either by designation or necessity, a funding Special Service Area ordinance. (hftp://www. procedure may be established through the creation co.kane.il.us/ kccodes.htm) of a Special Service Area ordinance to cover the costs of maintenance. The ordinance authorizes the levy of taxes to pay the costs of providing the required services. 1.Purpose The purpose of establishing the Special Service Area is to provide services to a desig- nated area of the [local government] (the "Area") including the operation, maintenance, repair, rehabilitation, replacement, restoration and reconstruction of any site runoff storage area, drainage way, ditch, swale, storm sewer, other stormwater facility, or natural areas; relat- ed administrative costs; permit fees; public lia- bility insurance; other consulting services includ- ing but not limited to the costs of design, engi- neering, surveying, landscaping and legal serv- ices(collectively, the "Services"). 48 Chapter 4 Principles And Practices For Conservation Design Model Ordinance Language (continued) Commentary 2.Provisions a.authorization to levy or impose additional taxes upon Areas for provision of Services; b.that the area will benefit specially from the Services to be provided by the [local govern- ment] and the Services are unique; c. that the cost of providing the Services shall be paid by the levy of a direct annual ad val- orem tax upon all taxable property within the Area; d.that the procedure calling for public hearing and objection petition is followed according to Illinois law governing special service area tax. 49 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Principle C. Fbduce Impervious Surface Areas Fbducing the impervious cover in new developments can substantially improve on-site stormwater management, leading to improved water quality. Discussion Impervious Cover: Any surface in the urban landscape that cannot effectively absorb or infiltrate rainfall (CW P Better Site Design). Impervious cover(also called impervious surface)includes roads, parking lots, sidewalks, swimming pools, roof tops, garages, patios, and any other surfaces through which water cannot pass. This section argues for an overall reduc- tion of impervious surface area. However, imperviousness varies by development type. While there may be simple ways to reduce impervious cover in larger-lot residential developments, denser residential areas and commercial areas will have a higher percentage of impervious cover, and it will be difficult, or even counterproductive, to reduce this in many cases. A densely developed area with a high percentage of imperviousness may protect natural areas in another location. For these reasons, it is essential to consider impervious surface area reduction goals within the context of the development type. When land is developed, the surface of the land often is transformed from natural cover to impervious cover. This transformation adversely impacts the natural environment, especially natural water resources. Fbinfall that was ini- tially absorbed by the landscape can no longer be absorbed. The excess water becomes stormwater runoff, and, without adequate controls, this runoff causes increased flooding, channel erosion, and severe water pollution in downstream lakes and rivers. In Better Site Design, the Center for Watershed Protection gives a list of twenty "Impacts to Aquatic Resources Due to Impervious Cover." These effects start when the impervious cover is as low as ten percent. The effects include: • higher peak discharge rates and greater flooding, • lower stream flow during dry weather, • enlargement of the stream channel, • greater streambank erosion, • degradation of stream habitat structure, • greater loads of stormwater pollutants, • lower diversity of aquatic insects and freshwater mussels, • lower diversity of native fish species, and • decline in wetland plant and animal diversity. (See Better Site Design for complete list.) Just as rapid expansion of impervious cover leads to increased runoff and numerous adverse effects to the natural environment, reducing the impervious cover in new developments can substantially reduce runoff quantities and pol- lutant loads. The flexible lot design standards suggested in Principle B can reduce impervious cover. In addition, this section introduces alternative practices for road design, parking lot design, walkway design, and driveway design. Updating local codes to encourage or require designs with lower overall impervious cover is a direct and practical approach to pollution reduction, water resource protection, biodiversity support, and other conservation benefits. In addition to the substantial water quality and biodiversity benefits of impervious surface area reduction, there are substantial community and economic benefits to these practices. Increasingly, public officials, developers and neighborhood activists are viewing the streetscape—the external built environment of a development—as key determinants of neighborhood quality. Traditional 50 Chapter 4 Principles And Practices For Conservation Design Neighborhood Development(TN D)and New Urbanism are two visible movements in contemporary planning that advocate for narrower streets and reduced building setbacks. These movements value these design practices not for their benefits to the natural environment but for their community benefits—more intimate neighborhood settings with better pedestrian amenities(N IPC 1997a). Finally, the impervious surfaces of a new development: roads, sidewalks, and parking lots; are very expensive to con- struct. Fbducing the overall area of these features can translate into substantial savings for the developer. There are various ways to calculate these savings. Based on 1997 costs, N IPC's Reducing the Impacts of Urban R.anoff calcu- lates a savings of$910 per residence for reducing street width, sidewalk width, and driveway width in a new resi- dential development. Other savings, such as reduced construction time, shorter utility runs, and increased mar- ketability through improved aesthetics also can be considered, though these are more difficult to directly quantify. Benefits, Examples, and Resources As we have seen, updating standards and regulations Community Benefits for impervious surfaces can be beneficial to the local • Decreased demand for stormwater runoff community, future homeowners, and the developer of management. the site. See Chapter 2 for a full discussion of the eco- • Reduced municipal maintenance costs. nomic benefits of this principle. Homeowner Benefits • Increases biodiversity in nearby wetlands and Additional Resources water bodies. American Association of State Highway and • Proximity to neighbors increases chances of Transportation Officers. 2001. A Policy on Geometric friendly interaction. Design of Highways and Streets. Developer Benefits Center for Watershed Protection. 1998. Better Site • Decreased development costs. Design: A Handbook for Changing Development • Decreased development time. Bales in Your Community. Ellicott City, Maryland. Center for Watershed Protection, Stormwater Manager's Resource Center. 2002. Better Site Design Fact Sheet: Alternative Pavers. http://www.stormwatercenter.net. Center for Watershed Protection, Stormwater Manager's Fbsource Center. 2002. Stormwater Management Fact Sheet: Porous Pavement. hftp://www.stormwatercenter.net. Kulash, Walter M. 2001. Fbsidential Streets, 31 Edition. Urban Land Institute, National Association of Home Builders, American Society of Civil Engineers, Institute of Transportation Engineers. Northeastern Illinois Panning Commission. 1997a. Reducing the Impacts of Urban Ranoff: The Advantages of Alternative Site Design Approaches. Chicago. Green roof information Greenroofs.com. http://www.greenroofs.com/ . Pennsylvania State University. Center for Green Fbof Research web site. http:// hortweb.cas.psu.edu/ research/ greenroofcenter/about ctr.html. 51 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Practice 8: Ibadway Design Enact flexible standards for road length, width, right-of-way, and design. Require the minimum amount of paved surface area while maintaining safe and sufficient support of travel lanes, on-street parking, and emergency and support vehicle access. While streets and roadways often are viewed primarily as transportation facilities, conservation design recognizes that streets are a major element of the built environment. For this reason, conservation design seeks to maximize the functional effectiveness of roadways without overbuilding, and while considering the aesthetics of the street. Narrower streets not only reduce overall impervious surface area, leading to improved stormwater management, but also encourage slower traffic speeds which creates a safer and more livable street for residents. A 1998 study by Peter Swift concluded that "[There is] a clear relationship between accident frequency and street width and curva- ture. The findings support the theory that narrower ... streets are safer than standard width residential streets." Pbsidential Streets, Third Edition lists the following principles of roadway design: • Street planning should relate to overall community planning, including pedestrian and bicycle activity. • The street is an important component of the overall community design. Properly scaled and designed streets can create more attractive communities and can contribute to a clearly defined sense of place. • Wherever possible, street pavement layouts should be planned to avoid excessive stormwater runoff and to avoid heat buildup. • Streets can function socially such as meeting places and centers of community activity. • The overdesign of streets should be avoided. Excessive widths or undue concern with geometries Perception more appropriate for highways encourages The need for adequate turning radii for school greater vehicle speeds. buses and maintenance and emergency vehicles • Different streets have different functions and requires large cul-de-sacs. need to be designed accordingly. Blanket guidelines are inappropriate. Fact Fi re trucks with 30-4 0 foot turning radii are avail- The conservation design model naturally shortens able. road lengths by grouping developed areas where fea- sible. Care should be taken to carry on this natural Fact reduction of road area through the road design Many newer large service vehicles are being process. Minimizing paved surface area is important; made with tri-axles which allow for sharper turns. a second important consideration in roadway design is the conservation of scenic views and vistas. This is Fact especially relevant in rural, conservation development A smaller minimum turnaround radius of 30 feet communities. has been suggested by several organizations. The goal of a compact, pedestrian-friendly neighbor- Fact hood can be undermined if the typically wider road School buses do not typically enter cul-de-sacs. and right-0f-way standards of conventional suburban developments are used. As outlined in the introduc- (From Better site Design) tion to this section, wide streets are wide swaths of impervious cover and as such, also can contribute to excess stormwater runoff. 52 Chapter 4 Principles And Practices For Conservation Design The goal of narrowing and minimizing paved street area must be carefully balanced with basic requirements for health and safety. A common concern is that reduced street widths and rights-of-way result in reduced accessibil- ity for emergency vehicles, especially large fire trucks. The suggested widths and rights-0f-way given in the fol- lowing model ordinance language are adapted from Ibsidential Streets. This publication has the endorsement of the American Society of Civil Engineers, the Institute of Transportation Engineers, and the National Association of Home Builders and the suggestions are in compliance with the guidelines given by the American Association of State Highway and Transportation Officers (AASHTO) in the 2001 edition of A Fblicy on Geometric Design of Highways and Streets, commonly called the AASHTO Greenbook. Conventional developments generally include curb-and-gutter edging for new roads. Alternative edge construction and vegetated swales(see Ractice 10) are other ways not only to reduce overall imperviousness but also to sup- port the goals of impervious surface area reduction and improved stormwater management. Model Ordinance Language The following model ordinance language can be adapted to modify existing local codes and ordinances. Blanks and bracketed ([ ]) sections should be filled in with language appropriate for each community. 53 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Model Ordinance Language Commentary (Adapted from UW Extension Model Ordinance and Fesidential Streets) A. Neighborhood streets may take the form of a two- As described earlier, narrow streets often generate way street, a pair of one-way streets on either side safety concerns. By demonstrating ahead of time that of a landscaped median, or a one way loop street these basic requirements will be met, the developer around a small neighborhood green. Streets shall can work to allay these fears. be developed according to standards that promote road safety, assure adequate access for fire and rescue vehicles, and promote adequate vehicular circulation. B. The applicant must demonstrate by submitting a traffic study that access to the development has the capacity to handle traffic generated by the pro- posed project, and will not endanger the safety of the general public. C. Streets shall have the following design standards 1. Rght-0f-way widths. The right-of-way width for While collector streets may later need to be widened, each road shall not exceed the width of the residential streets should not require widening. street pavement specified in C.2 of this Section in addition to width for all public services includ- ing: drainage, sidewalks, bicycle trails, street trees, trails and walkways, utilities, snow stor- age, and grading. In residential developments, the right-0f-way width shall not provide an allowance for future widening. 2. Travel lane widths for local roads shall be deter- The widths given here are in compliance with the mined by the expected use and shall be within AASHTO Greenbook recommendations. In general, the following ranges: (F:bsidential Streets pp. 25- widening roads by a few additional feet does not 26) increase the capacity of the road, but it does encour- age higher driving speeds. 24-26 feet is adequate width for either parking on Recommended Pavement Widths both sides of the street with a single lane for traffic(i.e. one-way traffic flow, or where oncoming cars must Local Streets yield), or for parking on one side with two slow mov- No parking expected 16-18 feet ing traffic lanes. Fbstricted parking 22-24 feet Normal residential parking 24-26 feet Residential Collector Follow local standards 54 Chapter 4 Principles And Practices For Conservation Design Model Ordinance Language (continued) Commentary D. Additional Standards 1. Cul-de-sacs should be designed as semi-circular Connectivity is an important goal of residential street and circular loop roads. Minimum 30' outside design. Connected streets reduce overall vehicle trips radius around a landscaped island with a mini- by eliminating the need to backtrack. Connected mum 10' radius. The center landscaped areas streets also encourage and support pedestrian circu- should be depressed and potentially can be lation. However, connected streets also increase over- designed for stormwater storage. all impervious area. In residential street design a bal- ance must be found between impervious surface reduction and user-friendly design. With this balance in mind, this model recommends that the cul-de-sac, which generally does not encourage connectivity, should be used sparingly. Incorporating center land- scaped areas into the stormwater management scheme is a good way to offset the use of cul-de-sacs. Cul-de-sac design will require working with local emergency personnel for safe access to adjacent land uses. 2. Sidewalks shall have a maximum width of six (6) 6-foot sidewalks are most comfortable for pedestrian feet in high pedestrian traffic areas and a maxi- use. While narrower sidewalks may be adequate in mum width of five (5) feet in general pedestrian some circumstances, wider widths should be required traffic areas. Trails and other walkways with less in high traffic areas. pavement shall be encouraged where feasible. E Streets that serve as collectors, interconnecting sub- This model does not include recommendations for col- divisions and other major traffic generators, shall lector streets— however, the principles of building to be designed according to the [city/village/town/ minimum standards and reducing overall impervious- county]'s standards for collector roads. ness still should be observed. F. The developed area should have walkways on at For standard conservation design, the recommenda- least one side of the street. tion is to use walkways on one side only to reduce imperviousness. It is worth noting, however, that other systems such as Traditional Neighborhood Design call for sidewalks or walkways on both sides to encourage pedestrian flows. The decision about the use of walk- ways and sidewalks must be made in context with the development. G.The use of enclosed drainage curb and gutter sys- See Practice #10, Vegetated Swales, for more tems is discouraged in favor of vegetated swales, detailed information on the use of this practice. where feasible. 55 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Practice 9: Parking Lot Design Enact flexible standards for parking lot design in multi-family housing developments, commercial, and business areas. Require stormwater treatment for parking lot runoff using bioretention areas, filter strips, and/or other practices that can be integrated into required landscaping areas and traffic islands. There are several techniques that communities can use to reduce the volume and increase the quality of stormwa- ter generated at parking lots. These include: • Reducing minimum parking requirements to allow smaller lots to be built; • Allowing developers to use pervious materials for spillover parking; • Romoting the use of parking garages which expose less impervious cover to rainfall; and • Designing drainage and landscape systems that filter & infiltrate runoff. Adequate parking is a necessity for retail, commercial, and multi-family housing developments. The interpretation of `adequate' varies widely from community to community and project to project. In practice, parking lots are sometimes overbuilt and oversized due to municipal parking requirements and perceived demand. With a few simple modifications, parking requirements can be updated to discourage or prohibit overbuilding while still meet- ing actual demand for parking. These improvements can make a substantial reduction in impervious cover and as a result substantially reduce the negative impacts of runoff from parking lots. Communities commonly determine minimum parking ratios by either adopting and modifying the requirements of neighboring communities or by referring to informational publication by the Institute of Transportation Engineers or other agencies. In many cases, these parking ratios result in far more spaces than are actually required. This occurs because ratios are typically set as minimums and not maximums. Therefore, builders and developers are free to provide excess parking. The excess parking is provided to prevent complaints from residents, employees, and customers regarding inadequate parking. Commercial landowners, reluctant to risk losing customers due to lack of parking, are particularly sensitive to this issue (Better Site Design). However, oversized parking lots are expensive at many levels. They are expensive to construct and maintain. More parking means more impervious cover, which in turn leads to increased stormwater runoff and decreased groundwater recharge. Increased runoff is expensive to manage, and as seen earlier, has a number of adverse environmental impacts. For more sustainable site design, parking codes should be updated to make calculated parking ratios a maximum possible number of impervious parking spaces that can be built on a project. This measure will not only decrease impervious surface area on the project, but also reduce overall costs. In cases where parking above the maximum is desired, additional spaces should be created either by building parking structures or by using pervious paving materials such as gravel or permeable pavers. Reductions in overall parking lot size can be achieved in a number of ways including reduction of the number of spaces required, reducing the size of individual parking stalls, designated spaces for compact cars, motorcycles and bicycles, and sharing parking between adjacent uses. Although not directly addressed in this section, the opportunities to reduce parking demand through improved pedestrian and public transportation access also should be considered. The use of permeable paving blocks, gravel, or grass can be a viable alternative for low traffic parking areas, emergency access roads, and driveways to increase infiltration and reduce runoff volumes. In addition to reduc- ing parking requirements and imposing maximum parking allotments, ordinances should permit the use of per- 56 Chapter 4 Principles And Practices For Conservation Design meable pavers or other alternative surfaces in appropriate parking situations. (See the Center for Watershed Protection's Stormwater Manager's Fbsource Center, http://www.stormwatercenter.net, for fact sheets on alter- native pavers and porous pavement.) Another recommendation is to require onsite stormwater reduction techniques. Existing landscaped areas in park- ing lots should be used to provide stormwater filtering or infiltration. Bioretention areas are landscaping features adapted to treat stormwater runoff on the development site. They are commonly located in parking lot islands or in peripheral drainage swales. Surface runoff is directed into shallow, landscaped depressions. These depressions are designed to incorporate many of the pollutant removal mecha- nisms that operate in wetland or prairie ecosystems. During storms, runoff infiltrates through the mulch and soil in the system. Runoff from larger storms begins to pond and may be diverted through or past the bioretention area to the storm drain system. The remaining runoff slowly filters through the mulch and prepared soil mix. A portion of the filtered runoff may be collected in a perforated underdrain and conveyed to a detention basin. Bioretention requires seasonal landscaping maintenance. Grassed filter strips(also known as vegetated filter strips, filter strips, and grassed filters)are vegetated areas that are intended to treat sheet flow from adjacent impervious areas. Filter strips function by slowing runoff velocities and filtering out sediment and other pollutants, and providing some infiltration into underlying soils. With proper design and maintenance, filter strips can provide relatively high pollutant removal. Filter strips are best suited to treating runoff from roads and highways, roof downspouts, and small parking lots. Typically, filter strips are used to treat very small drainage areas. For specific design criteria for these practices refer to the list of additional resources at the beginning of this Perception section. The cost to provide on-site stormwater manage- ment may be more expensive than providing off- Model Ordinance Language site management at one regional facility. The Technical Advisory Committee developed the fol- lowing guidelines to assist local governments in mod- Fact ifying parking requirements. Because parking require- The use of bioretention facilities and other on-ite ments extend beyond the scope of residential conser- stormwater management facilities can significant- vation design (the emphasis of this document), often ly reduce the need for storm sewers, thus reduc- into commercial conservation design, the language ing stormwater infrastructure costs. provided below is advisory and will require substan- tial adaptation based on community's needs. Fact Filter strips, bioretention facilities, and dry swales may be placed in dead space areas such as set- backs and traffic islands, minimizing impacts to usable (i.e., buildable) land. (From Better Site Design) 57 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Model Ordinance Language Commentary A. Fbduce parking requirements for low impact uses. The parking section of the zoning or subdivision (usual- ly zoning) ordinance should be reviewed and cases of excessive parking requirements should be corrected. B. The number of parking spaces shall be not lessthan To eliminate overbuilding, the minimum and maximum ( ) and not more than ( ). In cases where parking requirements can be set. In cases where busi- additional spaces are desired, these shall be pro- nesses desire parking beyond the maximum, alterna- vided by building structured parking or using per- tives to conventional parking lots must be used. (See vious materials, where groundwater will not be the Center for Watershed Protection's Stormwater adversely affected by the use of such materials. Manager's Pesource Center, http://www.stormwater- center.net, for fact sheets on alternative pavers and C. New parking lots and structures shall include a per- porous pavement.) centage of designated spaces for compact cars, motorcycles, and bicycles. Compact car spaces shall be smaller than typical spaces. Motorcycle spaces shall be smaller still, and racks or other facilities shall be provided for bicycles. D. In cases where adjacent businesses or other uses Uses that can comfortably share parking often have dif- can reasonably share parking spaces, such as ferent peak periods. For example, a restaurant and a when businesses have staggered needs according medical clinic will draw peak numbers of patrons at dif- to peak times (at the discretion of the Panning ferent times of day. Shared parking reduces situations Director), such sharing is permitted. where overbuilt parking lots sit empty most of the time. E Where groundwater will not be adversely affected While not appropriate for high volume parking areas, by the use of such materials, alternative paving alternative materials are adequate in many situations. materials, such as permeable pavers or gravel, are See the Stormwater Manager's Fbsource Center (cited permitted for overflow parking and other low vol- above)for more information. ume parking areas. F. Businesses served by public transportation may apply for reductions in parking space requirements. G. All off-street parking facilities for ( or more vehicles, not contained in a building or structure, shall be effectively buffered from adjacent uses, especially residential areas. H. Bioinfiltration, filter strips, and other practices shall be included in all off-street parking facilities for U or more vehicles. I. The use of enclosed drainage curb and gutter sys- tems is discouraged in favor of vegetated swales, where feasible. 58 Chapter 4 Principles And Practices For Conservation Design Practice 10: Vegetated Swales Require that vegetated swales be used in street rights-of-way, parking lots, and other paved areas to convey and treat stormwater runoff. Discussion The term"swale" (a.k.a., grassed channel, dry swale, wet Swale, biofilter) refers to a series of vegetated, Perception open channel practices that are designed specifically Snow removal may be more difficult when males to treat and attenuate stormwater runoff for a speci- are used. fied water quality volume. As stormwater runoff flows through the channels, it is treated through filtering by Fact the vegetation in the channel, filtering through a sub- Ibadside swales increase snow storage at the soil matrix, and/or infiltration into the underlying road edge. Smaller snow plows are available. soils. Maintenance of grassed channels mostly involves maintenance of the grass or wetland plant (From Better Site Design) cover. Swales may be used in the street right-0f-way and throughout the site. Most jurisdictions require that curb and gutter systems be installed along residential streets to convey Perception stormwater runoff. Curb and gutter systems, however, Open channel BMPS (like swales) may harbor provide no stormwater treatment and quickly dis- pests and standing water may interfere with charge stormwater directly into streams. By contrast, homeowners' ability to mow their front yards. open vegetated swales that could provide better treat- ment are usually discouraged or prohibited. Unlike Fact curb and gutter systems, which move stormwater with The potential for snakes and other vermin can be virtually no treatment, open vegetated swales remove minimized by more frequent mowing. pollutants by allowing infiltration and filtering to occur. Open swales also encourage groundwater Fact recharge, and can reduce the volume of stormwater Grass channels are not designed to detain water runoff generated from a site. (Better Site Design, for any length of time. Properly designed dry CW P) males will drain within 24 hours. Compared to roadside ditches, vegetated males have (From Better Site Design) a wider bottom, gentler slopes, and denser vegetation. They are designed to detain stormwater flows for ten to twenty minutes to allow sediment and heavy particles to filter out. Vegetated males are relatively easy to construct and maintain. If applied under the right conditions, and installed properly, grass channels experience few of the nui- sance problems associated with roadside ditches. It should be noted that the feasibility of using males at a development site is determined by a number of factors, including drainage area, slope, length, housing density, and street type. In general, open channel systems are most appropriate for smaller drainage areas, mildly sloping topography, and housing density less than four dwelling units per ace. For specific design criteria for these practices refer to the list of additional resources at the beginning of this section. 59 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Model Ordinance Language Commentary Improved sites. All sites shall be dedicated in a condition ready for full Existing language with suggested additional language service of electrical, water, sewer, and streets(includ- in bold. ing vegetated swales or enclosed drainage and curb and gutter)as applicable to the location of the site, or Other references to curb/gutter construction may be acceptable provision made therefore. The use of found in the subdivision ordinance, the planned devel- swales vegetated with native materials is encouraged opment ordinance, and in ordinances pertaining to as a method of stormwater conveyance to decrease new road design and parking lot design. These refer- runoff velocity, allow for biofiltration, allow suspend- ences can be updated similarly to the improved site ed sediment particles to settle, and remove pollutants. reference given here. 60 Chapter 4 Principles And Practices For Conservation Design Practice 11 : Walkways Establish flexible design standards for walkways. The typical form of pedestrian circulation in residential subdivisions is the sidewalk. A sidewalk system adds a social as well as a transportation element to a community. It is a unified linear element that provides a common space within a neighborhood. However, sidewalks may not always be appropriate. They increase the amount of impervious surface on a site, which increases stormwater runoff. For conservation design, the preferred approach is to mandate`walkways' within developments. These walkways can take various forms, from traditional sidewalks to rustic trails, depending on the nature of the development. In densely developed or urban areas, sidewalks are generally the most appropriate form of walkway. In perception certain cases, where sidewalks are necessary, the The Americans with Disabilities Act (ADA) total impervious surface area can be reduced by con- requires sidewalks on both sides of the street. structing sidewalks on only one side of the street. Fact In cases of less dense development, sidewalks can be The ADA requires at least one accessible route replaced with a trail system through the development, from public streets, parking areas, and passen- connecting homes to open space. Materials also may ger loading zones along a route that generally be varied; for an informal walkway system, materials coincides with that of the general public. There such as gravel, mulch, wood chips, or grass clippings are no specific restriction on roadway sidewalks. can effectively replace asphalt or concrete. Further, a trail system can be designed to take advantage of (From Better Site Design) contiguous open space on other development sites, connecting through multiple sites for a community- wide trail network, where ownership arrangements and easements permit (Countryside Program, 3C). Perception Residents want sidewalks on both sides of the Any conservation development must find a balance street. between providing a sufficient walkway system to support pedestrian uses, and minimizing impervious surfaces. Fact There is no appreciable market difference The key to successfully updating local ordinances is to between houses that are directly served by side- provide for flexibility in walkway design. The exact walks (i.e., the sidewalk is on the same side of nature of the walkway system depends ultimately on the street)and houses that are not directly served community preferences and the nature of the devel- (i.e., the sidewalk is on the opposite side of the opment site. street). Some residents do prefer to have access to a sidewalk in front of their property, while oth- Model Ordinance Language ers prefer no sidewalks. The types of preferences The following model ordinance language can be adapt- are logically resolved at the time buyers purchase ed to modify existing local codes and ordinances. the property. Blanks and bracketed ([ ]) sections should be filled in with language appropriate for each community. (From Better Site Design) 61 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Model Ordinance Language Commentary A.Walkways shall be provided to connect residential When is a development "urban" in character? This areas to common open space areas and to provide decision must be made within the context of each com- convenient pedestrian access throughout the con- munity—as a general rule of thumb, densities requir- servation development and from the conservation ing curb and gutter construction are probably "urban" development to other areas of the community. and will likely benefit from sidewalks on both sides of the street. B. When the proposed walkway system provides pedestrian access equal to or better than the provi- sion of sidewalks along street rights-0f-way, side- walks along public streets are not required. C. Unless a development is `urban' in character, side- Walkways, more similar to trail systems than conven- walks or walkways are not required on both sides tional sidewalks, will not require the same snow street rights-0f-way, as long as sufficient access to removal practices as conventional sidewalks. The per- homes and businesses is provided. vious materials suggested can be shoveled or simply packed down through use. D. Walkways, or a portion of the walkways, should be E Walkways should be maintained similarly to the constructed of pervious materials such as gravel, common open space within the development. See wood chips or other similar material. R-actice #7, Natural Area Management, for more information. 62 Chapter 4 Principles And Practices For Conservation Design Practice 12: Driveway Design Update ordinances to eliminate length and width requirements for driveways, and to permit alternative driveway surfaces and shared driveways that connect two or more homes together. Like roadways in general, driveway lengths are naturally shortened by the form of conservation design. Homes are located closer together and closer to roads and streets. As a result, long driveways are rarely necessary to provide adequate access to homes and garages. Thoughtful techniques can be employed to further reduce drive- way surface areas. In many cases, common residential drives serving 2-5 housing units are appropriate. Because driveways can be constructed to reduced standards with regard to design speed, alignment, compaction, and pavement or gravel surfaces, this is a low impact way to save on impervious surface area. Ordinances should be updated to remove length and width requirements for driveways, since these can be built to minimum standards. since conservation design encourages the use of on-street parking, it is less important to provide overflow parking in private driveways. While permeable paving blocks are only sometimes appropriate for parking areas and public roadways, they are nearly always appropriate for driveways. Allow the use of permeable pavers, gravel, or other pervious surfaces for driveways in conservation subdivisions. (See the Center for Watershed R-otection's Stormwater Manager's Fbsource Center, http://www.stormwatercenter.net, for fact sheets on alternative pavers and porous pavement.) Model Ordinance Language The following model ordinance language can be adapted to modify existing local codes and ordinances. The language given here in advisory in nature and will require substantial adaptation to be effective in local ordinances. Perception Alternative driveway surfaces make snow removal more difficult. Challenge Paver blocks can be damaged by snowplows and stone, gravel, or cobble driveways are diffi- cult to plow. Brick, porous asphalt, and pervious concrete will perform similarly to conventional pavement although sand cannot be used on porous pavement. (From Better Site Design) 63 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Model Ordinance Language Commentary A. Private Drives: Private drives shall be in compliance Detailed standards are not necessary for driveway with the following requirements: construction. 1. Private drives shall be built to the minimum length and width necessary to serve the resi- dence. 2. Private drives, where feasible, shall be built with Alternative surfaces can reduce overall imperviousness. alternative surfaces such as gravel or permeable pavers, and also can use alternative construction forms such as the two-track form. These materials should be used only when groundwater will not be adversely affected by their use. B. Common Drives: Common drives shall be permitted Common drives are a type of private street. The dis- in compliance with the following requirements: tinction is that common drives must comply with the standards for residential driveways, which is a lesser 1. A common drive can serve multiple units. standard than that required for private streets. The municipality or county is not responsible for the main- 2. Common drives shall be built to the minimum tenance of common drives. length and width necessary to serve the resi- dences. 3. Common drives, where feasible, should be built with alternative surfaces such as gravel or per- meable pavers, and can also use alternative construction forms such as the two-track form. These materials should be used only when groundwater will not be adversely affected by their use. 4. A common drive shall extend from a public or This requirement is necessary because common drives private street and shall not connect to any other are built to lower standards than other types of private existing or planned public or private street. street. This assures that common drives are not mis- used in the development process. 64 Chapter 4 Principles And Practices For Conservation Design Practice 13: Fbof Rinoff Management Perception Discourage discharge of rooftop runoff into storm sewers. Fbdirected rooftop runoff may increase a property Fbquire or encourage alternative roof runoff manage- owner's maintenance burden. ment techniques. Encourage green roof designs. Fact In most conventional developments, stormwater from When designed properly, on-lot bioretention rooftops is piped into a storm drain that directly leads into areas provide an attractive landscaping feature an engineered stormwater management facility. Fbofsare that does not require supplemental water. one of the most important sources of concentrated runoff (From Better Site Design) from developed sites. One of the best ways to decrease the need for stormwater management systems is to man- age rooftop runoff on site, instead of moving stormwater through a conveyance system. Fbdirecting rooftop runoff is a sig- nificant measure for reducing downstream impacts and can decrease annual runoff volumes by as much as 50%for medi- um and low density land uses. It also can significantly reduce the annual pollutant load. In addition to achieving specific stormwater runoff management objectives, rooftop runoff management also is aesthetically and socially beneficial. Although there are a wide variety of rooftop runoff treatment options, they all can be classified into one of three categories: 1)practices that infiltrate rooftop runoff; 2)practices that divert runoff or soil moisture to a pervious area; and 3)practices that store runoff for later use. The best option depends on the goals of a community, the feasibility at a specific site, and the preferences of the homeowner. The practice most often used to infiltrate rooftop runoff is the dry well. In this design, the storm drain is directed to under- ground rock-filled trenches. French drains or Dutch drains also can be used for this purpose. In these designs, the relatively deep dry well is replaced with a long trench with a perforated pipe within the gravel bed to distribute flow throughout the length of the trench. Rinoff can be diverted to a pervious area or to a treatment area using site grading, channels, and berms. Treatment options can include grassed swales, bioretention, or filter strips. Alternatively, rooftop runoff can simply be diverted to per- vious lawn areas, as opposed to flowing directly to the street, and thus the storm drain system. R-actices that store rooftop runoff, such as cisterns and rain barrels, are the simplest in design of all rooftop runoff treat- ment systems. Some of these practices are available commercially and can be applied in a wide variety of site conditions (Center for Watershed F rotection, www.cwp.org). Perception One important design consideration for rooftop runoff practices is Wet basements will result from re-direct- to locate infiltration areas suff idently far from house founclationsto ing rooftop runoff. prevent undermining the foundation or seepage into basements. These practices should be separated at least ten feet from the house Fact to prevent these problems. These conditions can be minimized by setting specific criteria regarding the dis- Vegetated roof covers, also called green roofs and extensive roof tance that downspouts must discharge gardens, involve blanketing roofs with a veneer of living vegeta- from foundations, minimum adjacent lion. These systems can reduce roof runoff as well as provide an slopes away from houses, and adequate aesthetic benefit to homeowners and communities. construction inspection. For specific design criteria for these practices refer to the list of (From Better Site Design) additional resources at the beginning of this section. 65 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Model Ordinance Language Commentary A. Direct rooftop runoff and sump pumps to pervious areas such as yards, open channels, or vegetated areas, and avoid routing rooftop runoff and sump pumps to the roadway and the stormwater con- veyance system. B. Fboftop drainage should be illustrated on the engi- neering plan necessary for building permit issuance C. Green roofs may be used to reduce stormwater A green roof is the modern equivalent of the roof gar- runoff. den or sod roof. While these older technologies were heavy and cumbersome, today's green roofs are light- weight and include sufficient drainage and roof pro- tection. Green roofs are new technology; as new tech- niques emerge accepted practice for green roof use may change. It is the responsibility of the applicant to review the state of the art for green roof technology when submitting applications for their use. 66 Chapter 4 Principles And Practices For Conservation Design Principle D. Implement Sustainable Stormwater Management Techniques Sustainable stormwater management techniques can decrease flooding, improve water quality, decrease erosion and sedimentation, and improve groundwater recharge. Discussion Sustainable stormwater management is perhaps the most important benefit of conservation design. Nearly every conservation design practice contributes to improved stormwater management in some way. The stormwater ben- efits outlined in Principles A-C are summarized here. In addition, this section also includes model ordinance lan- guage for the implementation of an Urban Fbnoff Mitigation Ran, a general strategy for improving stormwater management. Stormwater runoff has been traditionally treated as a by-product of development to be disposed of as quickly and efficiently as possible. The result often has been increased flooding, degradation of water quality, soil erosion and sedimentation, and reduced groundwater recharge. Stormwater Ordinances Most of the counties in the region have adopted or are close to adopting countywide stormwater ordinances. It is not the intent of this ordinance to replace those ordinances but rather to integrate the goals of countywide and municipal ordinances with the goals of conservation design. The countywide stormwater management ordinances may be found on the following web sites: DuPage County: http://www.dupageco.org/dec/ SW Ord2000.pdf Lake County: http://www.co.lake.i1.ust smc/wdo/wdodoc.pdf Will County: http://www.willcountylanduse.com/engineering/ index.html McHenry County: http://www.co.mchenry.il.us/CountyDpt/ plandev/WaterShedOrd2002.pdf Kane County: http://www.co.kane.il.us/ kcstorm/ Draft/ revadoptord.pdf Cook County: Contact your municipality. Best Management Practices It is the intent of conservation design to encourage the use of Best Management Practices (BMPs) which are defined as structural, vegetative, or managerial approaches designed to reduce stormwater runoff volume, maxi- mize natural groundwater recharge, and treat, prevent, or reduce degradation of water quality due to stormwa- ter runoff. All development projects subject to review under the requirements of this ordinance should be designed, constructed, and maintained using BMPs. The particular facilities and measures required on�ite shall reflect and incorporate existing grade, natural drainage and storage features, and wetlands on the site to the maximum extent feasible. It is assumed that a municipality will have a stormwater ordinance in place or will make reference to a county ordinance as well as guidance manual for BMPdesign and implementation. The design manual should contain information on sizing criteria, performance criteria, and guidance on selection and location of BMPS. Currently there is not a technical reference manual for the practices in this ordinance but there are several references given in each section of Chapter 4. Both Kane and Lake Counties have Technical Reference Manuals available on-line for their stormwater ordinances and the State of Maryland has one available that includes many of the practices listed in this ordinance (see additional resources). 67 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Stormwater Treatment Train The open space and permeable landscapes within a conservation development should be creatively used to infil- trate, filter, and store runoff. Open space areas can be situated along natural drainage patterns and a series of diverse landscapes convey water through a natural treatment process. The channeling of runoff through a series of natural landscapes can result in the retention of stormwater on site, settling and pollutant removal, and lower runoff volume and velocity. Stormwater management plans can incorporate design solutions that direct runoff to grass swales that feed into a prairie or woodlands. In some cases, the sequence could be extended to a con- structed wetland (The Countryside Program). Benefits, Examples, and I�bsources Implementing sustainable stormwater management techniques can be beneficial to the local community, the devel- oper of the site, and homeowners, the eventual end-users of the new development. See Chapter 2 for a full dis- cussion of the economic benefits of this principle. Developments with improved stormwater management facilities are more marketable because they provide aes- thetic features such as rain gardens, wet detention basins, and natural drainage areas that attract wildlife. Additional Resources Center for Watershed Protection. 1998. Better Site Design: A Handbook for Changing Development Rules in Your Community. Ellicott City, Maryland. Center for Watershed Protection. 1996. Design of Stormwater Filtering Systems, Prepared for: Chesapeake Pesearch Consortium Solomons, MD and US EPA F;bgion V Chicago, IL Kane County Department of Environmental Management. 2001. Kane County Stormwater Technical Guidance Manual. http://www.co.kane.il.us/ kcstorm/ Draft/Technical RNALpdf, January 15, 2003. Lake County Stormwater Management Commission. 1992. Technical Reference Manual. http://www.co.lake. il.us/smc/tac/trm.htm, January 15, 2003. Maryland Department of the Environment. 2000. 2000 Maryland Stormwater Design Manual Volumes I & ll. Baltimore. http://www.mde.state.md.us/ Programs/WaterP-ograms/SedimentandStormwater/stormwater design/ index.asp, .anuary 15, 2003. Northeastern Illinois Panning Commission. 1997a. Reducing the Impacts of Urban Rinoff: The Advantages of Alternative Site Design Approaches. Chicago. Prince George's County Department of Environmental Resources. 1997. Low Impact Development. Laurel, MD. 68 Chapter 4 Principles And Practices For Conservation Design Urban %noff Mitigation Plan An overarching theme in the design of conservation developments is the management of water resources. If applied, most of the practices discussed in this resource manual affect the rate, volume, and quality of the water managed on-site and directed off-site. In recognition of this fact and in order to fully integrate water management into site design, it is suggested that communities revise their subdivision ordinances by including the requirement for an Urban Runoff Mitigation Ran. Rather than dictate exactly what standards are necessary in a conservation development, this is a performance criterion that provides a flexible mechanism to encourage the use of practical techniques when considering site-specific conditions. The purpose of an Urban Runoff Mitigation Ran is to permanently modify the structural causes of urban runoff pol- lution. This includes the reduction of both runoff volume and runoff contamination from existing residential and nonresidential properties and from future developments. This is accomplished by ensuring that project sites maxi- mize on-ite infiltration of runoff and ensuring that stormwater is directed or contained so as not to become pol- luted by passage through contaminating material. A community may not use all of the practices listed in this ordinance but many will be needed to reach the goal. For example, while there is not necessarily a mandated percent open space in conservation developments because of the potential inflexibility given some smaller or infill sites, it is assumed that in order to meet the runoff mitigation goals listed below a large percentage of land will be left undeveloped or developed in a manner that reduces the amount of stormwater runoff. Model Ordinance Language The following model ordinance language can be adapted to modify existing local codes and ordinances to include the requirement for an Urban Runoff Mitigation Ran to be submitted and approved in connection with any new development. Blanks and bracketed ([ ])sections should be filled in with language appropriate for each com- munity. 69 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Model Ordinance Language Commentary Urban runoff reduction requirements for new subdivisions The following urban runoff reduction requirements Many stormwater ordinances include language similar shall apply to all persons submitting applications for to this, while subdivision ordinances include contra- new development within the [Municipality or County]. dictory requirements such as curb and gutter construc- tion, elevated landscape islands, the use of roads as A.At the time of submittal of an application for a new primary drainage elements, and other similar tech- development project, an applicant shall be niques. The practices that follow offer specific guid- required to submit an Urban Rinoff Mitigation Plan ance and language for updating sections of the sub- to the [Department of Engineering]. division ordinance to eliminate these contradictions. B. In developing an Urban Runoff Mitigation Flan, an applicant shall design for infiltration and treatment of projected runoff for the new development such that there is no increase in runoff volume for all events up to the 2-rear storm event. The design ele- ments utilized by an applicant shall include an appropriate combination of those provided on the list below so long as the required projected runoff infiltration or treatment is achieved: 1. Utilize permeable areas to allow more infiltration of runoff into the ground through such means as: a. Biofilteration; b. Filter strips; See Vegetated Swales, Fbadway Design, Parking Lot c. Swales; Design, Driveway Design, and Fbof %noff d. Infiltration trenches; Management. e. Green roofs; and f. Permeable pavement. 2. Direct runoff to permeable areas and/or utilize stormwater storage for reuse or infiltration by such means as: a. Orienting roof runoff towards permeable sur- faces, drywells, French drains, or other Best See Fbof Rinoff Management Management Practices (BMPS) rather than directly to driveways or non-permeable sur- faces so that runoff will penetrate into the ground instead of flowing off-ite. b. Grading impervious surfaces to direct runoff See Roadway Design and Parking Lot Design to permeable areas, utilizing level spreaders or other methods to distribute the impervious runoff over pervious surfaces. 70 Chapter 4 Principles And Practices For Conservation Design Model Ordinance Language (continued) Commentary c. Using cisterns, retention structures, or rooftops See Fbof Runoff Management to store precipitation or runoff for reuse. d. Fbmoving or designing curbs, berms or the See Vegetated Swales, Fbadway Design like so as to avoid isolation of permeable or landscaped areas. 3.The applicant also must meet release rate stan- dards of the [stormwater ordinances]. The deten- tion calculations may reflect the influence of BMPS used to achieve the runoff volume standard of this ordinance. 4.The Urban Runoff Mitigation Plan also must include the applicant's plan for the maintenance of all BMPs requiring ongoing maintenance. 5.All Urban Fbnoff Mitigation Plans must include the applicant's signed statement accepting responsibility for all structural and treatment con- trol BMP maintenance. The transfer of property subject to an Urban %noff Mitigation Ran must include as a written condition to the transfer that the transferee assumes full responsibility for maintenance of any structural, and/or source or treatment control BM Fs. C.AII computations within the Urban %noff Mitigation Ran shall calculate runoff from hydraulically con- nected impervious and pervious surfaces separate- ly. Composite %noff Curve N umbers shall not be used to calculate runoff from areas containing both pervious and hydraulically connected impervious surfaces. Impervious surfaces may be considered hydraulically disconnected when the impervious runoff is distributed over an area at least as large as the impervious surface. In these cases, a com- posite curve number may be used. Fbnoff captured within infiltration trenches, dry wells, or similar infiltration based BMFs may be sub- tracted from site runoff volume calculations up to the storage volume of the infiltration practice. 71 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Model Ordinance Language (continued) Commentary Vegetated green roof systems with a minimum 3-inch growing medium may be assumed to have similar runoff characteristics as hydrologic soil group"C soils. D.The [Municipality or County Director of Engineering} shall review the proposed Urban Rdjnoff Mitigation Ran for compliance with the stan- dards set forth in subsection (B) of this Section. E The Director of the [Department of Engineering] or his or her designee shall approve or disapprove the plan. If the plan is disapproved, the reasons for dis- approval shall be given in writing to the developer. Any plan disapproved by the Director of the [Department of Engineering] or his or her designee must be revised by the developer and resubmitted for approval. F. A waiver from subsection (b) of this Section may be issued by the Director of the [Department of Engineering] or his or her designee if the petitioner shows impracticability of implementing these require- ments. Recognized circumstances demonstrating impracticability include: (i) extreme limitations of space for treatment; (ii) unfavorable (i.e. hydrologic soil group "D" soils) or unstable soil conditions at a site to attempt infiltration; and (iii) risk of groundwa- ter contamination because a known unconfined aquifer lies beneath the land surface or an existing or potential underground source of drinking water is less than ten feet from the soil surface. G.If a waiver is granted for impracticability, the peti- tioner will be required to transfer the savings in cost, as determined by the Director of the [Department of Engineering], to a [Municipality or County] stormwa- ter mitigation fund to be used to promote regional or alternative solutions for urban runoff pollution in the storm watershed, which may be operated by a pub- lic agency or a non-profit entity. H.No building permit or other planning approval shall be issued until an Urban R inoff Mitigation Ran has been approved by the[Department of Engineering]. 72 Bibliography and Technical Assistance Bibliography —. February 2000. Putting the Freeze on Heat Islands. American City and County. American Association of State Highway and Transportation Officers. 2001. A Policy on Geometric Design of Highways and Streets. Arendt, Randall G. 1996. Conservation Design for Subdivisions: A Practical Guide to Creating Open Space Networks. Washington D.C.: Island Press. Arendt, Randall G. 1999. Growing Greener: Putting Conservation into Local Plans and Ordinances. Washington D.C.: Island Press. The Biodiversity Project. No Date. Getting on Message/About Sprawl: Economic Costs at a Glance Fact Sheet. Brabec, Elizabeth. 1992. On the Value of Open Spaces. Scenic America Technical Information Series, vol. 1 , no. 2. Center for Watershed Protection. 1998. Better Site Design: A Handbook for Changing Development Fbles in Your Community. Ellicott City, Maryland. Center for Watershed Protection. 1996. Design of Stormwater Filtering Systems, Prepared for: Chesapeake Research Consortium Solomons, MD and US ERA Fagion V Chicago, IL Center for Watershed Protection. 1995. Site Planning for Urban Stream Protection. Center for Watershed Protection, Stormwater Manager's Fasource Center. 2002. Better Site Design Fact Sheet: Alternative Pavers. http://www.stormwatercenter.net, December 19, 2002. Center for Watershed Protection, Stormwater Manager's Resource Center. 2002. Stormwater Management Fact Sheet: Porous Pavement. http://www.stormwatercenter.net, December 19, 2002. Center for Watershed Protection, Stormwater Manager's Fasource Center. 2002. Open Space Model Ordinance. http://www.stormwatercenter.net/ Model%20Ordinances/ open space model ordinance.htm, December 20, 2002. Chicago Wilderness. 1999a. Biodiversity Ibcovery Pan. Chicago. Chicago Wilderness. 1999b. An Atlas of Biodiversity. Chicago. City of Kensosha, Wisconsin. Zoning Ordinance for the City of Kensoha, Wisconsin, Section 6.0 Parking and Loading Requirements. Kenosha. City of Napa, California. Ordinance on Rparian Habitat Areas. http://wwwstorrmwatercenter.net/ Model%20Ordinances/ napa-buffer, January 15, 2003. The Conservation Foundation website. http://www.theconservationfoundation.org, January 15, 2003. 73 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Conservation Research Institute. 2001. TCSP—Fdoute 47/ Kishwaukee Rfver Transportation Corridor Project Preliminary Master Ran—Long Version. The Countryside Program. 1996. Balancing Conservation & Development in Northeast Ohio. The Countryside Program. 1998. Conservation Development Resource Manual. Ohio: Western Feserve Resource Conservation and Development Council. Crompton, John L 2001. Parks and Economic Development, Ranning Advisory Service Report Number 502. Chicago: Ranners Press. Diehl, J. and T. Barrett. 1988. The Conservation Easement Handbook. Washington DC: Washington D.C: Land Trust Alliance. Greenroofs.com. http://www.greenroofs.com/ , February 17, 2003. Gibbons, Jim. Technical Paper#5, Parking Lots. Connecticut: UConn Cooperative Extension Land Use. Illinois Department of Transportation. 1999. Raral Two-Lane/ Multilane State Highways. Johnson County, Iowa. Conservation Subdivision Design Ordinance. http://www.iohnson- county.com/zoning/sensitiveareas/csd.htm, December 20, 2002. Kane County, IL 2002. Kane County Code. http://www.co.kane.il.us, January 15, 2003. Kane County Department of Environmental Management. 2001. Kane County Stormwater Technical Guidance Manual. http://www.co.kane.il.us/ kcstorm/ DrafU Technical F1NALpdf, January 15, 2003. Kendall County, IL 2002. Kendall County Zoning Ordinance, Section 8.00 Fbsidential District. Kulash, Walter M. 2001. Residential Streets, 3`° Edition. Urban Land Institute, National Association of Home Builders, American Society of Civil Engineers, Institute of Transportation Engineers. Lake County Stormwater Management Commission. 2001. Watershed Development Ordinance. Lake County Stormwater Management Commission. 1992. Technical Reference Manual. http://www.co.lake.i1.us/smc/tac/trm.htm, January 15, 2003. Lerner, Steve, and William Fbole. 1999. Economic Benefits of Farks and Open Space. San Francisco: The Trust for Public Land. Maryland Department of the Environment. 2000. 2000 Maryland Stormwater Design Manual Volumes I & II. Baltimore. http://www.mde.state.md.us/Programs/WaterR-ograms(Sed i mentandStormwater/stormwater design/index.asp, January 15, 2003. Mengler, Jaffrey. 1997. Native Rant Guide for Streams and Stormwater Facilities in Northeastern Illinois. Chicago: USDA Natural Fbsources Conservation Service. 74 Bibliography and Technical Assistance Metropolitan Area Panning Council (Boston). 2000. Open Space Residential Development or Conservation Subdivision Design (CSD) Model Bylaw. Boston. Minnesota Panning Environmental Quality Board. 2000. From Policy to Fbality: Model Ordinances for Sustainable Development. Minnesota. Murphy, H. Lee. September 23, 2002. Wetlands No Longer Soak Rans for Many Builders. Crain's Chicago Business. National Park Service. 1995. Economic Impacts of Protecting Rivers, Trails and Greenway Corridors. Washington D.C. Northeastern Illinois Panning Commission. 2000. Protecting Nature in Your Community: A Guidebook for Reserving and Enhancing Biodiversity. Chicago. Northeastern Illinois Panning Commission. 1997a. Fbducing the Impacts of Urban Fbnoff: The Advantages of Alternative Site Design Approaches. Chicago. Northeastern Illinois Ranning Commission. 1997b. Natural Landscaping for Public Officials: A Source Book. Chicago. Northeastern Illinois Ranning Commission. 1997c. Northeastern Illinois Regional Greenways and Trails Ran. Chicago. Northeastern Illinois Panning Commission. 1996. Model Roodplain Ordinance for Communities Within Northeastern Illinois. Chicago. Northeastern Illinois Panning Commission. 1994. Environmental Considerations in Comprehensive Panning: A Manual for Local Officials. Chicago. Northeastern Illinois Panning Commission. 1991. Model Soil Erosion and Sediment Control Ordinance: A Guide for Local Officials. Chicago. Northeastern Illinois Panning Commission. 1990. Model Stormwater Drainage and Detention Ordinance: A Guide for Local Officials. Chicago. Northeastern Illinois Panning Commission. 1988. Model Stream and Wetland Protection Ordinance for the Creation of a Lowland Conservancy Overlay District: A Guide for Local Officials. Chicago. Oregon Transportation and Growth Management Program. 2000. Model Development Code and User's Guide for Small Cities. Oregon. Packard, S., and C. Mutel, editors, 1997. The Tallgrass Fbstoration Handbook. Washington D.C.: Society for Ecological Fbstoration. Pennsylvania Department of Conservation and Natural Fbsources. 1997. Growing Greener: A Conservation Panning Workbook for Municipal Officials in Pennsylvania. Pennsylvania. Pennsylvania State University. Center for Green Fbof Fbsearch web site. http:// hortweb.cas.psu.edu/ research/greenroofcenter/about ctr.html, February 17, 2003. 75 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Rzzo & Associates, Ltd. 2001. Cost Comparison New Turf Grass Lawn from Seed Vs. Native Landscape from Seed. Leland, Illinois. Prince George's County Department of Environmental Fesources. 1997. Low Impact Development. Laurel, MD. Rappaport, Brett. 1993. As natural landscaping takes root we must weed out the bad laws—how natural land- scaping and leopolds's land ethic collide with unenlightened weed laws and what must be done about it. The John Marshall Law Feview, vol. 26, no. 4. Rivers, Trails and Conservation Assistance. 1995. Economic Impacts of Protecting Rivers, Trails, and Greenway Corridors. Washington, D.C.: National Park Service. Scheer, Fbddy. April 11, 2002. Urban Forests Make Environmental and Economic Sense. Ethe Environmental Magazine. Shoup, Donald C. 1995. An Opportunity to (educe Minimum Parking Requirements. Journal of the American Ranning Association, vol. 61, no. 1. Susnjara, Bob. October 1, 2002. Why Your Water Rates Might be Increasing. Daily Herald. Swift, Peter. 1998. Residential Street Typology and Injury Accident Frequency. Swift and Associates. http:// members.aol.com/ Phswi/Swift-street.html, December 11, 2002. USDA-Natural Fesource Conservation Service Chicago Metro Urban and Community Assistance Office, US Environmental Protection Agency, Region 5, US Fish and Wildlife Service, Chicago Feld Office, US Army Corps of Engineers, Chicago District. 1997. Native Rant Guide for Streams and Facilities in Northeastern Illinois. Naperville USDA-Natural Resource Conservation Service, Illinois Environmental Protection Agency. 2002. Illinois Urban Manual: A Technical Manual Designed for Urban Ecosystem Protection and Enhancement. Champaign. United States Environmental Protection Agency. 2002a. Model Ordinances Language for Open Space Development. http://www.epa.gov/owow/ nps/ordinance/ mol3.htm, December 20, 2002. United States Environmental Protection Agency. 2002b. Weedlaws. http://www.epa.gov/grtlakes/greenacres/weedlaws, January 15, 2003. United States Environmental Protection Agency. 2002c. Landscaping with Native Rants, Wild Ones Handbook, and Landscaping with Native Rants, and Great Lakes Rants. http://www.epa.gov/grtlakes, January 15, 2003. University of Wisconsin Extension. 2000. An Ordinance for a Conservation Subdivision. Wisconsin. Wenger, Seth and Laurie Fowler. Conservation Subdivision Ordinances. Atlanta Regional Commission. Will County. 2002. Will County Stormwater Management Ordinance. Wilson, Rchard W. 1995. Suburban Parking Fbquirements: A Tacit Policy for Automobile Use and Sprawl. Journal of the American Panning Association, vol. 61, no. 1. 76 Bibliography and Technical Assistance Technical Assistance Northeastern Illinois Planning Commission County Stormwater Agencies 222 South Rverside Raza, Suite 1800 Chicago, IL60606 Lake County Stormwater Management Commission (312)454-0400 333-B Peterson Fbad http://www.nipc.cog.i1.us Libertyville, IL60048 (847) 918-5260 Chicago Wilderness http://www.co.lake.i1.us/smc/ 8 South Michigan Avenue, Suite 900 Chicago, IL60603 McHenry County Planning and Development (312) 346-2540 ext. 30 Department http://www.chicagowilderness.org 2200 N. Seminary Avenue Woodstock, II 60098 The Center for Watershed Protection (815)334-4560 8390 Main Street, Second Roor http://www.co.mchenry.il.ust CountVDpt/ plandev/d Blicott City, MD 21043 efault.asp Phone: (410)461-8323 Fax: (410)461-8324 Kane County Department of Environmental hftp://www.cwp.org Management 719 Batavia Avenue The Conservation Foundation Geneva, IL60134 10 South 404 Knoch Knolls Fbad (630) 208-5118 Naperville, Illinois 60565 http://www.co.kane.i1.us/ Environment/ ind ex.htm (630)428-4500 http://www.theconservationfoundation.org Will County Land Use Department 58 East Clinton St. Campaign for Sensible Growth Suite 500 25 East Washington, Suite 1600 bliet, Illinois 60432 Chicago, IL60602 (815) 727-8631 F hone: (312) 863.6009 http://www.wilicountylanduse.com/engineering/ Fax: (312) 922-5619 http://www. growingsensibly.org DuPage County Department of Environmental Concerns 421 N County Farm Fbad Wheaton Illinois 60187 (630) 682-7220 http://www.dupageco.org/dec/default.html Cook County Department of Planning and Development 69 West Washington Suite 2900 Chicago, IL 60602 (312) 603-1000 77 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual 78 Appendix A Definitions Appendix A: Definitions Definitions These definitions are intended to be incorporated into existing ordinances. Many of these terms may already be defined in the ordinances, in which case care must be taken to ensure that conflicting definitions are eliminated and terms are used consistently throughout each ordinance, and throughout the collection of ordinances that define each community's development process. For the purpose of these regulations the following terms, whenever used in these regulations, shall have the mean- ing herein indicated: Active Recreation: Leisure time activities characterized by repeated and concentrated use of land, often requiring equipment and taking place at prescribed places, sites, or fields. Examples of active recreation facilities include golf courses, tennis courts, swimming pools, softball, baseball, and soccer fields. For the purpose of these regu- lations, active recreation facilities do not include paths for bike riding, hiking, and walking and picnic areas. Association: A legal entity operating under recorded land agreements or contracts through which each unit owner in a conservation development is a member and each dwelling unit is subject to charges for a proportionate share of the expenses of the organization's activities such as maintaining restricted open space and other common areas and providing services needed for the development. An association can take the form of a homeowners' associ- ation, community association, condominium association or other similar entity. Best Management Practices("BMP'): Practices principally applicable to construction sites, parking lots, and new developments that reduce the toxicity contained in, and the volume of, water that runs into storm drains, treatment facilities, and waterways. Bioretention: Ibtention of stormwater through the use of vegetated depressions engineered to collect, store, and infiltrate runoff. Building Envelope: An area within a conservation development that is designated as a location within which a dwelling unit is to be placed in compliance with the building setback and spacing requirements established by the zoning regulations. A building envelope may or may not be located within a sublot and may or may not have frontage on a public street. Buffer: A buffer preserves, provides access to, or otherwise serves as necessary adjunct to natural areas by pro- tecting streams, lakes, wetlands, soil, air, and habitat. Buffers include, but are not limited to, areas of predomi- nantly deeply rooted native vegetated land adjacent to channels, wetlands, or lakes for the purpose of stabilizing banks, reducing contaminants including sediments in storm water that flows to such areas. Land Use Buffer: Land area used to separate or visibly shield and/or screen one use from another. Rparian Buffer: A naturally vegetated area located adjacent to streams and rivers that is intended to stabilize banks and limit erosion. Wetlands Buffer: An area of undisturbed natural vegetation located adjacent to the perimeter of the wetlands. 79 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Common Area: Any land area, and associated facilities, within a conservation development that is held in common ownership by the residents of the development through a Homeowners' Association, Community Association or other legal entity, or which is held by the individual members of a Condominium Association as tenantsmin-common. Common Drive: A private way which provides vehicular access to at least two but not more than dwelling units. Conservation Development: A contiguous area of land to be planned and developed as a single entity, in which buildings are accommodated under more flexible standards, such as building arrangements and setbacks, than those that would normally apply under conventional regulations, allowing for the flexible grouping of structures in order to conserve open space and existing natural resources. Conservation Easement: A legal interest in land which restricts development and other uses of the property in per- petuity for the public purpose of preserving the rural, open, natural or agricultural qualities of the property. Dwelling, Detached Single-Family: A building designed for, or used exclusively for, residence purposes by one family situated on a parcel having a front, side, and rear yard. Dwelling, Single-Family Attached: Dwelling units that are structurally attached to one another, side by side, and erected as a single building, each dwelling unit being separated from the adjoining unit or units by a party wall without openings extending from the basement floor to the roof with each unit including separate ground floor entrances, services, and attached garages. Fen: A wetland that receives some drainage from surrounding mineral soil and usually supports marshlike vegetation. Roodplain: That land adjacent to a body of water with ground surface elevations at or below the 100-year frequency flood elevation. Roodway: That portion of the floodplain (sometimes referred to as the base floodplain or Special Rood Hazard Area) required to store and convey the base flood. The floodway is the 100-year floodway as designated and regulated by the Illinois Department of Transportation / Division of Water Resources. The remainder of the flood- plain which is outside the regulatory floodway is referred to as the flood fringe or floodway fringe. Gross Density: Density calculated by dividing the project area by the lot size, with no adjustment made for roads, off-sized lots, etc. For example, if the standard zoning requires a minimum lot size of one-quarter acre, the GROSS density—calculated by dividing one acre (43,560 square feet) by the minimum lot size of % acre (10,890 sf)— is four units per acre. Isolated Waters Of All waters such as lakes, ponds, streams (including intermittent streams), farmed wetlands, and wetlands that are not under U.S. Army Corps of Engineers Jurisdiction. Impervious Surface: Any surface in the urban landscape that cannot effectively absorb or infiltrate rainfall. Land Trust: A non-profit, tax-exempt entity whose primary purpose includes the preservation of open space, natural land, rural land, or agricultural land, and which is permitted to hold conservation easements. Natural Area: An area of land, not necessarily undisturbed, which either retains or has been substantially restored to its original natural or native character. 80 Appendix A Definitions Natural Feature: An existing component of the landscape maintained as a part of the natural environment and having ecological value in contributing beneficially to air quality, erosion control, groundwater recharge, noise abatement, visual amenities, the natural diversity of plant and animal species, human recreation, reduction of cli- matic stress, and energy costs. Net Density: Density calculated by taking into account roadways, oversized lots, environmental constraints, etc. For example, if the lot size is '/ acre, then after deducting the above features, the NET density may be 3 to 3.2 dwelling units per acre. Open Space: An area that is intended to provide light and air. Open space may include, but is not limited to, meadows, wooded areas, and waterbodies. See also F�L-stricted Open Space. Perennial Stream: A natural waterway that contains water throughout the year except in severe drought. Private Street: A local private way which provides vehicular access to two or more residential structures that is not and will not be dedicated to public use, but which is owned and maintained by the Association. Project Boundary: The boundary defining the tract(s)of land that is included in a development project to meet the minimum required project area for a conservation development. The term "project boundary" shall also mean "development boundary". Public Improvement: Any roadway, sidewalk, pedestrian way, tree lawn, lot improvement, or other facility for which the local government may ultimately assume the responsibility for maintenance and operation, or that may affect an improvement for which responsibility by the local government is established. Restricted Open Space: Open space within a conservation development that is of sufficient size and shape to meet the minimum zoning requirements that is restricted from further development according to the provisions of this chapter. Setback: The required distance between a building and a lot line, street right-of-way, pavement, stream or river- bank, wetland or other delineated site feature. Special Service Area: Special service area (SSA) financing can be used to finance special services such as gen- eral property or natural area maintenance, free parking, snow removal from sidewalks, ambulance service, secu- rity, advertising and promotion activities and business attraction. Stream Bank or Ewer Bank: The ordinary high water mark of the stream or river, otherwise known as the bank- full stage of the stream or river channel. Indicators used in determining the bankfull stage may include changes in vegetation, slope or bank materials, evidence of scouring, and stain lines. Urban F lunoff Mitigation Plan: A plan that shall be required to be approved in connection with any new development. Walkway: A public way for pedestrian use only, which may or may not be located within the street right-of-way. Wetland: Wetlands are land that is inundated or saturated by surface or ground water at a frequency and dura- tion sufficient to support, under normal conditions, a prevalence of vegetation adapted for life in saturated soil conditions (known as hydrophytic vegetation). A wetland is identified based upon the three attributes: 1) hydrol- ogy, 2) soils, and 3)vegetation as mandated by the current Federal wetland determination methodology. 81 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual 82 Appendix B Determining the Allowable Density for Conservation Design Appendix B: Determining the Allowable Density for Conservation Design Note: The bulk of the information in this appendix was prepared by the Countryside Program; the informa- tion has been adapted for use by Illinois Communities. The Countryside Program is in the process of updat- ing the original materials. For the most current information, see the Countryside Program's web site, http://www.countrysideprogram.org. Determining the Allowable Density for Conservation Design Introduction Conservation design is an alternative form of land development. It is generally believed that in order to be accept- ed as a viable alternative, conservation design should be accomplished at "approximately the same density" as a similar conventional development. In fulfilling that objective, two issues need to be addresses: 1. What is"approximately the same density" and how is it established? and 2. Is a "density incentive" necessary to encourage property owners to utilize the conservation design option? Without a density incentive (i.e. the opportunity to develop more units that would otherwise be possible in a con- ventional subdivision), the property owner might choose to pursue the standard subdivision option and the advan- tages of utilizing conservation design techniques will be lost. This appendix discusses the methods of calculating densities and the merits and disadvantages of each method. Understanding Gross and Net Density "Density" is the term used to describe the number of dwellings that can be constructed on an acre of land. The permitted number of lots—or density—in a conventional development is based on lot size. The larger the required minimum lot size, the lower the density. However, considering lot size alone does not give a true indication of the actual densities that will likely occur. Three other factors need to be considered as well. First, an allowance must be made for roads. Second, in a typical conventional development, the size and shape of the site often results in some lots being larger than the required minimum size. Third, natural environmental constraints may further result in larger lots than the minimum required or dictate that portions of the site be set aside and not be part of a stan- dard subdivision lot. All of these factors reduce the project's density. For example, if the standard zoning requires a minimum lot size of one-quarter acre, the GROSS density — cal- culated by dividing one acre (43,560 square feet) by the minimum lot size of '/ acre (10,890 sf) — is four units per acre. However, when all factors are considered —roads, larger lots, and environmental constraints—the N ET density may be 3 to 3.2 dwelling units per acre. Depending on the extent of environmental constraints, the net density of a development may be considerably lower than the gross density. 83 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Key Issues and Recommendations When considering factors which influence whether the conservation design option will be utilized, the communi- ty should be aware that most property owners want to know up front, "How many units can I construct on the land?" An owner is not likely to spend time and money pursuing design alternatives without knowing the number of units permitted. Therefore, it is recommended that the community incorporate into its zoning regulations a spe- cific numerical or objective density standard. Several options are possible. 1.The gross density can be used (i.e. 1 unit/acre when the minimum lot size is one acre). This is, in effect, a bonus or incentive to the property owner, since the gross density is higher than the net density which can be achieved with a standard subdivision. Of all the options, it offers the greatest likelihood that the conserva- tion design option will be selected by the property owner over a standard subdivision. 2.The estimated net density can be used (i.e. .75 units!acre, or .80 units(acre when the standard lot size is one acre). This most closely approximates the net density or yield that will be achieved in a standard single- family subdivision. 3.The standard or net density method can be applied to the "net buildable area." In this option, areas with significant environmental limitations are deducted from the total project area. The density is then based on the net area available for development. Since this option requires subjective judgments on the part of the community, it should be considered with caution. In many instances, particularly when large lot sizes are required, a portion of the standard subdivison lot may actually be in an environmentally sensitive area. For example, rear lot lines may parallel a stream, or a rear yard may extend down a steep slope or into a wet- land. In these cases, the resource may be adequately protected, and the property owner continues to achieve the otherwise"net densities." If the resource areas are deducted prior to calculating the density, the property owner may be penalized and be permitted fewer units than can be achieved in the standard sub- division. In this option, the application of the conservation design option may be discouraged. On the other hand, on some properties, environmentally sensitive areas may be so large that the single-family sub- division results in significantly fewer lots than the calculated "net' density. Therefore, granting density credit for these areas could result in substantially more units than are achieved in a conventional subdivision. Determining a fair environmental reduction to remain density neutral is very subjective and may vary considerably from proj- ect to project based on the project's size, the minimum lot sizes required, and the characteristics of the environ- mental features. Experience has shown that the most reliable way to achieve "approximately the same density" in these cases where large environmentally sensitive features are present is to deduct the entire area of the feature(s) from the project area before calculating the number allowable units. This is especially important in cases where the conventional lot size is'/ acre or smaller. While these methods of calculation yield somewhat different densities, they are all consistent with the two funda- mental principles of conservation design: • That conservation design should occur at approximately the same density as a similar conventional development; and • That, from the community's perspective, conservation design should be viewed as a preferable method of development and, therefore, incentives should be offered so that this option is selected by property owners over a conventional subdivision. 84 Appendix B Determining the Allowable Density for Conservation Design The Yield Plan Some reference books advocate the use of a yield plan to determine the density for conservation design. The yield plan is a sketch subdivision that depicts how a parcel can be developed. It includes(most importantly) the number of lots that will fit on the site in compliance with the zoning and subdivision regulations. The yield plan becomes the basis for determining the equivalent number of units that can then be permitted in the alternative con- servation design. It unequivocally assures that conservation design is, in fact, density neutral. However, for several reasons, this approach for determining density is not recommended. First, it requires an investment by the property owner to create the yield plan. Second, since the investment has been to create the plan (and no more units are possible with conservation design), the owner may decide it is"easier to stick with the yield plan." Third, the yield plan is subjective and requires numerous judgments as to whether a lot is build- able and whether the subdivision has maximized preservation of natural features to the greatest extent possible. Ironing out these "details" and determining the final number of units requires considerable time and meetings between the property owner and the community even before the unit count for conservation design is known. This may be a disincentive for conservation design, since the property owner is spending considerable time and money just to determine the units permitted. Resources Arendt, Randall. 1994. Rural by Design: Maintaining Small Town Rural Character. Chicago, IL American Panning Association. Brandywine Conservancy, Environmental Management Center. 1995. Environmental Management Handbook, Vols One and Two. Chadds Ford, FA: Brandywine Conservancy. Meck, Stuart, and Kenneth Pearlman. 1997. Ohio Panning and Zoning Law. St. Paul, MN: Banks-Baldwin Law Publishing Co. —West Group. Originally Prepared By David Hartt, D.B. Hartt, Inc., Fanners, Cleveland, for The Countryside Program. (The original document has been modified for use by Illinois communities.) 85 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual 86 Appendix C Conservation Design Incentives Appendix C: Conservation Design Incentives Conservation Design Incentives Introduction The purpose of establishing a credit or bonus system is to provide incentive to developers, designers, builders, and municipal officials to implement better site design and locate new development in a manner that causes less impact to natural resources. The credit or bonus system may be related to the overall conservation development process or specifically to stormwater or impervious surface management. Examples Conservation Design Incentives 1. More Predictable Approval Process One of the best incentives for developers to design conservation developments is to increase the pre- dictability of the approval process. A process patterned after the conventional zoning process is preferable to one patterned after the Planned Unit Development (PUD) process. A community may wish to include one of these suggestions to clarify the approval process for conservation developments: • Create a list of design standards that, if included, will automatically get approval. • Incorporate a system similar to the Conservation Development Evaluation System (CeDES—Appendix C). A project's approval process will be predictable based on its CeDES rating. 2. Special Designations A community may provide incentives for which only conservation designs can qualify such as, eligibility for Special Service Area (SSA) designation (see Appendix D) 3. Density Bonuses If open space is dedicated to public use including, but not limited to, trails, parks, and other active recre- ation facilities, the developer may be eligible for a density bonus of up to X°/o. (Density bonuses also may be permitted for affordable housing, but that is a separate issue). 4. Impact Fee Reduction To the extent that conservation design reduces development impact, the municipality may consider reducing relevant impact fees. Example Stormwater Credits [Adapted from: The Stormwater Manager's Resource Center (2002). http://www.stormwatercenter.net/ (3 January 2003).] 87 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Stormwater credits may be tied directly to the Fecharge, Water Quality, Channel Protection, and Rood Control volume requirements. For example, if there is a detention volume requirement, then credits can be given for site design practices that reduce the volume of runoff generated by a site (e.g., establishing naturally vegetated con- servation areas). Site conditions also will determine which credits can be applied. For example, a stream buffer credit may not be implemented on upland sites with no perennial or intermittent streams. The following five options for stormwater credits can be applied within a community. Each community needs to select both stormwater sizing criteria and stormwater credits that best meet its economic, social, and resource pro- tection needs. In addition the specific numerical calculation of credits can vary. The credit can be expressed as a volume, or a fraction representing, for example, the fraction of the detention volume met by the credit. In all of the examples presented here, the credits are calculated as volumes that are based on the fraction of the total site area or site impervious area affected by the credit. . Channel protection and flood control credits are typically accounted for by adjusting hydrologic parameters. It is crucial that when an area is subtracted from the total site impervious cover resulting in requiring a smaller detention basin, that there be a mechanism to ensure that the technique is maintained in the long-term. Additional information, example calculations or applications, suggested criteria for implementation, and guidance on the best application for each credit can be found at http://www.stormwatercenter.net/ under "Manual/ Credits." The following lists specific design goals and possible credits: 1. Conservation Design Goals: • Preserve natural and recreational open space • Encourage more compact development to reduce the total impervious cover created on site. • Encourage the use of non-structural treatment measures to treat stormwater runoff on-site Credit: A density bonus may be permitted if certain criteria (such as the CeDES system) are met such as(to be defined by community): • Grass channels shall be used to convey runoff on at least X%of the road length (suggest 75%). • At least X%of the site area is conserved by a protective easement or other mechanism such as a natural conservation area (suggest 25%). • Fboftops and other impervious surfaces are disconnected or implement green rooftops. • A minimum of X%of the site area is preserved as open space (dependent on density of development). 2. Conservation of Natural Areas Goal: Encourage the preservation of natural areas and critical resources on site. Credit: Subtract conservation areas from total site area when computing detention volume. 88 Appendix C Conservation Design Incentives 3. Revegetation Goals: • Encourage revegetation of cleared areas with native plants • Encourage additional native vegetation for development in agricultural fields. Credit: A revegetation credit shall be applied where native vegetation is used to supplement existing vege- tative cover, or to compensate for areas cleared during development. The credit may be given by adjusting the pre-and post-development curve numbers. In order to receive credit, the following example criteria must be met: species used for revegetation shall be native to (Municipality) and selected from a list of approved species identified in the "Native Rant Guide for Streams and Stormwater Facilities," (N RCS et al). 4. Fboftop Disconnection Goal: Encourage the use of overland flow or infiltration areas to treat rooftop runoff. Credit: Disconnected rooftops are subtracted from the total site impervious cover as long as the runoff is infil- trated on-site. Note: The use of this credit should be accompanied with an educational program to ensure that disconnected areas are not "reconnected" by residents over time. 5. Green Rooftops Goal: Encourage the use of vegetated cover on rooftops to detain and treat rooftop runoff. Credit: Green rooftops are subtracted from the total site impervious cover. 89 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual 90 Appendix D Special Service Area Financing Appendix D: Speci a I Service Area Financing Special Service Area Financing (The bulk of this Appendix has been adapted from an Illinois Municipal League publication.) Introduction Special service area (SSA)financing can be used to finance special services such as general property or natural area maintenance, free parking, and/or snow removal from sidewalks. It also can be used for physical improve- ments such as parking lots or garages, streets and sidewalks, water and sewer facilities, landscaping, street fur- niture, decorative lighting, plazas, and outdoor malls. Special service area projects provide special improvements or services for a specific area of the municipality that does not have them and which derives benefits from them beyond any benefit those services or improvements might indirectly provide to the municipality as a whole. Special service area financing has been used extensively throughout Illinois. Special service area financing differs significantly from special assessment financing. In a special service area, all real estate is taxed at the same rate. This rate is based upon the equalized assessed value as are other local property taxes. In contrast, special assessment financing involves a court procedure and each property is assessed a payment individually based on expected benefits accruing to each property owner. A special service area tax may be imposed for an indefinite term and may be supplemented by other taxes authorized by the Illinois con- stitution or applicable state laws. Special Service Area Financing for Open Space Management Special service area funding can be used for open space management. There are two ways that this can be imple- mented. If the municipality or county takes management responsibility for the open space, then an active special service area can be created to generate funds to manage the open space. A more common implementation, however, is the use of a backup SSA. Communities often are concerned that the homeowners or other association designated to manage a conservation development open space will not main- tain this management over time. The financial responsibility for management will then fall to the local government, which may cause an economic hardship. A backup SSA can be created to ensure against this. The backup SSA will not impose any additional costs on landowners as long as the association is effectively managing the open space. However, if the open space is neglected or mismanaged, the SSA can be activated and the costs of the local government intervention will be covered by the special taxes imposed on the residents. 91 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Establishing a Special Service Area A major advantage of special service area financing is the ease with which it may be established. The steps in Illinois are as follows: 1.Determine the nature and scope of the project—the types of service(s) or improvement(s)to be made, their cost, who should share in the cost and the boundaries of the special service area. 2.Based on the project cost, determine the tax that will be required to finance the project. 3.Pass an ordinance proposing the special service area and hold a public hearing. 4.Wait 60 days during which time a petition may be filed to defeat the special service area proposal. If a petition is filed within this 60-day period that is signed by at least 51 percent of the electors residing in the special service area and by at least 51 percent of the property owners in the special service area, the pro- posal is defeated for a two year period. 5.After 60 days, if a petition with adequate signatures is not filed, an ordinance is passed officially creating the special service area, levying the special service area tax and implementing the project. The first two steps concerning the nature, cost, and financing of the project usually need to be undertaken with close cooperation between the local government and the affected taxpayers and/or property owners. The remain- der of the process involved in establishing the special service area is the responsibility of the local government. Language for implementing an SSA is included in the Model Ordinance Language for R-actice 7, Natural Area Management. 92 Appendix E CeDES System Appendix E: CeDES System CeDES System This system was created by The Conservation Fund as a tool for communities to use to review conservation devel- opments. It has been used in an awards program, as part of a community's plan review process, and as a method for developers to evaluate whether or not they are designing their developments with the appropriate components to protect the on-site and surrounding natural resources. It is included here as a tool to adapt and incorporate into a community's plan review process. It includes the evaluation of many of the goals and practices listed in this doc- ument. Conservation Development Evaluation System As public pressure on developers mounts to create more "environmentally friendly" developments, a tool is need- ed to encourage developers and communities to change development designs and to evaluate their effectiveness. The Conservation Development Evaluation System (CeDES) is a rating system created to evaluate a conservation development over the development's lifetime with an emphasis on the water quality and landscape impacts of the development. The purpose is to get developers to think about environmental concerns earlier in the planning process. CeDES looks at"conservation development" in the context of four specific areas: • site design and construction practices, • stormwater management, • preservation of open space, and • protection of natural resources. It does not address all of the issues which are important to make development more sustainable overall, although CeDES strongly supports this objective. For example, although they are not the focus of this evaluation system, the groups that developed CeDES favors infill and brownfield development, mixed-use, pedestrian-centered, or trans- portation efficient designs, as well as protection of cultural and scenic landscapes and rural character. The CeDES system is not intended to achieve these broader goals, but it does not preclude and can even help to advance them. CeDES was developed by The Conservation Fund in cooperation with members of the Conservation Development Alliance (see description below) and with input from many professionals skilled in planning and evaluating con- servation developments. The Conservation Development Alliance currently is being formed as part of this effort and to assist in regional workshops on conservation development. Fbtential partners include representatives from local, state, and federal government, national associations(e.g., National Association of Home Builders, Urban Land Institute), professional associations (e.g., American Society of Civil Engineers, American Planning Association), environmental groups, land owners, research institutions(e.g., The Center for Watershed Protection), and others. The CeDES evaluation will be maintained and updated by the Conservation Development Alliance. Ideally, local professionals, such as Soil and Water Conservation District (SW CD)staff, will be brought in to pro- vide an independent review of projects using CeDES. 93 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual CeDES is intended to provide a starting point and a tool that communities, developers, conservationists and con- sumers can use in evaluating "conservation" claims in terms of watershed and habitat protection. It is designed to provide a general evaluation system and should be customized for specific areas based on topography, soils, vege- tation types, and sensitive natural areas that are a priority to protect. Ideally, each criterion will be related to an accepted industry standard that also provides for differences in landscape setting, soils, vegetation, etc. The system is designed to be comprehensive in scope, yet simple in operation. Some important criteria are too site-specific to set general standards, such as vegetated buffers to protect surface waters and other sensitive features from impacts of development. Developers should be expected to design these important elements into their projects (e.g., minimum 50-ft. buffers along streams, lakes, and wetlands), CeDES is intended primarily for areas of the eastern and Midwestern U.S. not the and West, where water resource and land cover issues may differ substantially. This system is designed for rating new and existing developments. It is a feature-oriented system where points are awarded or deducted for satisfying a specified criterion. CeDES recognizes that in communities with already restrictive development standards some developments may not score as well. Further, the CeDES ratings are much more stringent than the norm for many typical developments. Therefore, even a "1-Leaf' rating should be consid- ered a step in the right direction. CeDES intent is to encourage developers to strive to meet these rigorous stan- dards and achieve multiple "leaf' ratings for their developments. Rating System Criteria Bigibility: All residential and commercial developments greater than 10 acres (sewered) and 20 acres (unsew- ered) are recommended for evaluation as a Conservation Development using CeDES. Compliance Criteria: For classification as a Conservation Development, applicants must satisfy all of the prereq- uisites and earn a certain number of points to attain specified Conservation Development classifications. Having satisfied the basic prerequisites of the program, the applicant development is then rated according to the scoring system listed below. Scoring: CeDES scoring system is based on the premise that developments always should meet certain basic stan- dards. =ositive points will be awarded to developments that employ practices that go beyond basic standards to minimize impacts on water quality and natural resources. Negative points will be assessed for aspects of devel- opments that do not meet basic standards. Examples of negative practices include encroachments into wetlands or 100-year floodplains with fill or structures, and regrading or developing on steep slopes(e.g., >10%, depend- ing on soil erodability). A total of 20 points are available under the Conservation Development Evaluation System with four categories of certification: Conservation Development for developments that earn 80%or greater (16 or more) of the available points. Conservation Development for developments that earn 60%or greater (12 or more) of the available points. Conservation Development for developments that earn 40% or greater (8 or more) of the available points. Conservation Development for developments that earn 20% or greater (4 or more) of the available points. 94 Appendix E CeDES System Please note: When reporting the scoring please include the following language: "This score was determined using The Conservation Fund's Conservation Development Evaluation System (CeDES)version 10.1.99. CeDES is meant as a planning tool and is not a formal certification. The scoring for this development project was not reviewed or approved by The Conservation Fund." The Conservation Fund's Conservation Development Evaluation System (CeDES) I. Overview of the System • Presents a method of evaluating Conservation Developments. • Fbcognizes the site-specificity of each development and limitations on planning and design. • Fblies on the development of a baseline ("0" score) to which to compare the proposed development. • Assumes that most developments being evaluated were somewhat disturbed or managed landscapes before development (e.g., agricultural land). • Is not intended for sites comprised entirely of undisturbed land or high-quality natural areas that require more rigorous protections. • Understands that each category may not apply to every development. • Emphasizes impact on water quality. II. Prerequisites Evidence that the site design process includes a review and analysis of the site's sensitive natural features and that the site plan reflects that review. One approach to this process is outlined in the Natural Lands Trust's "Growing Greener" approach (see attached). III. Core Criteria Each development will be judged on the following core criteria. Please circle the appropriate response. Use the comment section after each criterion to elaborate on your response, as appropriate. If a criterion does not apply, explain why. 1. Site Design and Construction Practices 1 a. Percent Impervious Surfaces Pblative to Conventional Development P,ationale: The greater the impervious surface percentage, the greater the amount and level of contami- nation of runoff and the lower the infiltration for natural replenishment of groundwater. This criterion also will be an indicator for the decrease in nutrient loadings, which have been proven to correlate well with percent impervious surfaces. Measurement: The percent decrease in street, sidewalk, and driveway surfaces compared to a conven- tional design for the site (e.g., based on national averages for conventional design: streets >22 ft. widths; cul-de-sacs> 40 ft. radius; sidewalks> 4 ft. width; driveways unshared between homes, and > 9 ft. one-lane or > 18 ft. two-lanes) 2. No decrease 0. Greater than 15%decrease +1. Greater than 35% decrease +2. Greater than 60%decrease X Does not apply Comments on site-specific constraints 95 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual 1 b. Preservation of Natural Features/Land Form Change Rationale: Generally, the less disturbance there is, the lower the impact of the project on water quality and natural resources. This criterion is intended to measure the disturbance of the land during construc- tion and encourages road and lot design to fit with the existing topography. Measurement: Relative levels of cutting and filling (It is understood that there may be sites where dredg- ing a siltedAn area would be beneficial). 2. Mass disturbance/grading, more than 80%of parcel being developed -1. Significant/ large contiguous areas of grading, 50-80%of parcel being developed 0. Minimum cut and fill, no large areas of grading +1. Grading less than 30%of parcel being developed; cut and fill depth and area minimized around structures or streets +2. Design and implementation of grading/cut& fill activities create minimum disturbance of natural land forms and least possible disturbance and compaction of soils X Does not apply Comments on site-specific constraints 1 c. Sediment and Erosion Control Pationale: Minimizing erosion and other sediment transport during and immediately after construction minimizes a major source of damage to water quality and watershed's ecological health. Measurement: Fblative use of sediment and erosion controls using strong local or region-specific soil ero- sion control manuals. (Note: Professionals with the National Resource Conservation Service (N RCS) or other local soil experts should be consulted to ensure that local regulations are strict enough to achieve the intent of the standards below, otherwise fewer points should be given for meeting less-stringent local control ordinances.) 2. No controls -1. Required construction erosion controls in place but failing 0. Required construction controls in place, monitored, and in compliance +1. Required construction controls exceeded +2. No measurable soil loss X Does not apply Comments on site-specific constraints 2. Stormwater Management 2a. Fdinoff Rate Rationale: Reducing the velocity of runoff from a development site, by retaining more on-site and allow- ing it to infiltrate, allows more runoff to infiltrate, and reduces erosion. Reduction in runoff rate may be attained by many methods including grass swales, buffers, reduction of impervious surfaces, etc.. Measurement: Rate of runoff as compared to immediately prior pre-development land-use conditionsfor the 10-year design storm using locally approved stormwater runoff models(e.g. IR55). Please provide support for your response. 96 Appendix E CeDES System 2. >15% increase in runoff rate -1. 0-15% increase in runoff rate 0. No increase in rate of runoff +1. 0-30%decrease in runoff rate +2. >30%decrease in runoff rate X Does not apply Comments on site-specific constraints 2b. Runoff Volume Rationale: Reducing the total volume of runoff from a development site, by retaining more on-site and allowing it to infiltrate, reduces erosion, sedimentation, and other impacts on surrounding bodies of water. Reduction in runoff volume may be attained by many methods including grass swales, buffers, reduction of impervious surfaces, on-ite detention, infiltration basins, etc.. Measurement: Volume of runoff as compared to immediately prior pre-development land-use conditions for the 2-year design storm using locally approved stormwater runoff models (e.g. TR55). Rease pro- vide support for your response. 2. >15% increase in runoff volume -1. 6-15% increase in runoff volume 0 0-5% increase volume of runoff +1. No increase in runoff volume +2. Decrease in runoff volume X Does not apply Comments on site-specific constraints 3. Open Space 3a. Management of Open Space Rationale: Generally, the more contiguous open space that is preserved in a natural state, the lower the project's impact on the ecosystem. Measurement: Ratio of open space adjusted for vegetation and management to total open space. Rease provide calculations with your response. Adjusted Open Space Ratio Den ity in units!ac Fbints > 4 >2 -4 >1 —2 0.5 - 1 < 0.5 2. 0-9% <15% 15-24% 2534% >40% -1. 10-14% 15-24% 25-34% 35-49% >50% 0. 15-24% 25-34% 35-49% 50-59% >60% +1. 25-30% 35-40% 50-55% 60-70% >70% +2. >30% >40% >55% >70% >80% X Does not apply 97 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Open space calculated as follows: (A X 0.2) + (B X 0.2) + (C X 0.5) + (D X 1.0) x 100 = Adjusted open space ratio E W here A = Acres of open space with managed landscape B = Acres of open space in agriculture with annual crops C = Acres of open space in agriculture with perennial crops D = Acres of open space with native habitat E= Total undeveloped acres of open space Example Development Your Development Total Site Acreage 50 acres Buildable Acreage 40 acres Built 15 acres 40 homes R-,maining buildable 25 acres (12 acres turf grass and acreage 13 acres restored native habitat Unbuildable acreage 1 10 acres flood lain, wetland, steep slopes) A = Managed 12 acres(turf grass and landscape non-native ornamentals B = Agriculture with 0 acres annual crops C = Agriculture with 0 acres perennial crops D = Native habitat 23 acres(10 unbuildable and 13 restored E= Total 35 acres(10 unbuildable and undeveloped acreage 25 buildable) Example Development: (12x0.2) + (0x0.2) + (0x0.5) + 23x1.0) x100 - 72.6% 35 Based on the project's 0.8-unit density per acre (40 homes= 50 acres), the adjusted open space ratio would earn a ranking of +2 using the table above. Your Development: (A X 0.2) + (B X 0.2) + (C X 0.5) + (D X 1.0) x 100 = adjusted open space ratio E Comments on site-specific constraints: 98 Appendix E CeDES System 3b. Environmentally Constrained Open Space Fationale: There should be no building, grading or clearing in certain sensitive areas including wetlands, floodplain, and steep slopes. A development that adequately protects such areas through easements and by designation as protected, undivided open space could receive a high score under this criterion. This criterion recognizes development that provides long-term protection of these sensitive areas through easements and other development restrictions. Measurement: relative percentages of environmentally constrained open space preserved, adjusted for degree of protection. Please provide calculations with your response. 2. < 50% -1. 51 —70% 0. 71 -80% +1. 81 —90%, +2. 91 — 100% X Does not apply Open space calculated as follows: (A X 0.5) + (B X 1.0) x 100 = Adjusted environmentally-constrained open space C W here A = Acres of environmentally-constrained open space undivided into lots(i.e., common open space) B= Acres of open space with permanent protection (e.g., conservation easement) C = Total acres of open space Example Development Given: The development has 5 acres of wetlands protected under a conservation easement, 3 acres with > 25% slope, and 2 acres of floodplain, for a total of 10 acres of environmentally constrained open space. All the wetlands and steep slopes are undeveloped but half of the floodplain is developed. Example Development Environmentally Open Space Open Space with Developed Constrained Fbsource (acres) Permanent (acres) Total Protection acres Wetlands 0 5 0 5 Flood lain 1 0 1 2 Steep slopes 3 0 0 3 Other 0 0 0 0 Total 4 5 1 10 Variable A B C 99 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual (4x0.5) + (5x1.0) x100 = 70% 10 the adjusted rating would be -1 because the steep slope areas were not protected by permanent con- servation easements and floodplain was partially developed. Your Development Environmentally Open Space Open Space with Developed Constrained Resource (acres) Permanent (acres) Total Protection acres Wetlands Rood lain Steep slopes Other Total Variable A B C (A x 0.5) + (B x 1.0) x 100 = Adjusted environmentally-constrained open space C Comments on site-specific constraints: 4. Protection of Natural Resources 4a. Development of Natural Resources Protection Plan Rationale: A site's entire set of resources needs to be considered holistically and protected in an inte- grated manner. Measurement: Degree of natural resource-based site planning and long-term protection 2. No natural resource inventory or management/ protection plan -1. Natural resource inventory conducted, but no significant linkage to site design 0. Natural resource inventory conducted, natural areas linked into continuous open space system +1. Natural resource inventory conducted, natural areas linked, permanent protection of natural areas/open spaces(e.g., easements) +2. Natural resource inventory conducted, natural areas linked, permanent protection of natural areas and adjacent open spaces(e.g., conservation easement), management/ protection plan in place, long-term management/ protection plan in place X Does not apply Comments on site-specific constraints: 100 Appendix E CeDES System 4b. Existing Vegetation: Tree and Native Rant Conservation Fbtionale: Generally, if mature trees or other native plants, such as prairie plants, are present on the site, preserving those plants lowers the impact of the project on local ecosystems. Measurement: Loss of mature trees or other native plants Re-Development Tree/ Native Rant Cover on Site Fbints 10-35% 35-50% 50-75% 75-100% 2. loss>10% loss>30% loss>50% loss>70% -1. loss 0-10% loss 2030% loss 30 50% loss 60 70% 0. no net loss loss 0 20% loss 10 30% loss 5050% +1. no absol. loss no net loss loss 0-10% loss 40 50% +2. no absol.loss and no absol.loss no net loss loss<40% additional planting X Does not apply Comments on site-specific constraints: 4c. Newly Ranted Vegetation: Other Landscaping Rationale: The amount and type of vegetation designed into a site's landscaping greatly influences the land's ability to catch, filter and infiltrate stormwater. Generally, the larger the percentage of native veg- etation on the site, the more positive the ecological and water quality benefits to the environment. Measurement: Use of different types of vegetation 2. Rant turf grass -1. Use of native vegetation only in buffer areas, turf grass and non-native landscaping elsewhere 0. Use of native vegetation in 50% of open space, turf grass and non-native landscaping elsewhere +1. Use of native vegetation in 50%of open space, turf grass and non-native landscaping elsewhere, and provision in homeowner's association rules to encourage the use of native vegetation on individual lots +2. Use of native vegetation greater than 50%in open spaces, and native vegetation encouraged or required in homeowner covenants/deed restrictions X Does not apply Comments on site-specific constraints: Total available points= 20 101 Northeastern Illinois Ranning Commission and Chicago Wilderness Conservation Design Resource Manual Development Example A 80-acre conservation development to be built on an old farm minimizes paved areas and reduces stormwater runoff. The proposed development also protects contiguous open space, but pays little attention to landscaping with native plants. The development scores 7 points (39%) under the CeDES evaluation system, earning it a to rating overall. Scoring on each criterion and the development's overall rating calculation are shown below: 1 a. Percent Impervious Surfaces Relative to Conventional Development = +1 (40%decrease in streets, sidewalks, and driveway surfaces compared to a conventional design for the site) 1 b. Reservation of Natural Features/ Land Form Change = +1 (Grading of less than 30% of parcel and cut and fill minimized) 1 c. Sediment and Erosion Control = +2 (No measurable soil loss) 2a. Stormwater Fdanoff Fete = +2 (>30%decrease in runoff rate) 2b. Stormwater Rinoff Volume = +1 (No increase in runoff volume) 3a. Buildable Open Space = +2 (See example on p. 6) 3b. Environmentally Constrained Open Space = -1 (See example on p. 8) 4a. Development of Natural Resources Protection Flan = 0 (Natural resource inventory conducted with linkage to site design) 4b. Existing Vegetation: Tree and Native Plant Conservation = X (no score) Does not apply: site was nearly entirely in use as a farm with few trees and no native vegetation with the exception of a small wetland 4c. Newly Planted Vegetation: Other Landscaping = -1 Use of native vegetation only in buffer areas, turf grass and non-native landscaping elsewhere Final calculation: 7 total points out of 18 possible (39 1/6)_ 4 Fbting (20 available points minus 2 points for 4b. which did not apply) 102 MULTI-USE OF STORMWATER DETENTION PONDS IN PARKS AND OPEN SPACES by PALLAVI SHASHANK SHINDE (Under the Direction of Bruce K. Ferguson) ABSTRACT Water possesses several qualities that contribute to positive aesthetic experience. But these qualities are rarely exploited in our cities. On one hand we treat water as an exciting element adorning our city squares in the form of fountains, while on the other hand is the merely functional drainage system. We overlook the possibility of utilizing stormwater for recreational and aesthestic purposes. The detention basins being designed today are still a single purpose facility. Some are rectangular boxes and look like mud holes in the ground, surrounded by fences. This thesis proposes a design that transforms such detention basins in the Southeast Clarke County Community Park, Athens, GA, into a multi-use amenity providing recreation, aesthetic value and wildlife habitat along with flood control. The design proposal exposes the flow of stormwater and brings people in contact with it,putting it back into the social consciousness of the urban society. The proposal illustrates that detention ponds do not have to be sterile and ugly but can be attractive and form sustainable systems. INDEX WORDS: Stormwater, detention,parks, open spaces, Southeast Clarke County Community Park, multiple-use, wetland. MULTI-USE OF STORMWATER DETENTION PONDS IN PARKS AND OPEN SPACES by PALLAVI SHASHANK SHINDE B. Arch, University of Bombay, India, 1997 A Thesis Submitted to the Graduate Faculty of The University of Georgia in Partial Fulfillment of the Requirements for the Degree MASTER OF LANDSCAPE ARCHITECTURE ATHENS, GEORGIA 2002 C 2002 Pallavi Shashank Shinde All Rights Reserved MULTI-USE OF STORMWATER DETENTION PONDS IN PARKS AND OPEN SPACES by PALLAVI SHASHANK SHINDE Major Professor: Bruce K. Ferguson Committee: Marianne Cramer Michael Tarrant Robby Bryant Electronic Version Approved: Maureen Grasso Dean of the Graduate School The University of Georgia December 2002 iv ACKNOWLEDGEMENTS I would like to thank Bruce Ferguson, my major professor, for his valuable guidance and advice, which helped me in realizing my ideas and goals for this thesis. Thank you to Marianne Cramer, Michael Tarrant and Robby Bryant, my reading committee, for their help, suggestions and time. I extend my gratitude to Kenneth Wright, president of Wright Water Engineers, Denver, Colorado, for providing information on Skyline Park; Jonathan Jones,vice-president, for supplying information related to my thesis concept. Special thanks to Frank Henning, of the University of Georgia Extension Services, for providing valuable information about the design application site; Walter Cook for offering his time and expertise to inventory the existing vegetation on site; Darrel Morrison, for his planting recommendations for the design proposal; and Eleonora Machado, for sharing her software expertise. Additional thanks to Donna Gabriel for helping me with the graduation formalities over the past few months. I would also like to express my appreciation to all my classmates for their companionship during my time at the University of Georgia. Thank you to all my professors, from whom I learnt a lot. I am thankful to my parents for guiding me to the profession of architecture, which led to landscape architecture. Also, thank you to my sister, for her love and support. And finally, thank you to my husband, Shashank Shinde, for his enormous encouragement, support, help and love. v TABLE OF CONTENTS Page ACKNOWLEDGEMENTS............................................................................................... iv CHAPTER 1 INTRODUCTION .............................................................................................1 2 STORMWATER MANAGEMENT..................................................................4 3 MULTI-USE DETENTION PONDS IN PARKS AND OPEN SPACES ......21 4 CASE STUDIES..............................................................................................42 5 DESIGN APPLICATION................................................................................56 SELECTED BIBLIOGRAPHY.........................................................................................88 1 CHAPTER ONE INTRODUCTION The everyday increase in the impervious and contaminated surfaces of the urban landscapes is resulting in severe floods and degraded waterways. This has led to an increased number of studies on stormwater. Many municipalities have adopted a dual approach to stormwater management that incorporates flood control and water quality improvement. This approach still fails to address broader needs of the community such as recreation and aesthetic enjoyment. Though water forms an important element of our landscapes in the form of streams, lakes, ponds, fountains and cascades, we too often overlook the possibility of utilizing stormwater for recreational and aesthetic purpose. An integrated approach should not only address the dual-purpose approach, but also aim at making the system a part of the community. This would have a positive impact on life in urban areas. Impacts of urbanization Urbanization is replacing pervious ground cover and resulting in compacted soil. This allows only a small amount of water to infiltrate into the ground. The rate of runoff in urban areas is high due to the absence of vegetation or depressions that could have held and delayed the runoff. As runoff gains volume and speed, the flow becomes strong enough to transport materials, damage property and degrade streams. Chemicals and biological pollutants are discovered in urban stormwater, resulting from automobile greases and oils. The result is contamination of our streams and rivers, and adverse effects on aquatic flora and fauna. 2 The potential for integration In response to the federal guidelines and growing awareness, efforts are made to detain stormwater. These usually take the form of detention ponds or structures in open spaces that are sometimes covered or fenced off and are considered an eye sore. They are often not very popular within communities. It is beneficial to make the hydrological system a part of the space not just physically but also socially. Stormwater if treated in an appropriate way can provide amenities in communities, especially when it is incorporated in open space and recreation grounds. It can have multiple functions like water quality enhancement, wildlife habitat and flood control while providing aesthetic value and community recreation. Thesis intent The intent of this thesis is to study the new integrated approaches to the urban stormwater problem used by a selected group of designers and to apply this knowledge to a site in Athens, Georgia. This thesis explores the possibility of a stormwater detention facility as a multiuse facility in parks and open spaces. In the process this thesis sheds light on the following questions, • Why is there a need to make a detention pond a multiuse facility? • What are the benefits of making a detention pond a multi-use facility? • Can recreational amenities be successfully incorporated with the functional needs of stormwater? If yes, then what kind of recreational facilities can be incorporated? • What kind of maintenance is required for such a system? • Can there be a problem with the toxic materials in stormwater from the urban areas on vegetation, water, soil and wildlife? • What are the safety concerns? 3 ■ What are the general planning considerations to make a detention facility into a recreational amenity? Structure of the following chapters Chapter two examines the importance of water in our landscapes, its symbolism and qualities, the impact of urbanization on the watersheds and the subsequent stormwater issues. It explores conventional and alternative methods of stormwater management. Chapter three deals with incorporation of stormwater detention facilities into parks and open spaces as multi-use facilities and the issues related to it. Chapter four presents, in detail, the case studies of Mill Creek Park in King County, Washington, Fishtrap Creek in Abbotsford, British Columbia and Skyline Park in Denver, Colorado. Chapter five applies the knowledge from the previous chapters to a site in Athens, Georgia. The design intent is to address the flood problem and water quality issues while providing recreation for the community, habitat for wildlife and aesthetic pleasure. 4 CHAPTER TWO STORMWATER MANAGEMENT Water in landscapes Water is life itself- the magical element that connects all creation. It is the magnet and mirror of life and genesis of settlement. Throughout history man has utilized it for various utilitarian, recreational and aesthetic purposes. Through sight and sound water enriches the place and its surroundings, whether in a city or in the wilderness. Everyday life can be enriched through sensitive relationship with water (Litton, Tetlow, Sorensen and Betty, 1974, 1-2). Water offers a primal attraction and provides an elemental form of open space and high contrast relief from the city (Don, 1980, 43). It has the potential to forge an emotional link between man and nature in the city (Spiro, 1984, 142). Symbolism of water Water is a cooler, quencher and cleanser. It symbolizes life, purity, power, timelessness, refreshment, wildness, unpredictability and solace in hospitable surroundings. Blue water suggests coolness while white water suggests roaring power and sound (Litton, Tetlow, Sorensen and Betty, 1974, 4, 297). In the eastern philosophy, water is regarded as one of the five forces of the earth. Qualities of water "Water is not just a vital element in our lives; it can also be experienced in a whole variety of ways. It creates different kinds of atmosphere and mood that appeal to our feelings." -Robert Woodward, Waterscapes, 2001, 12 5 Water possesses several qualities that can contribute to positive aesthetic experience. Following are some of these qualities of water. Sound: The sound of water can be powerful as the roar of the ocean or gentle as the gurgle of a small stream. Sound of water allows people to connect to nature, refresh spent minds or block out less desirable noises (Moore, 1995, 26). This quality has been exploited since ancient times by the use of water fountains and cascades in gardens, plazas and palaces. The sound of water is manipulated in musical fountains, where water is the artist; the fountain is the musical instrument (Dreiseitl, 2001, 40). Water's sound has all the characteristics of music, variety of volume and pitch, sharpness and softness, rhythm and harmony (Woodward, 2001, 13). Touch: Water touching our skin is the most personally intimate experience we can have of it (Moore, 1995, 27). This quality of water entices us to walk along the shores in ankle deep water, to play in the streams, to take part in water sports and to be thrilled at water amusement parks. Emotional contact with water occurs when people are allowed to get close without actually touching it, resulting in our 'mental leaning out over' (Moore, 1995, 27). Movement: Movement is the most exciting and vivid quality associated with water. It may be gravity descent, wind driven or forced movement. Chutes, cascades, boils, rollers, rapids and ripples are some of the falling and turbulent forms of water (Litton, Tetlow, Sorensen and Betty, 1974, 79). Water running in channels acts as a unifying element, linking spaces and providing continuity (Moore, 1995, 23). Stillness: Still water instills peace of mind. Stillness of water symbolizes sacredness and serene dignity (Moore, 1995, 27). Transparency: Transparency imparts depth to water. Light is absorbed as it passes through the medium, facilitating glimpses of the aquatic world below. Reflection: Water can be described as nature's mirror of the landscape (Litton, Tetlow, 6 � y E AJ IL Figure 2.1 Taj Mahal,Agra, India (http://www.allindiatravels.com/gifs/taj -mahal) Sorensen and Betty, 1974, 79). Sometimes the gentlest light from the moon accentuates mysticism. The intensity of light creates varied moods in people - from depressed to delighted. Reflective water adds an element of fantasy to architecture by filling shadows with light (Moore, 1995, 26). This quality of water has been used in Islamic gardens, where a large pool is built in front of a monument to produce its reflection; e.g., The Taj Mahal (Figure 2.1). Reflective water idealizes the places we build to symbolize the Gods we worship, the heroes we intend to remember or the ideals we cherish (Moore, 1995, 26) Color: Water in nature is rarely colorless. It is often stained with vegetative stains or colored with suspended clay particles. Most color we see in water is from the reflection of the surrounding or from underwater objects seen from its transparent body (Woodward, 2001, 13). These qualities of water are seldom fully exploited in cities. On one hand we treat water as an exciting element adorning city squares in the form of fountains while on the other hand is the merely functional drainage system buried underground, far from the eyes of the people. Rapid urbanization has altered our perception of water. 7 Evapotranspiraticn Precipitation IODY8 40% Surface ran-Off 10% lAk G roundwater Undeveloped Land �Vr'p Evapotranspiration Precipitation ff1D o 26% 13% 30%, I Y Storm sewer a Fun-off 431 Developed Land Groundwater 32'Y Figure 2.2 Impact of impervious surfaces (Hough, 1994, 39) Impacts of urbanization In nature when precipitation occurs, 50% of it is absorbed by the soil and vegetation and the rest is evaporated or transpired back into the atmosphere or carried over the land as surface runoff. Infiltration replenishes the ground aquifers thereby securing our supply of fresh water. Vegetated soils and woodlands provide storage by trapping and percolating water through the ground with minimum runoff and maximum benefit to the ground water recharge. Natural flood plains and lakes act as storage reservoirs for rivers that further reduce the magnitude of peaks down stream by spreading flows over a longer period of time. Nature takes care of itself, replenishing life forms and rejuvenating the landscape, forming a sustainable ecosystem. 8 With the advent of urbanization, the vegetation is cleared, land is graded, floodplains may be occupied and a waterproof seal covers the land.Asphalt and concrete replace the soil, buildings replace the trees and catch basins and storm sewers replace the natural streams (Hough, 1994, 39) (Figure 2.2). The meandering streams are straightened and now run in concrete channels. The streams of the pre-city landscape have vanished from modern maps. Old streams still flow through the city, buried beneath the ground in large pipes. They are invisible, but their potential contribution to downstream floods is nevertheless unabated and magnified (Spirn, 1984, 130). The hydrological cycle is a water balance that accounts for the endless circulation of the earth's water. It is vital for sustaining life and necessary to maintain human food resources and social values (Wanielista and Yousef, 1993, 4). Urbanization has altered this hydrological cycle. The natural hydrological cycle is short-circuited by water diversions, artificial storage in reservoirs and urban piped supply streams. The absence of vegetation and pervious soil creates greater runoff, extreme floods and low ground water table. Floods account for more property damage in the United States than any other single natural hazard. Floods increase in magnitude and destructiveness with each increment of urban growth; urbanization can increase the mean annual flood by as much as six times (Spirn, 1984, 129-130). Another impact of urbanization is the degradation of water quality. The EPA's National Urban Runoff Program (NURP) established that in many cases the first flush of stormwater in an urban area might have the level of contamination higher than that normally present in sewage wastewater. This is primarily due to the tendency of the initial stormwater flow to pick up and transport much of the deposited vehicular, animal and human detritus from pavement (Campbell and Ogden, 1999, 123). Toxic chemicals are a by-product of modern industrial processes, agricultural practices and fuel consumption. These toxic chemicals enter the streams, rivers and lakes through storm 9 runoff(Spirn, 1984, 136).Algae growth causes taste and odor problems in drinking water supplies and reduces recreational value of lakes and fundamentally alters its biological balance (Logan and Yaksich, 1990, 26). Every rainfall sweeps dirt and debris of the city streets into storm sewers and with it, heavy metals and other toxic materials such as oil and grease. Pollutants from roads, paved surfaces and rooftops include a range of organic and chemical compounds and heat from paved surfaces, making urban stormwater hostile to aquatic life (Hough, 1994, 78). In nature sediment from gradually meandering stream bank builds point bars and aquatic habitats. In urban areas, the excess sediment in suspension makes water turbid, inhibiting plant growth and reducing species diversity. On settling at the bottom, excess sediment destroys spawning beds and habitats of bottom dwelling biota that depend on the interstices of sand and gravel particles for their habitat (Ferguson, 1998, 7). Turbidity and warmer temperatures, increase of nutrient and salts, and loss of dissolved oxygen further degrade the water quality in urban rivers, streams and lakes. Conventional stormwater management practices Conveyance has been the conventional method of dealing with stormwater. It owes its origin to the urban sanitation movement of the nineteenth century. The specter of water borne disease, which haunted cities in the past was laid off by the conveyance i Figure 2.3 Conveyance (Ferguson, 1998, 41) 10 system. Conveyance is the moving of surface runoff from one place to another by a network of pipes, channels, swales and culverts draining into one another, until runoff disappears from the site (Ferguson, 1998, 40) (Figure 2.3). The pipes are usually buried underground and the surface of the conveyance system is essentially impervious. Problems with the conventional system The benefits of conventional stormwater design - well drained streets and civic spaces is paid for by the environmental costs of eroded streams, flooding, and impairment of water quality and aquatic life in downstream water courses. Gutters, curbs and drains collect rainfall and direct it to sewers, which transport it rapidly to streams and lakes. Storm sewers transport water from one point to another, merely changing its location and not reducing or eliminating water. As urban storm drainage system drains water efficiently from roofs, streets and sidewalks, the flood control system must be continually augmented to prevent flooding downstream (Spirn, 1984, 131-132). The impervious system provides no scope for infiltration of water thereby reducing the ground water recharge. The system also separates urban society from environmental values that embrace both the city and the land. The natural processes are hidden away; buried underground far from the eyes of city dwellers. Conventional system fails to recognize the potential of stormwater as an environmental resource. The present problems associated with conventional stormwater management have promoted research and alternative methods have been explored in recent years. Alternative stormwater management methods The detrimental effects of stormwater runoff have prompted many municipalities to pass regulations that require that post-development runoff peak volumes and water 11 .......... Figure 2.4 Detention (Ferguson, 1998, 41) quality not exceed pre-development levels. This measure focuses on capturing stormwater on-site, immediately after rainfall and releasing it slowly at controlled rates downstream or allowing it to infiltrate back into the soil. It is achieved by detention, extended detention, infiltration and rainwater harvesting. Detention Detention is the slowing down of surface flows as they move over the ground (Figure 2.4). Its purpose is to suppress downstream flooding and erosion by reducing the rate of flow (Ferguson, 1998, 41). Urban detention was started in the 1960's when it was discovered that development is followed by increase in storm runoff and aggravated flood damage (Ferguson, 1998, 149). The main aim of detention is to control the peak rate of runoff. The basic elements of a detention facility are an inlet, a storage basin and a constricted outlet. There can be multiple inlets. A secondary overflow or emergency spillway is necessary to allow water to pass, if it exceeds the capacity of the basin. This can be in the form of earthen channels excavated on the sides of the dam or large weirs, higher than the principal outlet. The principal outlet can also be designed to act as emergency spillway. The detention storage is the volume of the reservoir above the outlet's invert elevation. In a dry basin the outlet is flushed to the basin's floor. It drains completely after a few hours of the flood event (Ferguson, 12 Additnal maximum safety storage-�---�- ------ Emergency spillway -------------�-- ------ - Detention(tkwd)atoregsTraeFr r�k Permanent Pool po a.tlrain _ Fi urg e 2.5 Extended Detention (Ferguson, 1998, 182) 1998, 150). Detention facility can be of two types depending on its proximity to the water source - source control (on-site) and downstream control (regional) (Stahre and Urbonas, 1990). Extended detention Extended detention stores water for a longer period of time thereby improving the quality of water. The extended detention basins can be dry or wet. The dry extended basin drains water completely like a dry detention basin but additionally contributing to water quality enhancement. In a wet basin the outlet is raised creating a permanent pool of water (Figure 2.5). Due to the extended period of detention, suspended particles settle out, chemicals get absorbed in the bottom sediment or by biota and biodegraded (Ferguson, 1998, 42). The permanent pools can be deep open ponds, shallow vegetated ponds or wetlands. The residence time of water is a crucial factor when designing an extended detention basin. This kind of basin is generally used for small frequent storms since design for a large storm would increase the basin size and subsequently the cost out of proportion. Water quality treatment is adequate when designed for small storms (Ferguson, 1998, 167). A consideration in a wet pond is the sediment. The pond must be designed for sediment storage. In a typical urban watershed with stable land use, 13 Playing surface Filter fabric Aggregate fill Perforated pipe f i ` Y i Inflllratforo Figure 2.6 Subsurface infiltration (Ferguson, 1998, 213) sediment storage volume of half-inch runoff may allow sediment removal once every twenty years (Ferguson, 1998, 179). Infiltration Infiltration captures runoff and allows it to soak into the ground in closed basins. Infiltration restores ground water to the earth in addition to addressing the flood problem. The soil acts as a powerful filter. Only a few inches of soil can trap and accumulate oils, metals and nutrients thereby protecting the aquifer from urban contamination (Ferguson, 1998, 195). The floors and sides of an infiltration basin must be densely vegetated to create a porous soil structure and to prevent raindrop impact. An infiltration basin requires an overflow to drain excess water. Most infiltration basins are dry. Where basins are excavated to intersect the water table, a permanent pool is formed. The runoff temporarily fills the basin and infiltrates through the sides (Ferguson, 1998, 207). Infiltration reduces and in some cases completely eliminates the need for primary conveyance downstream thereby saving a lot of cost. In urban areas where space is limited, infiltration basins can be constructed below ground, leaving the surface for other uses like parking. Open graded aggregate is 14 ^cF-_ r Figure 2.7 Bioswale (Thompson and Sorvig, 2000, 154) used to create storage in subsurface basins. Perforated pipe, which is covered with aggregate and wrapped with filter fabric, is used in subsurface basins (Ferguson, 1998, 212) (Figure 2.6). Nowadays, different kinds of porous pavements are available to aid infiltration. Vegetated swales referred to, as 'Bioswales' are another way of facilitating infiltration. These swales store runoff while conveying it downstream at a low velocity providing biophysical treatment and infiltration. Weirs or check dams facilitate ponding of water and help to slow down runoff.A raised outlet at the lowest point along the swale provides overflow for excess runoff(Figure 2.7). Swales can be used along streets, replacing curbs and gutters (Ferguson, 1998, 123). Another concept, 'Rain garden' is also gaining popularity. A rain garden is a small-scale infiltration device that provides benefits of groundwater recharge, beauty and wildlife habitat. Rain gardens are 2 to 6 inches deep infiltration areas planted with native species. Runoff is captured in these depressions. The plants and soil filter pollutants in the stormwater allowing cleansed water to recharge the ground. These gardens can fit in small spaces like traffic islands and parking lots. Roads can be 15 Figure 2.8 Wenk and Associates Office Garden (Gregg and Wenk, 1998, 25) designed without curbs, allowing water to flow overland, further increasing infiltration and eliminating the cost of curb and gutter (Russell, 2000, 24). An example of rain garden is the design by William Wenk at his office building in Denver, Colorado (Figure 2.8). The design captures all roof runoff water from the building and provides controlled distribution to water landscape plants carefully selected and placed in a sequence of moisture requirements ranging from high to low, each area allowing infiltration into the ground. The site creates virtually no runoff. The downspouts used to convey water from the roof to the landscape also form a striking visual element (Campbell and Ogden, 1999, 136). Water Harvesting Water harvesting is the collection and storage of rainwater from roofs, paved surfaces and the landscape. Harvested rainwater can be used for various utilitarian purposes, irrigation, recreation, drinking or as a visual element in the landscape. Water harvesting is common in Australia and the Caribbean islands. Harvesting from a ground 16 �:11 Ow--M keg _7 _ Wk AA M Figure Pipes used for underground detention and infiltration (Tilton, 2002, 41) surface catchment area has a longer history. Ancient Israelites, Chinese, Pueblo, Australians and other Indians of the American southwest have used such water harvesting systems to survive (Thompson and Sorvig, 2000, 154). In United States, in the nineteenth and early twentieth centuries, small concrete cisterns were common storage structures serving families settling the high plains. The systems ranged from large civic infrastructures to small cisterns for individual homes. Underground stormwater management system Recently stormwater detention and infiltration are being facilitated by underground pipes (Figure 2.9). Runoff is directed into large reinforced concrete, steel or polyethylene pipes buried below parking lots and paved surfaces. The system is being used in new developments because it leaves the surface free for other uses. 17 Entering detention basin from developed drainage area c 0 0 m to (x Leaving basin Time,hour Figure 2.10 Effect of detention basin on a storm hydrograph (Ferguson, 1998, 150) Evaluation of alternative methods Detention and Extended Detention Almost all state and local governments require developers to reduce peak stormwater discharge to its pre-development level. To comply with this regulation, a detention pond is built on every development site.A detention basin considered in isolation, reduces the peak rate of flow but uniform on-site detention practiced in a large watershed can have a negative impact. A detention basin does not eliminate the runoff, it only delays it. The total volume of discharge from a detention pond is the same as the inflow but the discharge is delayed with a lower peak and elongated flow period (Figure 2.10). When the flows from different tributaries join downstream, the result is a peak rate greater than the pre-development peaks and possibly even greater than the developed watershed would produce without the basins. According to Debo (1982) randomly sited detention ponds cause concentrated discharge and increased flood peaks. They fail to control floods smaller than those of the design storm. Detention basins can reduce flood peaks if they are selectively located.A proposed detention basin should be evaluated on a site-by-site basis. In this scenario regional detention basins can sometimes work best. Municipalities can collect 18 Al k, X. Figure 2.11 Detention pond in a commercial area in Athens, Georgia (Photographed by author) stormwater impact fees from developers and use them to construct regional detention basins (Ferguson, 1991, 76). Extended detention can be effective in treating surface water quality but fails to address volume of runoff, groundwater recharge or water conservation (Ferguson, 1998, 42). A shortcoming of dry extended detention is its inability to treat the "first flush", which tends to be highly polluted. The residence time in a dry extended basin is too short for the pollutants to settle (Ferguson, 1998, 172). Wet extended detention has advantages over dry detention. It is effective in treating the "first flush". Due to the longer residence time, it continues settling and biochemical decomposition of pollutants. However, it is difficult to achieve sediment trap efficiency higher than 80% even in the most favorable ponds (Ferguson, 1998, 176-177). Too many detention basins being designed today have a very functional approach. Some are rectangular boxes and look like mud holes in the ground surrounded by fences (Figure 2.11). The potential of these basins to become a multi- functional element in the landscape is hampered. 19 Infiltration An infiltration basin is the only structural management practice that reduces both the peak flow rate and the volume of runoff from developed landscapes. By allowing the soil to absorb runoff, it diminishes erosion and flooding problems and supports groundwater recharge (MacElroy and Winterbottom, 2000, 52). Ferguson describes infiltration as environmentally the most complete solution to the problem of urban runoff. Infiltration, unlike detention, is recommended in numerous small upland basins or swales at the source of urban runoff. It gives the advantage of water traveling through the subsurface before discharging into streams. This aids in the filtration of water (Ferguson, 1991, 79). Some places like Long Island, Maryland and Florida have rigorously implemented infiltration technique to tackle development runoff. Underground detention system Underground stormwater systems present fewer public hazards than open ponds, don't present aesthetic challenges and do not compete for surface acreage (Tilton, 2002, 41). This system is suitable for high-density urban areas where allotting a space for detention ponds is almost impossible. However, the main problem with this system is that it is an 'out of sight' and 'out of mind' approach. It is a purely technical solution, which does not provide any wildlife habitat, aesthetic pleasure or public involvement that a surface detention pond could offer. The construction and maintenance cost can be high depending on the amount of runoff to be treated. A full and clogged underground stormwater system is difficult to see and therefore regular inspection and maintenance are required (Northcutt, 2001, 3, 10). Due to these concerns it is best to use surface ponds and basins where space permits (Northcutt, 201, 16). 20 Conclusion Some of the alternative stormwater management practices such as extended detention, infiltration and water harvesting, offer a better chance for managing the urban runoff than conveyance. The various benefits include groundwater recharge, water quality enhancement, flood control and wildlife habitat. Water harvesting reuses the stormwater reducing the load on municipal supplies and eliminating the need for conveyance downstream. But there is still a lack of public participation in and awareness of these facilities. The facilities are still predominantly designed for single use and are located in remote places representing a missed opportunity to design them for multiple uses such as recreation. They are often neglected due to the lack of public awareness. The aesthetic potential of such facilities needs to be exploited. There is a need for a design language that makes the most of available opportunities, one that re-establishes the concept of multi-functional, productive and working landscape that integrates ecology, people and economy (Hough, 1994, 31). The following chapter explores this multi-use potential of detention facilities in parks and open spaces. 21 CHAPTER THREE MULTI-USE DETENTION PONDS IN PARKS AND OPEN SPACES Need to expose the natural process of stormwater City development patterns have evolved. Cities no longer grow around rivers, cataracts, springs, pools and ports, but around airports or highways, in amorphous patterns that defy the presence of water and yet demand it all the same (Betsky, 1995, 13). We are forgetting how fundamental the vast systems of extraction, purification, distribution and drainage are to our urban life. There is little or no trace of it in our man-made environment. When we have to see water, we make trips to dams, the coasts and aquariums (Betsky, 1995, 13). Today's water is becoming increasingly domesticated and decreasingly appreciated. Modern treatment plants have replaced the natural water cycle with a mechanized hydrological cycle. The water supply and disposal systems today leave no indication that the water supplied to our tap has its origin to the rain falling on the roof tops and paved surfaces. Many of us have grown accustomed to taking fresh clean water for granted (Moore, 1995, 23). The urban environment today isolates us from the natural processes that support life. Much of our daily existence is spent in the surroundings that conceal the natural processes. The curb and catch basin that make rainwater disappear without trace below ground cut the visible links with natural water cycle. We are unaware of the ecological damage being done to the receiving waters (Hough, 1994, 30). The abundance and security of water supply has led to the perception of water as a free commodity and an infinite resource. The recent drought situation in southeast United States and some other parts of the world now questions the infinity of this resource. This situation coupled 22 with the ever-increasing water charges are a valid indication that we have been getting it very wrong, and that a complete rethink is now needed (Jones, 1995, 17). This can only take place by changing the public perception of water and increased environmental consciousness. Making the processes visible is an essential component of environmental education, which can be brought about by constant and direct experience assimilated through daily exposure and interaction with the place one lives in (Hough, 1994, 24, 31). Exposing the flow of water - where it comes from, how and where it is used, where it is treated and released, and the seasonal variation will help people in understanding the hydrological cycle and influence them to conserve water. Incorporating multi-use detention ponds in parks and open spaces With the growing human population, land is becoming scarce. McHarg noted that, "Urbanization proceeds by increasing the density within and extending the periphery, always at the expense of open space. As a result, unlike other facilities, open space is the most abundant where people are the scarcest." In cities it is difficult to hold stormwater due to limited space. In such situations it makes sense to design landscapes for multiple uses. Multiple-use can help in conserving space. There is a need to change our aesthetic conventions that have created a landscape of parks and playgrounds whose character rests on uniform application of cultivated turf and whose sole purpose is recreation (Hough, 194, 13). Instead of assigning recreation as the exclusive use of parks, parks can be designed to serve as temporary storage areas that can fulfill hydrological roles. Open spaces can thus become spaces for restoring the damage done by urban development rather than passive recreational space. Skillful planning can provide play and sun bathing areas in basins when weather is dry, as they will not be used for this purpose when it is raining anyway (Dreiseitl, 23 2001, 43). The land thus serves dual purpose, assisting hydrological functions but providing space for other uses. Golf courses, playing fields and parks are some of the landscapes where management could accommodate compatible uses (Hough, 1994, 79). Multi-purpose open spaces can define the shape of future growth, rather than vice versa. Online detention facilities, which pass the entire flood through them, are well suited for joint uses such as open space, wetlands and wildlife habitat that can tolerate frequent inundations. Off-line detention facilities, which bypass the frequent flows and allow only the excess flow into the detention area are well suited for intensive recreational uses such as playgrounds and play fields since they are flooded less frequently (DeGroot and Lloyd, 1992, 20). The uses can be combined at the time of development or could be retrofitted, either putting detention into an existing park or putting recreational facilities into an existing detention facility. If done well, the facilities become an asset to the community (DeGroot and Lloyd, 1992, 19). In order for natural processes to be appreciated and maintained by people, human intention and care for land must be evident (Nassauer, 1995). Thus by placing stormwater systems right in the heart of the city in parks and open spaces, there are better chances of it being noticed and therefore cared for by the people. Benefits of multi-use detention ponds Economic benefit Local governments are facing demands for services like parks, open spaces, recreation, drainage and flood control; increasing mandates from federal and state government and limited revenues to meet these demands. In such situation multiple-use can provide economic and political advantages. It increases the beneficiaries of the project and therefore makes administrative allocation of funds more justifiable. It also 24 ,x Fi rgu e 3.1 Detention pond in a Housing Complex, Indianapolis (Photographed by author) spreads the cost of land, design, construction and maintenance among more agencies (DeGroot & Lloyd, 1992, 20). Increased property values It has been noted that stormwater ponds and wetlands raise property values where they have been integrated into communities. Communities derive more property values when houses are fronted on stormwater ponds. Residents are willing to pay more for the maintenance and upkeep if they are provided access to these ponds and can utilize the recreational facilities located on the lakeshore (Ferguson, 1998, 14). Communities often resist single purpose storage facilities while multi-purpose facilities featuring parks, open spaces and recreation generally receive strong community support (Wright, 1982, 292). Figure 3.1 shows a detention pond in a housing complex in Indianapolis. The pond is provided with a deck, a shelter and picnic tables along the edge. It forms an integral part of the community and is extensively used for picnicking, fishing, bird watching or just hanging around. 25 Figure 3.2 Wildlfe in a detention pond, Indiannapolis (Photographed by author) Wildlife habitat There is evidence that people living in metropolitan areas have a genuine interest in wildlife and in opportunities to view wildlife (Figure 3.2). It was discovered in a survey of children aged six to ten that fifty percent of their outdoor activities involved wildlife (e.g., observing, collecting) and that children unlike adults were more interested in "creepy-crawly" varieties such as amphibians, reptiles and insects. Research has also indicated that contact with plants and animals is therapeutic and enriches the lives of elderly people and others requiring specialized care (Campbell and Ogden, 1999, 191-192). Many wildlife habitats are destroyed by urbanization. Detention ponds provide an opportunity to replace these habitats. Created wetlands can provide a number of aquatic and terrestrial habitats with opportunity for photography and nature study. Birds are particularly important for urban wildlife observers, many of whom are unable to travel long distances to see wildlife (Adams, Leedy and Franklin, 1982, 384, 386).A survey of the residents of Columbia, Maryland indicated that residents preferred future stormwater ponds to be managed for wildlife in addition to flood and sediment control. 26 There is also a movement within the golf course development industry to incorporate a wide variety of vegetation to create wildlife habitat (Campbell and Ogden, 1999, 191- 192). If designed well stormwater detention can serve as an amenity and be compatible with other park uses. It can provide a creative and practical alternative to traditional site development practices. Review of multi-use detention ponds One of the earliest examples of multi-use detention in a park is Boston's `Emerald Necklace'park system, designed by Frederick Law Olmsted (Figure 3.3). Olmsted created the Fens and the riverway to combat the flooding and pollution problems of Boston's Back Bay tidal flats (Spiro, 1984, 147). Originally a muddy and foul smelling area, he converted it into an idealized stream and salt marsh meadow with a park-like setting (Tucker, 2001, 36) (Figure 3.4). It was a brilliant multi-functional design with bridle paths, walkways, canoeing and park drives in addition to sanitary and flood control feature (Tunny, 2002). Olmsted forged a role for urban parks, which was bound in the alleviation of the nineteenth century city's social and environmental problems through the design of parks and parkways. He sought to improve the city's climate, to alleviate air and water pollution, to mitigate floods and to provide a naturalistic counter point to the city's modern infrastructure (Spirn, 1984, 243). In recent years some municipalities have started encouraging the design of stormwater ponds for multi-use like Olmsted's design for the Fens. The Denver metro area has a long history of combining stormwater with parks and open spaces. The Flood Control District of Denver has designed numerous parks to contain stormwater. 27 ED _ . Figure 3.3 Olmsted's 1894 plan for the Back Bay Fens and the Riverway (Tucker, 2001, 35) _yam, r 1. Figure View of Boston Riverway, 1920 (Tucker, 2001, 34) Examples Herbert Hosana Park, Colorado The Herbert Hosana Park is a school site being used as an off-line detention pond (Figure 3.5).Adjacent channels can carry flows up to the 25-year flood peak. The school grounds thus provide flood protection and are used as playfields including soccer fields and baseball fields, complete with press box and bleachers (DeGroot and Lloyd, 1992, 20). 28 Figure Herbert Hosana School Park, Colorado (Stahre and Urbonas, 1990, 34) Jefferson High School Athletic Fields, Colorado The athletic fields of the Jefferson High School in the city of Edgewater, Colorado, were built across a tributary to Sloans Lake with only an 18"pipe for drainage. As the upstream basin urbanized, flooding became a frequent occurrence. The solution was an off-line detention pond in the athletic fields. The excess flows of a 5- year peak are now detained on the athletic fields resulting in a 100-year flood protection downstream (DeGroot and Lloyd, 1992, 20). Wallace Park, Colorado Wallace Park is a 25-acre park designed by Wenk Associates, Denver. This park facilitates stormwater detention of 10-year or greater flood events thus providing flood protection and also park facilities to the adjoining offices and neighborhood (DeGroot and Lloyd, 1992, 20). The open areas are utilized for soccer and Frisbee games. The concrete low flow channel, which cuts through the center of the park, is combined with a walking path. The foot deep stream and the drop-structure "plazas" that punctuate the flow in three places, form play areas for children. These sandstone-colored plazas are studded with the "dragon's teeth", used by hydrologists in baffle-chute drop structures 29 e r-� ri- 6 Ft 4' S Fi rgu e 3.6 Wallace Park, Colorado (Strutin, 1991, 87) to slow down water (Fig 3.6). These form elements of children's play and due to its sculptural quality it also draws park visitors to the water's edge, where it swirls around the baffles. The adjoining offices also utilize it during lunch hours (Strutin, 1991, 87). The Wallace Park has become a valuable part of the community due to its multi-purpose amenities. Olympic Park, Colorado The Olympic Park in Aurora, Colorado, also designed by Wenk Associates, includes softball and soccer fields along with other park amenities.A three-quarter acre all-season wet detention pond holds runoff from the parking lot and surrounding area (Figure 3.7). The pond holds a maximum depth of three feet water; the excess travels through a system of perforated pipes and recharges the ground water. The pond is accessible by concrete steps. Children use the wading pond for recreation (MacElroy and Winterbottom, 2000, 102). The fountains, which aerate the water, also form a visual element and enliven the space. 30 j Fi rgu e 3.7 Detention pond in Olympic Park,Aurora, Colorado (McElroy and Winterbottom, 2000, 54) Other examples LeBreton Park, Canada The LeBreton Park is an inner-city Park within a housing development in Ottawa, Canada (Figure 3.8). It has a hard surfaced detention area to hold a 2-year flood peak. This detention area provides an ephemeral pond for play and recreation that is linked to the hydrological cycle (Figure 3.9). Roof water from adjacent housing and overland flow within the park is conveyed by a series of drainage channels into the pond. The pond fills up to a depth of 18 inches. The hard surfaced bottom is designed to permit many different activities. During winter it becomes an ice skating rink. During summer, after rain, the activity focuses on water play. When the water dries out, the area is taken over by roller skaters and skateboarders. Thus the children's activities respond to the changing environment. By accommodating such multiple uses of the detention area, children are brought close to the cycles of rain and sunshine (Hough, 1994, 92). 31 Weuin4ton Slreet 0� 1 1 ReFo soar on -� Fw C I \' Rola+aste[lon." —.- Children_$--'i 6 I Green i Play li -Steps PrInIfP9 Street ryry nnI ' Pldy p i Figure 3.8 LeBreton Park and surrounding residential area (Hough, 1994, 91) A 1 w Fiore e 3.9 Seasonal changes in children's play at the LeBreton Park (Hough, 1994, 93) 32 r 4.. Figure 3.10 Playfield in Sunset Meadow Park,Arlington, being used as a detention facility (Cappulli, 1984, 48) Arlington Heights, Chicago Arlington Heights, located to the northwest of Chicago, is an example of a community that works with the local government to develop stormwater facilities that serve dual purposes. Developers in Arlington Heights were required to provide on-site stormwater detention. They often turned these detention basins over to the community, which made agreements with the park district to maintain these areas as park or open space. But in the past these areas did not receive any design directions from the park district and often turned into a wasted space and a maintenance problem. Now the park district has an agreement with the community that they will only take over and maintain stormwater detention facilities that have a recreational use. Since then several recreational facilities like golf courses, ball diamonds, tennis courts, ice skating rinks, sledding hills and nature areas have been incorporated into detention ponds (Figure 3.10). In addition to providing flood control and aesthetic enhancement, the Arlington Lakes Golf Course uses its detention lakes for irrigation purposes. The facility also 33 provides year round use by offering the course as a cross country ski trail in the winter (Capulli and Jacobson, 1984, 49) Yauger Park, Washington The Yauger Park, located in Olympia, Washington is a 40-acre park and regional stormwater detention facility. It provides stormwater control as well as varied active and passive recreational opportunities. The park has three baseball fields, a playground, horseshoe pits, picnic tables, picnic shelter, one-mile jogging trail and a community garden. The park is designed to detain a 100-year storm event. Two settling ponds, the south parking lot and sports fields serve as stormwater detention areas. The park protects a commercial area downstream from flooding. Some of the playfields are built higher than the overflow structure hence they are rarely flooded (Weber, 1991, 61-62). Conclusion The examples above indicate that different kinds of recreational amenities can be incorporated in a stormwater detention facility and when these detention facilities are incorporated in parks and open spaces, they conserve space in urban areas while becoming community assets. Even the components of a detention facility can be designed as elements of play and to be visually attractive. Depending on the desired use of the facility, it can be natural or hard surfaced and have a hard edge or planted edge. Planning considerations for multi-use stormwater detention facilities There are several issues to be considered when planning for a multi-use stormwater detention facility, to make the facility acceptable by people. The primary considerations are regarding recreation, aesthetics, maintenance, safety, water quality and wildlife habitat. Care has to be taken to see that the recreational function does not 34 Figure 3.11 Detention pond in the backdrop of children's play area, Denver (Urban Drainage Criteria Manual, 2001, PL-22) interfere with the hydrological function and vice versa. Multi-use would also involve interdisciplinary planning. It would require planners, designers, ecologists and managers of the city to work together on stormwater problems. Recreation As seen in the previous section, stormwater ponds can be designed for active and passive recreation like playfields, game courts, golf course, ice skating rink, skate boarding, nature trailing and picnicking. For many non-water oriented recreation activities, such as golf and children's play areas, water forms "an important backdrop" (Tourbier and Westmacott, 1992, 2; Jones, 1990, 53) (Figure 3.11). Urban residents highly value access to water and an opportunity to be close to nature. Docks, piers, decks and boardwalks that provide access and give people the opportunity to touch water are important design features that should not be ignored. Using detention basins for recreation has both positive and negative aspects. The disadvantage is that the turf requires more care in high use areas compared to play areas 35 without detention facility. Poor drainage and excessive sedimentation can damage the turf. Hence turf should be of a species of grass, which can withstand inundation. Overseeding needs to be done frequently. Ball fields are more difficult to maintain in detention basins because they need a smooth and even turf(Cappulli and Jacobson, 1984, 70). The recreation facilities should not be placed near the bottom of the detention pond as it might become subjected to frequent flooding. Hard-surfaced game courts and playgrounds incorporated into detention basins may require greater maintenance due to the occasional silt deposition (Weber, 1991, 21) The detention ponds should be available for recreational activities as quickly as possible, following their use for runoff detention. Hence it is desirable to install a low flow channel to facilitate drainage. Bottom slopes should assure rapid drainage but should be carefully planned to minimize the likelihood of injury to sports participants (Jonathan Jones and Earl Jones, 1982, 325). Drainage of the pond bottom between storms has to occur efficiently if it is going to be used for recreation. To achieve this, the bottom has to be cross-sloped at no less than 2% towards the low flow channel (Stahre and Urbonas, 1990, 39) In case of dry detention basins, which are used as playgrounds between storm events, there is concern about the possible buildup of metals and other substances on to the dirt comprising the floor of the basin, and its effect on children playing in the material and inhaling the dust (Cobb, 1982, 19). For this purpose the soil should be monitored for levels of toxins and harmful metals like lead. It usually takes a very long period for the soil to reach any objectionable level of contamination. The sources of toxic contaminants upstream can be inventoried prior to building the facility and necessary action can be taken. 36 Figure 3.12 Detention pond near a Housing Complex, Colorado (Urban Drainage Criteria Manual, 2001, DP- 11) Aesthetics Aesthetics plays a major role in the public acceptance or rejection of a detention facility. For a detention pond to be an integral part of the community, it needs to blend into the landscape and into the community. Detention facilities can take a park-like appearance and actually enhance the aesthetics of an area (Debo, 1982, 334) (Figure 3.12). Wet ponds can be aesthetically pleasing and increase property values due to the waterfront effect. However there are differences in regional taste among people. For example, people in some areas enjoy a natural look with cattails and other aquatic life growing at the edge of the pond while others prefer a manicured lawn appearance around the pond. Dry ponds, on the other hand, may be perceived as unattractive by the public unless they are maintained as a lawn. Wet ponds can be unattractive if the pond regularly develops heavy algae growths and weeds (Cobb, 19, 1982). Excessive algae can cause odor and aesthetic problems. Lowering the impounded water surface for a time, then re-establishing it can sometimes accomplish effective algae and weed control (Jonathan Jones and Earl Jones, 1982, 327). Dry ponds do not have algae problems since water is drained frequently in- 37 between storms (Stahre and Urbonas, 1990, 52). In wet ponds, aeration and introduction of algae-eating fish can reduce the growth of algae. Fences, though used extensively for safety purposes, are considered unattractive. The use of natural landforms, meandering channels, water fountains, irregular configuration, gentle side slopes, mosquito control, planting of native trees and shrubs, concealment of inlets and outlets and other landscaping features can transform a detention facility into an attractive amenity for the neighborhood (Stahre and Urbonas, 1990, 32) (Urbonas, Carlson and Tucker, 1993, 17). Maintenance Maintenance of detention facilities is necessary for their hydrological functioning and acceptability by the community (Weber, 1991, 23). Easy and rapid access for maintenance equipment is essential to remove debris and sediment (Jonathan Jones and Earl Jones, 1982, 327). A maintenance access of width 12 feet is recommended to reach the key maintenance areas like inlet and outlet structures (Urban Stormwater Drainage Criteria Manual, 2001, MD-52) Sediment removal is one of the most expensive maintenance activities for detention ponds. When the suspended solids load is high, the ponds will have to be cleaned more often. Special considerations are necessary if the sediment contains elevated concentrations of metals and organics (Jones, 1990, 52). Limitation of sediment removal, hauling and disposal costs require acquisition and preparation of a nearby sediment disposal site when the detention pond is conceived and constructed (Jonathan and Earl D. Jones, 1982, 328) Other maintenance activities involve mowing, weed control, trash removal, algae control and mosquito control. Seeding the wetland with mosquito fish (Gambusia affinis) and dragonfly larvae, in addition to aeration, can control mosquitoes (Campbell 38 and Ogden, 1999, 121). Ponds should not be designed with steep slopes as they pose a difficulty in mowing. Generally, construction, operation and maintenance costs will be less for one large pond than for a series of smaller ponds (Jonathan and Earl Jones, 1982, 324). Sa&jy Human safety is another concern in the design of detention basins. The outlet of the basin is essentially a constricted culvert or a narrow pipe. The large volume of water exerts a lot of pressure on these narrow outlets leading to faster flow. According to Ferguson, conveyance should be as open and free flowing as possible. It should be slow, shallow and free of constrictions. Broad open weirs are much safer than narrow outlets. The basins are usually designed with steep slopes and located out of sight. This makes them more hazardous. The basin should be open and visible and accessible so that people can appreciate any hazard, take the necessary precaution, monitor others and provide rescue when needed (Ferguson, 1998, 26). Proper landscaping is a fundamental element in safety design. Fencing of detention ponds should be discouraged wherever possible. Fences are expensive to install and maintain, tend to be unsightly, produce "edges", which increase grounds maintenance needs, exists as a challenge to some of those they are intended to protect, and they impede emergency access in the unlikely event it becomes necessary (Jonathan Jones and Earl Jones, 1982, 325).Although safety should remain a concern, a properly designed detention pond should not be more hazardous than an urban lake, a playground, a hiking trail, or any other recreational or park facility in a city. It is definitely a safer facility than a city street, yet no one fences off the streets (Stahre and Urbonas, 1990, 36). 39 Figure 3.13 Hydraulic stucture blended into the landscape, Colorado (Urban Drainage Criteria Manual, 2001, HS-7) Hydraulic structures The planning, design, construction and maintenance of hydraulic structures must include considerations of aesthetics, safety and effects on the environment. Structures such as channels, inlet, outlet, overflow, grade controls, energy dissipators, maintenance roads and others can blend in with the park environment (Figure 3.13). The combination of diversity of forms, lines, colors and textures creates visual experience. Material selection and placement of vegetation can provide visual character and create interesting spaces in and around hydraulic structures. The use of planting that reduces erosion and dissipates residual energy are fundamental to good aesthetics and environmental quality as well as hydraulic function. In highly developed streamside areas, concrete plazas and edge treatment can be combined to increase channel efficiencies while providing access to waterway area. Natural materials like rock and vegetation can be used for bank stability while providing interesting spatial character and diversity. Some hydraulic and drainage features offer an invitation to play and hence should be made structurally safe and attractive (Urban Stormwater Drainage Criteria Manual, 2001, HS-107). 40 Water duality Urban detention ponds play an important role in stormwater quality management because they trap substantial quantities of pollutants. The pond should provide an average residence time of 24 hours for water quality. This will also eliminate mosquito problems since mosquitoes generally require 48 hours to breed and hatch. In a study conducted in New Jersey, it was found that the detention basins trap 60 to 70 percent of lead, total suspended solids and hydrocarbons during a detention time of 32 hours. Even during an 8-hour detention time, 30 to 40 percent of the pollutants are precipitated. A series of ponds can be more effective in removing about 80 percent of the pollutant (Jonathan Jones and Earl Jones, 1982, 321). Regular monitoring of water and sediment from the detention ponds should be done to ensure that they meet safety standards (Weber, 1991, 24) Wildlife habitat There is an opportunity to enhance wildlife in urban areas by creating wetlands as a by-product of stormwater management. Research initiated by the National Institute for Urban Wildlife (NNW) in 1982 found that typical grass detention basins were of little use to wildlife. Permanent shallow water impoundments with a variety of aquatic plants, gentle slopes and less open water provided good wildlife habitat (Campbell and Ogden, 1999, 196). A native vegetation edge will encourage wildlife to use the area and is also more consistent with enhanced pollutant removal (Jones, 1990, 53). Creation of islands, bays and particular aquatic plantings like pondweeds, wild rice, wild celery and duckweed that provide maximum food and cover, help in assisting wildlife habitat. The addition of nesting and roosting boxes along with feeding stations, floating platforms, bird houses, shelters for squirrels, cover for chipmunks and other wildlife can increase the attractiveness and functioning of wildlife habitats (Campbell and Ogden, 1999, 200- 41 201). Maintaining an unmowed buffer of at least 25 feet can provide a good terrestrial and aquatic habitat. Also varying the pond depth, with at least 25 percent area at less than 2 feet depth can diversify the habitat (Schueler, 1987). 42 CHAPTER FOUR CASE STUDIES This chapter looks closely at three case studies; Mill Creek Park in King County, Washington, Fishtrap Creek Nature Park in British Columbia and Skyline Park in Denver, Colorado.Among the facilities available for discussions, these three were specifically chosen due the difference in their location, setting, character and design approach. Mill Creek Park was designed by an artist and has a sculptural quality; Fishtrap Creek Nature Park was designed by an interdisciplinary team and has a very natural appeal whereas the Skyline Park is a hard-surface urban plaza in downtown Denver and is a part of an urban renewal scheme. CASE STUDY 1: MILL CREEK PARK The city of Kent is located in the south of the Seattle metropolitan region. Development of land in Kent, along Mill Creek had resulted in excessive flows of water during periods of heavy rain and the city needed a way of containing it and allowing it to recede slowly through the town (Beardsley, 1998, 94). In the late 1970's, the City's Public Works Department decided to fund and build a large regional detention pond along Mill Creek in response to the increasing volume of runoff generated in the 1500- acre watershed. Meanwhile, the King County Arts Commission had decided to fund an earthwork project. The Mill Creek Park site was selected for this project and it was decided to design a large multi-use stormwater detention facility. Herbert Bayer, the artist selected for the project, designed a park containing a group of earth forms (Figure 43 r f Figure 4.1 Mill Creek Park, King County, Washington (Matilsky, 1992, 46) 4.1). The earth forms are inundated during times of flood and provide an inviting 2.5 acre passive recreation park during dry periods (Beardsley, 1998, 94). The park is very successful in detaining stormwater and protecting downstream areas from flooding. The settling ponds effectively trap sediments thereby improving the water quality. The facility performed very well when tested by the severe 100-year storm on January 9, 1990. Without it flooding downstream would have been worse (Weber, 1991, 41). The total project cost came to $572,000. Out of this, 450,000 was provided by the City Engineering Department to pay for the detention basin and the rest of the money came from a wide variety of sources, including the Kent's Park Department and Arts Commission, the King County Arts Commission, the Washington State Arts Commission, the National Endowment for the Arts, a Housing and Community Development Block Grant and over 150 donations of varying amounts from individuals and corporations (Beardsley, 1998, 97). 44 Figure 4.2 Ring pond filled with water, Mill Creek Park, King County, Washington (Beardsley, 1998, 93) Description The Earthworks Park occupies 2-1/2 acres at the foot of the Mill Creek Canyon. It is designed for a 100-year storm event. The design consists of two steep sided irregular detention basins broken by berms and mounds. The major features of the design are two mounds, a cone that supports a bridge over Mill Creek, a shallow ring pond surrounding a ring mound and inner pond (Figure 4.2), and a ring mound sliced into two by the creek and supported by retaining walls. Turf is the main ground cover for all the features and the floor of the detention basin (Weber, 91, 36). The creek is first directed into a settling pond to remove sediment and debris. A controlled amount of stream water is diverted into a channel as part of the earthwork design, while the natural main channel remains to one side. The diverted channel meanders through the site and is lined with stone to prevent erosion. As it enters the park, it comes first to a mounded ring, 100' in diameter and 5' high, which breaks with the channel's passage. The channel then passes under a conical mound and another earthen ring. This ring seems to be suspended in a circular pool of water, 85' in diameter. This ring contains water part of the year and drains at other times to reveal the 45 Figure 4.3 Oval mound with a bridge, Mill Creek Park, King County, Washington (Bourdon, 1995, 227) full contours of the grass ring. Then comes the high berm topped with another cone. Below it is a final oval mound (Beardsley, 1998, 94) (Figure 4.3). Two sets of stairs with a viewing platform and a viewing tower are incorporated with the overflow structure. Benches and picnic tables are placed along an asphalt path, which meanders through the site. An amphitheater and a concert stage are located upstream of the earthworks by the settling pond (Weber, 1991, 37). Recreational amenities Bayer's Mill Creek earth forms are the focal point of the one hundred acre park. The park serves as a gathering place for community. The grass covered mounds, berms and level areas create a variety of spaces for people to stroll through and play on. Children enjoy climbing on top of the berms and rolling down the hill. The benches, picnic tables and viewing platforms provide opportunities for resting, picnicking and viewing (Figure 4.4). The settling pond, which provides habitat for salmon, offers nature watching and fishing opportunities. The ring pond and stream channel are aesthetically pleasing, especially when filled with water (Weber, 1991, 45). 46 4 Figure 4.4 Meandering asphalt path with picnic tablesMill Creek Park, King County, Washington (Beardsley, 1989, 48) Dances, concerts, weddings and a variety of other activities are scheduled every weekend (Figure 4.5). The park's landscape provides a beautiful backdrop for recreation activities. The `Canterbury Faire' is held every year in the park (Weber, 1991, 46). The park is closed during heavy rain and during maintenance. The maintenance requires 1 F Fi rgu e 4.5 Mill Creek Park during an event, King County, Washington (Beardsley, 1998, 93) 47 only a few days. Heavy rain events are rare and the facility dries very quickly after such event. Since there is only 5 inches of rainfall during the active recreation months - May through September, the facility is available during these months (Weber, 1991, 46, 47). Maintenance and other issues The park is well maintained by the Parks Department and Public Works Department of the city of Kent. The maintenance involves trash removal, regular mowing and annual dredging. Some features of the design pose a maintenance problem. The design does not accommodate access for heavy vehicles to the creek, ring pond and outflow. The paths are too narrow and steep in some places for vehicular access. Due to this, the silt has to be hand shoveled (Weber, 1991, 46, 47). The turf has withstood inundations well; perhaps due to the nutrients from the silt play a role in maintaining a healthy turf. But the steep slopes of the berms, mounds and ring pond pose a difficulty in mowing, resulting in an uneven appearance. The ring pond also develops algae on account of poor water circulation (Weber, 1991, 50). So far there have been no accidents or safety problems in the park.Also there does not seem to be a problem regarding the toxicity from the sediment. Conclusion Bayer's design for Mill Creek Park controls stormwater runoff into Mill Creek Canyon and is successful as both an artwork and a community gathering place. The park is a peaceful place where the sight and sound of water contributes a soothing place (Matilsky, 1992, 47). The city is proud of the project, calling it `a landmark in park design and a revolutionary concept in solving the problem of surface runoff (Beardsley, 1998, 97). 48 CASE STUDY 2: FISHTRAP CREEK NATURE PARK Figure 4.6 Aerial view of Fishtrap Creek Park,Abbotsford, British Columbia (www.dayton-knight.com) The Fishtrap Creek Nature Park in Abbotsford, British Columbia is a 57 acre park surrounded by suburban development in a small city in Fraser Valley (Figure4.6). The town of Abbotsford is located about 20 miles east of Vancouver in the district of Matsqui. Due to rapid development in the past thirty years and a heavy annual rainfall of 60 inches, the town faced increased flooding of farmlands. As a solution to this problem the municipality proposed two detention ponds in the Fishtrap Creek, which drains 7,526 acres of upland developed land and lowland farms as it flows south across the Canada-U.S border and joins the Nooksack River in Washington (Mooney, 2001, 66). The original purpose of the project was expanded by the landscape architects to include a variety of ecological and recreational objectives (Berris, 2000). The municipality acquired 57 acres of unused, overgrown farmland and woodland in the upper watersheds of the creek for the project. 49 7 - r Figure 4.7 Plan of Fishtrap Creek Park,Abbotsford, British Columbia (www.cbainc.bc.ca/s ervices/parksite.html) Description The existing creek was relocated to include meandering and a wider cross section (Figure 4.7). During peak flows, water overflows from the stream channel filling the adjacent created wetlands. Floodwater from the wetland is released downstream over a period of time through a control structure. The wetlands provide a detention area of 10 acre-feet accommodating a floodwater rise of 5 feet. The wetland is designed to capture 60 percent of the suspended solids from a one-hour duration storm of a 10-year storm event.A sediment pond between the northern and southern areas of the park removes further sediment from the runoff. Year round flow of the creek is maintained by infiltration of water (Mooney, 2001, 66). The detention ponds and the walkway around it have a naturalistic form with side slopes of 1:3 or 1:5 and are planted with native dogwood and willow shrubs. The floor of the wetland is planted with cattails (Typha latifolia) due to its biofiltration property, ability to colonize quickly and to withstand water fluctuations.A buffer of mature forest is retained along the steep southern boundary of the site (Mooney, 2001, 69). 50 Ami ' RLIL . Figure e 4.8 Entry Pier, Fishtrap Creek Park,Abbotsford, British Columbia (www.cbainc.bc.ca/services/parksite.html) Recreation amenities The Fishtrap Creek is extensively used by neighboring residents and people throughout the area. The park provides better shading, viewing and habitat possibilities, public recreation and education through ecological and cultural signage. The recreational uses are supported by a two-lane loop trail and six structures set within the f� � o Figure 4.9 Picnic Shelter, Fishtrap Creek Park,Abbotsford, British Columbia (www.cbainc.bc.ca/services/parksite.html) 51 park. These six structures, an entry pier (Figure 4.8), picnic shelter (Figure 4.9), reading shelter, pedestrian bridge, wetland boardwalk and a railway deck, support viewing, access and interpretation. The structures are made of massive timber posts that are reminiscent of the historical agricultural buildings of the region. The railway deck is located at a high point on the site and serves as an overlook point. Park activities include walking, bird watching and picnicking.Active recreation includes jogging, roller blading, cycling and softball (Mooney, 2001, 69). Wildlife habitat The site is heterogeneous and includes meadow, old-field habitats, mixed woodlands, and riparian and wetland habitats. The park is home to beavers, muskrats, turtles and a wide variety of birds like owls, migratory waterfowls and the blue and green herons, which annually visit the park (Mooney, 2001, 69). The shoreline of the detention ponds provides good wildlife habitat because of the gentle slopes and a variety of edge effect. The peninsulas and islands, which are inaccessible to humans provide very good nesting habitats (Berris, 2000). Although cattail was required due to large water fluctuations, the predominance of a single species reduces the habitat value. Also to achieve a large stormwater storage capacity, the woodland habitat was excavated and replaced with a wetland and riparian habitat thereby increasing riparian species and decreasing forest species (Mooney, 2001, 125). Maintenance Maintenance of most of the areas in the park is kept to a minimum, allowing it to undergo natural succession. Only the walking path is mowed and the rest of the areas are allowed to grow into a grassy meadow. Invasive species are removed manually (Mooney, 2001, 125). 52 Conclusion Both the users and the district engineering and park staff consider the park highly successful. The flood detention system has achieved its goal of mitigating peak flows and maintaining water quality while sustaining base flows. The project was headed by a multi-disciplinary team that included water resources and civil engineers, fisheries and wildlife biologists, soils and wetland vegetation consultants and landscape architects, including Catherine Berris. Both the passive and active recreation in the park is compatible with the wildlife habitat and flood control. In fact, the detention system provides the physical and visual setting for these activities (Mooney, 2001, 66, 123- 125). CASE STUDY 3: SKYLINE PARK, DENVER, COLORADO r: Figure 4.10 Skyline Park, Denver, Colorado (www.downtowndenver.com) 53 �L Figure 4.11 Skyline Park, Denver, Colorado (Greenberg consultants, 2001, 8) (www.downtowndenver.com) The Skyline Park in downtown Denver, Colorado is a major public open space (Figure 4.10). The park is a part of the on-site stormwater detention scheme that was adopted for the 80-acre downtown Denver business area of the Skyline Urban Renewal Project. The scheme called for storage of 3 inches of rainfall on all rooftops, in parking areas and pedestrian plazas (Wright, 1982, 297). Description The park, designed by Lawrence Halprin, is a three-block long detention basin with a width of 100 ft and an approximate area of 3.2 acres (Figure 4.11). The park comprises of a set of depressed walkways, raised planters with shade trees and a a Figure 4.12 Skyline Park, Denver, Colorado (Mooney, 2001, 66) 54 sculpted fountain in each of the three blocks. It also has a series of steps and levels, and is paved with concrete and brick. It is at a lower grade than the adjoining area and is surrounded by grass and concrete berms (Figure 4.12). The park is designed for a l0year and 100year flood event and detains water from rooftops and surrounding paved surfaces thereby reducing the storm flow rates to the available capacity of the downstream sewers. The park has flooded several times after its construction and functions very well. Since it receives runoff from paved surfaces, there are no sediment problems (Kenneth Wright, Personal communication). Recreation The park is used by people for strolling, eating lunch or just relaxing in the sun. Children use the park for skateboarding (Stahre and Urbonas, 1990, 33-34). Even when the plaza is filled with water, the upper levels provide seating and access across the plaza (Weber, 1991, 19). Revitalization of the Park The changing context, in particular, the fact that Skyline Park is literally bisected by the 16th Street Mall, which did not exist at the time of its creation and the fact that the Park has begun to experience some difficulties, including physical deterioration, set the stage for a fundamental reconsideration of its role and form (Greenberg, 2001, 8). Two ideas that strongly emerged in the revitalization project were the notion of the `piazza' at the junction with the 16th Street Mall - the hard surface; multipurpose ever-changing city space and the more pastoral soft and vegetated `gardenesque'park. Some modifications were also suggested which would open up the park visually, improve the relationship between Skyline Park, the immediately adjacent buildings and the adjoining streets. 55 The presence of water has been identified as a permanent element in the proposed design, as in the present design by Halprin. Water would link and unify all the three blocks of the Park and would animate the space throughout the year in its various states of ice, liquid and vapor. Although the new design calls for a number of changes, it will still retain the stormwater detention function. The new vision for the park will allow for the necessary on-site stormwater detention of approximately 5000cu.ft of water per block (Greenberg, 2001, 47). 56 CHAPTER FIVE DESIGN APPLICATION Design intent This chapter presents an additional design proposal for part of the Southeast Community Park in Athens, Georgia. The site has three detention ponds, which collect the runoff generated on site and from other uphill areas. The excess stormwater is directed to a creek that runs through the site. The ponds are a purely technical solution to the urban runoff problem and do not, in any way, contribute to recreational or aesthetic experience. They are located along the edge of the park and are hidden from the people visiting the park. The design intent of this thesis is to facilitate multiple-uses of these detention facilities by re-shaping the ponds into a more naturalistic form to provide recreational and wildlife benefits. The design also tries to integrate them into the park, making them more accessible. The aim is to make the natural process of stormwater visible and understandable to people through sight and sound and thus establish a connection between the urban environment and natural processes. The Site The site is located at the corner of Lexington and Whit Davis Road (Figure 5.1). It is an undeveloped tract of land measuring 146.39 acres. A creek runs diagonally northwest to southeast through the central portion of the site and divides the site into northern and southern parts. It is surrounded by undisturbed oak-hickory forest vegetation covering an area of about 51 acres.A spring located in the northwestern part of this creek provides a continuous source of water. The water drains into Shoal Creek 57 Athens - Clarke County '1 :row �' f.�•.+ Rn 1 ,.� -- I IN 141E Ir ATHEH IR -.P IR KEY ,( � Location of the Parkin Southeast i section of Clarke County Y Figure 5.1 Location of Southeast Clarke County Community Park in Athens- Clarke County (Courtesy - Robby Bryant, Robert and Company, 2002) 58 ._ it T-k. Ch h 7F5 IT o —al o� . A� NI Lull- 5 I ° � I is •I !rte— � 11 • •6T 1 Sir,p 71Y3 Y SHOAL CREE Figure 5.2 USGS map of east Athens,GA, 1998 Site boundary 59 11 4i .►s- Yw�XR+1F 1, r fix. Fi rgu e 5.3 Aerial view of the site before development, Site boundary January 1999 (www.terraserver.com) 60 located beyond the eastern boundary of the site (Figure 5.2). The northern part of the site is accessible by Lexington Road and the southern part is accessible by Whit Davis Road. The entire site slopes about 5 to 10% towards the creek. The slopes are steeper at the edge of the creek. Before development of the park in 2000-2002, more than 50 percent of the site had been cleared and maintained as a farmland (Figure 5.3). Single- family residences surround the site on the south and west.A commercial driving range borders the eastern edge of the site. The northern side is mostly undeveloped and consists of a mobile home park.A small tract of land measuring 9.743 acres, located on the northwest corner of the site, is designated as a future commercial area. At present the site contains two baseball fields, a football/soccer field, two tennis courts, a jogging/walking trail around the play fields, a concession building, a nature trail, and parking lots. All these facilities, except a parking lot, are located in the northern half of the site (Figure 5.4). The nature trail that runs through the wooded area is the only connection between the two parts of the site. Additional recreational facilities that may be constructed in the future, depending on the funds available, include two baseball fields, a football/soccer field, another concession building, a community building, some hard-surface courts and additional parking in the northern part and two baseball fields, three tennis courts and a community garden in the southern part (Robert and Company,1999). The vehicular access roads in both parts of the site, which are unconnected at present, would be connected in the future. There are three rectangular detention ponds located in the steeper northern part of the site, close to the creek. The ponds are designed for a 25year flood event. The first pond is located towards the north and is the largest of the three ponds. It occupies an area of 28,000sq.ft and has a depth of 1Oft. It receives runoff primarily from the parking lot and the area designated for future commercial. The second pond is the smallest, occupying an area of 8,790sq.ft and has a depth of 6ft. The third pond has an area of 61 3 p MER —� ,p .NA UR T L GREENWAY TRAI e Y 1 S r P r- 4 '^av NORTH e 0'so' 150' 350' Figure e 5.4 Existing plan of Southeast Community Park,Athens, GA� Existing vegetation Site Boundary (Courtesy - Robby Bryant, Robert and Company, 2002) �—� 62 11,600sq.ft and a depth of 6ft. The second and third ponds receive runoff from the play fields. The ponds are not hydraulically connected to each other and act as isolated stormwater detention systems. The ponds are provided with an outlet and an emergency spillway. Apart from the natural forest in the central portion on the site, the only vegetation in the park is street trees. The site exhibits high contrast between the turf- covered playfields and the natural forest vegetation. The following is a list of existing vegetation on site (Walter Cook, Personal communication). Existing vegetation on site A) Natural vegetation in the wooded section i) Canopy Trees Blackgum Nyssa sylvatica Eastern Red Cedar Juniperus virginiana Hickory Carya spp Loblolly Pine Pinus taeda Post Oak Quercus stellata Red Maple Acer rubrum Shortleaf Pine Pinus echinata Southern Red Oak Quercus falcata Sweetgum Liquidambar styracijlua Water Oak Quercus nigra White Oak Quercus alba Willow Oak Quercus phellos Winged Elm Ulmus alata Yellow Poplar Liriodendron tulipifera ii) Understory Black cherry Prunus serotina Blueberry Vaccinium spp Dogwood Cornus f orida Hawthorne Crataegus spp Japanese Honeysuckle Lonicera japonica Sparkleberry Vaccinium arboreum Sumac Rhus spp Tag Alder Alnus serrulata 63 iii) Vines Muscadine Vitus rotundifolia Poison ivy Toxicodendron radicans Smilax Greenbrier iv) Groundcover Ground cedar(clubmoss) Lycopodium complanatum v) Invasives Chinese privet Ligustrum sinense B) Vegetation planted on site i) Trees Crape myrtle Lagerstroemia indica Maidenhair tree Ginkgo biloba Plum cherry Prunus sp. Scarlet oak Quercus coccinea Willow oak Quercus phellos Existing;and potential wildlife on-site Raccoon, opossum, rabbit, squirrel, chipmunk, beaver, deer, wood duck, waterfowls, frog, toads, geese, owls, hawks, migratory song birds and other birds (Frank Henning and Walter Cook, Personal communication). Design Process Community suggestions The Athens-Clarke County held community input meetings for the purpose of selecting a suitable site and program for the park. The facilities recommended during these meetings included multi-purpose building, children's nursery, multi-purpose 64 athletic fields, baseball fields, softball fields, soccer fields, football fields, swimming pool, picnic shelters, playgrounds, recycling center, nature trail, tennis courts, parking, indoor soccer, batting cages, mountain bike trails, linkage to the greenway, barbeque shelter, walking trail, street hockey court, restrooms, a dog park, exercise trail, basketball court, open areas, canoeingiboating, fishing lake, amphitheatre and gardens. The recommendations were then ranked according to their priority. Following is the result of this prioritization (Robert and Company, 1997, 1, 3). 1) Athletic fields (including soccer, football, softball and baseball) 2) Passive nature areas (to include undisturbed land, nature trails and picnicking) 3) Paved paths (to include walking trail, greenway trail, exercise trail and bicycle trail) 4) Water features (to include naturally occurring features such as lakes and streams) 5) Tennis courts 6) Multi-purpose fields (to allow for unorganized free play, pick-up games and other games) 7) Multi-purpose buildings (to include classrooms and gymnasium) 8) Recycling center 9) Basketball courts 10) Playground (to serve all ages including pre-school and toddlers) 11) Picnic shelter (to serve large groups up to 500, moderate size up to 75, and small individual families) 12) Enclosed pool 13) Fitness center 14) Street hockey (to allow use for roller blade hockey) 65 15) Dog park 16) Swimming pool 17)Amphitheater— Outdoor terraces sited to blend with the existing topography. Seating capacity should be 500. National Recreation and Park Association Suggestions The National Recreation and Parks Association (NRPA) suggests that a community park should include an area of diverse environmental quality. It may include areas for intense recreational facilities, such as athletic complexes and swimming pools. However, the park should also include areas of natural quality for outdoor recreation, such as walking, viewing, sitting, and picnicking. The park should include a combination of the above facilities, depending upon site suitability and community needs (Robert and Company, 1997, 4). Initial Proposal Based on community recommendations and NRPA's suggestions, the Athens- Clarke County authorities and the landscape firm `Robert and Company' came up with an initial program and design for the Southeast Community Park (Figure 5.5). The design called for creation of a lake on the creek, at the center of the site. The lake would provide recreational activities like canoeing, fishing and bird watching, and would also detain the runoff from the site.A trail around the lake would serve for walking and jogging. Some spots along the trail would serve as picnicking and viewing areas. This trail and a vehicular road would connect the two parts of the site. The lake would be supplied with water from the spring situated in the wooded area. However the construction of the lake required clearing of most of the existing natural vegetation and also cutting off the flow of the spring downstream for thirty days so that the water 66 SOUTHEAST CLARKE COUNTY JW J7 COMMUNITY PARK MASTER PLAN Awl Y� .`.PAY Rd "-1-' � *!P �� •F py bb R?•'.�i.�.0— I,.�y ���,��_ �'. 2 Q v�y� � , LG�CE50!ME�.CRl. xGrue rww5 w-W. rxes sae:Pwro � 'wvur mac&--'W",----- - � Figure 5.5 Initial design proposal by Robert and Company, (Courtesy - Robby Bryant, Robert and Company, 2002) 67 would pond up in the lake. As soon as the desired level of water in the lake was reached, the water would then continue flowing downstream. The loss of considerable forest vegetation and interruption of the flow of the stream raised several environmental concerns, finally leading to the rejection of this initial proposal by the Athens-Clarke authorities (Robby Bryant, Personal communication). Present Site Condition The site is presently devoid of the lake feature and all the recreational facilities that the lake would have provided (Figure 5.6). Only a part of the nature trail exists on site (Figure 5.7). The site lacks any kind of water feature or areas for seating and viewing. The facilities like the community center and additional play fields might be incorporated in various phases in the future. Due to the rejection of the lake feature in the design, the three detention ponds that were constructed temporarily on site to take care of the runoff prior to construction of the lake are now a permanent feature of the site. These ponds have very steep slopes and are devoid of any aesthetics (Figure 5.8). They could be fenced off in the future to avoid people from getting close to them. The situation is another example of the conventional treatment and attitude towards stormwater detention ponds. Further proposal This thesis proposes a design that broadens the recreational and landscape program of the site by redesigning the detention ponds and the area around them. It tries to achieve the recreational goals of the initial proposal along with additional community needs, which had been rejected due to space constraints. The design deals only with on- site runoff and avoids changes to the existing recreational features on site. The design did not attempt to determine the runoff and detention volumes for the ponds since this 68 Fi rgu e 5.6 View of the site from the trail towards playfields (Photographed by author) Figure 5.7 View of the nature trail (Photographed by author) ill T t „ - r Figure 5.8 View of the large detention pond with play fields in the background (Photographed by author) 69 had been already determined. However care was taken not to reduce the existing storage volume of the detention ponds while re-shaping thereby maintaining their original detention function (Ferguson, 1998, 165). The design will mainly concentrate on the linear strip of land that measures about 17.32 acres with the detention ponds. Site assets The site is easily accessible and highly visible from the adjoining roads (Refer figure 5.4). The central portion of the site containing the creek and undisturbed forest vegetation forms a major asset to the site. It enhances the potential to provide wildlife habitat, nature trails and create viewing area. It also forms a beautiful backdrop for the site. Excess stormwater can continue to be directed to the creek, not requiring any connection to municipal drain. The overall slope towards the creek provides advantage in directing the stormwater to the creek. The site adjoins a trail on the western edge that is a part of the regional greenway masterplan. Hence a design, which provides wildlife habitat and various passive recreational opportunities, can be an attraction along this greenway corridor. Design constraints and considerations The main design constraint is the availability of space. Play fields and parking lots occupy most of the site hence there is little room to enlarge the detention ponds in order to incorporate shallow slopes while maintaining the same volume to detain stormwater. The wooded section of the site places a further constraint along the southern border. Because the site slopes towards the creek, there would be a need to build embankments to enlarge and re-shape the detention ponds. The slope is steep in some sections near the creek making it difficult to construct trails that would be consistent with ADA(Americans with Disabilities Act) access codes. Because the 70 detention ponds lie between an urban park setting and undisturbed natural vegetation, the design would need to respond to the character of both these settings. The design would also need to provide adequate handicapped access to the additional facilities that would be proposed. Proposal description The design celebrates stormwater and educates us to its fate in the urban environment. By incorporating various features like water channels, swales and fountains, the journey of stormwater is made more enjoyable and pleasurable (Figure 5.9). An 8ft wide two-way pedestrian trail paralleling the flow of stormwater provides access and view of stormwater as it makes its way from the high pond to the lower pond. The trail is constructed of porous concrete to absorb rain water. This also reduces maintenance and provides easy universal access. The detention ponds are re-shaped into naturalistic forms with slopes of 1:5 or 1:10 and planted with native vegetation and willow shrubs to absorb the pollutants and stabilize the banks. Boulders placed along some sections of the channels act as energy dissipators. An additional pond is proposed in the northwestern part of the site to treat the first flush of stormwater from the future commercial area (Figure 5.10). The pond is shaped and oriented to capture maximum possible runoff from the future commercial site above and is lined with native vegetation to absorb pollutants. Trash and sediment traps are located at the inlet and outlet of this pond to enhance the water quality. Excess water overflows from the pond through the outlet into a swale. It is joined by another swale that carries stormwater from the proposed parking lot. The water then pools up into a small pond. This helps in slowing down water and also facilitates infiltration. The water then flows over the concrete tiers of a proposed amphitheater. The tiers are depressed into the ground where water flows over them. These depressions act as flow FUTURE COMMERCIAL ' i' 71 AREA ! I S I ° _ f i etf ------------------ ,1'•�I V _---------- ----720 7� 1�1f1f -- ----- ------------ — ''1�• } J ` r ------------ f 1 ...• - - n n . 'VIN r " --�1 � ,� _ 2726 72 lA I l .� XATURETRAIL`'-= - - r '� �•�. _ _ 1 r i + �_ 4 --- _ r LVADO WLDFLOWER #� f T — ———— -------- -----------. IYEJ4QOp' —---- �- " gar. I ;-- BOARDWALK • r - r! �~� ��'�-`"-fi . �4,• �?`5, y n - - � t�t-, •�, try � I � -� j� L i �'r a 0 _ ,l am. •'i�.c'`,'. _f ELTEN _ - •A E _ it 0 I�JfI L Nd SPLUM F l •,.� ° VE Exit TRTIWM -Z NORTH Y J o so 00 200' SCALE Figure 5.9 Proposed design masterplan for part of Southeast Community Park,Athens, GA iz 8lL _ CL CD _. 1, .,�k LU cn tLi LU LLF CL M L v LLJ LU LU LL. LU UJ w � cc uj t 1 - "� ,.'-���'4I��� �: �.•i i'+ .ir' .� s `5 iTa9kRy F1 73 concrete tiers weir —7'deep channel in i.gyp. �� _ carinei s'agL -- Figure 5.11 Section through amphitheater and water channel 0' 5' 10' 20' SCALE sr lh 5 ..- 1 �YF S i `t wh - r [i�3f dU 1h ti." `�` a'i }: .hy_ ✓-V 5 1 }. .]A.,. .. T tl...' ••tt,'Y �...° - . -J f .-.JW-�Y� '"•W �L � T yR ' I MW I& W*e WE*r wAvrey' 'male tai _ ..�_. .w � - -- - Md B L 7 1 a am ampltiA ear stage s POW '- Figure 5.12 General section through amphitheater and large detention pond " 0' 10 ' SCALE 74 forms (Schwenk, 1976), pulsating the water further down the site (Figure 5.11). The flow of water through these sculptural forms acts as a visual feature and also helps in improving the water quality by aeration. The water channel then splits around the stage of the amphitheater and reconnects on the other side. Access to the stage is provided by stormwater grates placed over the channel at three points allowing the sight and sound of water in the channel while it passes below. The water then pools up again in a small pond before entering a large detention pond. The water channel leading from this small pond to the large pond is gradually broadened and made shallow. Stepping-stones placed in this portion of the channel break the flow of water into several irregular channels that eventually discharge into the large detention pond (Refer figure 5.10). These stepping- stones not only act as hydrological structures but also become a feature of children's play. A 12ft wide concrete platform on the northern edge of the large pond provides access for recreation and vehicular access for maintenance.A part of the detention pond is designed with a steep slope. The concrete platform near this steep part of the pond provides fishing opportunities and also acts as a viewing deck. It is secured with a wooden railing. A part of the railing is lowered to cater to handicap fishing access. The handrail has holes to anchor fishing rods.A pergola, benches and picnic tables are located along this edge of the pond to provide shade and serve as rest areas for anglers and pedestrians. The large pond is designed as a wet pond providing the benefits of a small lake. It is planted with wetland vegetation that improves water quality and enhances the appearance of the pond. The pond would contain native varieties of fish suited to the environmental conditions in the detention pond. The fish would attract raccoons and other wildlife.An island located in the center of the pond is inaccessible to humans and 75 serves as a good spot for wildlife. Wooden logs and large stones placed in and along the pond provide perching opportunities for birds and act as water level markers, displaying changes in the water level with passing storms. Clusters of bubblers are placed at three places in the pond. These small fountains aerate the water by throwing it to a height of about 2 to 3ft providing thermal mixing of the water and improving the oxygen content, which is necessary for the fish in the pond, enhancing water quality and inhibiting the growth and spread of mosquitoes. The advantage of these small bubblers in contrast to powerful jet fountains is that they prevent the loss of water by evaporation, which can be important for a pond with a small watershed. The water travels around the island and overflows through a spillway. By directing water around the island, it is made to travel a longer path, which helps in improving the water quality. But in case a very large amount of water enters the pond during an extraordinary storm, it short circuits this path and directly overflows through the spillway. Figure 5.12 shows the various activities taking place along the water channel and the large detention pond. The spillway is in the form of a set of roughly cut curvilinear granite steps having a rise of 6 inches each. The steps facilitate re-aeration of water as it leaves the pond, further enhancing the water quality, before it flows into the creek. The water cascades over these steps forming a visual feature. The flow of water from the spillway is routed to the existing outlet path but is converted into a more naturalistic path in contrast to the existing outlet of riprap. The outlet channel is broadened and is fitted with boulders and native vegetation to help slow down water as it flows over the steep slope. In dry seasons, this pond can be supplemented with municipal water supply or well water to keep the fish alive and to retain the appearance and recreational value of the site. The concrete platform along the edge of this wet pond connects to a pedestrian path, which leads to another detention pond. This pond is re-designed from present - -------------------------------------------- j --------------- . d�i'•r N r;., ,� �, �+• '� � of - JJ SHELTER.J, k w OPEN <; PLAZA -_,bridge 1 ; _ (maintenance access road) �. Pic table elk trail ; railing wa FOREST VEGETATION. . ' 6r g �`` ncrgiWannel weir' perrilat. - Nk d pimp Po stepping sto pebbles 77'4 'lid EXISTING FOREST A _. F ... 712 NORTH - 0' 25' 50' 100' f4. SCALE Figure 5.13 Detail plan of`Splash pond' and surrounding area 77 condition to serve as a "splash pond" for children (Figure 5.13). It provides interactive play opportunities with water. As this pond receives runoff from the turf-covered play fields, there is no concern about objectionable urban pollutants. The pond is divided into a shallow, ephemeral section and a deeper, perennial section. The shallow section has stepping stones to provide access for wading. Depending on the amount of water entering the pond, these stones may be partially or completely submerged in water. The maximum water depth permissible in this shallow section is only 16 inches (Figure 5.14). There is an 8 inch pebble layer beneath the water. The stepping-stones rise 8 inches above this pebble layer. The pond has a 6 inch concrete base and is surrounded by granite steps. The steps provide seating for children and parents while viewing and supervising their kids. The deeper section of the pond is 2ft deeper than the shallow section and is a permanent pool. It has a low stainless steel railing to demarcate it from the shallow portion and prevent any accidents. The railing also provides support to children while crossing the pond.A hand pump is located at the edge of this pond. Children can pump water from the pool and watch the flow of water through the channel. The shallow section of the pond drains completely after a storm exposing the stepping stones and pebbles. Picnic tables and benches are located near the pond to provide resting and viewing opportunities. The water flows out of this pond slowly through a weir located at the end of the pond. The water channel from this pond is curvilinear and is lined with concrete to allow access for play. It is fitted with low walls that serve as seating while playing in the channel. The channel is also fitted with weirs that can be opened and closed with shutters operated by hand. Excess water spills over the weirs. Small boulders placed along the channel act as energy dissipators helping to slow down water and provide visual feature, as water splashes over them. The channel gradually broadens and \\ - 78 CD t � CL CL M e \ . �. � r ; .. � �£ u> � . , . ..� � o ro 2 �\ m > \ G �\ _ 79 becomes more naturalistic. It is lined with vegetation and fitted with boulders. It finally drains into the large detention pond. A circular shelter and a circular open plaza measuring 40ft in diameter are located alongside this channel, near the existing parking lot, to provide rest and picnic opportunities along the trail while viewing water (Figure 5.15). The shelter is fitted with benches. These structures overlook the large detention pond and provide opportunities to view wildlife. They are surrounded by vegetation to conceal their presence and merge them with the natural setting. They are accessible by bridges connected to the pedestrian trail. A flight of steps from the parking lot to the trail provides direct access. The floor of these structures is made of granite tiles cut in circular patterns. The roof of the shelter is located at a height of 12ft and is made up of red cedar wood and supported by posts of the same material (Refer Figure 5.14). The trail further connects to another, more isolated pond. Benches are placed along this part of the trail. The pond is re-designed from present condition into a natural wetland (Refer figure 5.9).A 6ft wide secondary trail loops around the main trail providing wildlife viewing opportunities. A boardwalk from this secondary trail leads to a viewing deck, which is provided with benches. The main trail is then connected to the existing trail that runs around the playfields. The wetland area is a detention basin. It receives runoff from the play fields and stores it to facilitate infiltration. The wetland vegetation helps to remove sediments and facilitates infiltration of water. Excess water flows, flowing detention, through the spillway to the creek. This spillway is designed in a similar manner as the one for the large detention pond but without the re-aeration feature. A building proposed in the northwestern part of the site, covering an area of about 6900sq.ft, serves as a Nature Center (Refer figure 5.10). It would contain classrooms, auditorium and facilities for staff. The building facilities would provide 80 Jk jA I 33 4 7h i r • •T7 i 81 information about the hydrological function of the park and educate people about the wildlife and vegetation existing on site. It would provide opportunities for community gatherings, school field trips and special events. Vehicular access to the building is by the existing road on site.Additional parking with handicap facilities for the Nature Center is also provided on the eastern side of the building. The roof of the Nature Center building is arched towards the south and fitted with solar panels that provide energy to run the bubblers placed in the large detention pond. The existing nature trail that connects to the sidewalk on the main access road is re-designed into a smooth curve. This trail runs through the wooded section of the site and connects to the other side of the park.A pedestrian path proposed in front of the Nature Center and along the parking lot connects to the existing road, providing access to the Center from the road. This path is also connected to the curvilinear trail. Wooden bridge is provided at the point where the path and trail intersect the water channel. The road connecting the main road and the existing parking lot is re-aligned to provide vehicular access from the main road to the proposed parking lot for the Nature Center. A 12ft wide road continues further to provide access to the proposed maintenance building located in the northwestern part of the site. A swale around the Nature Center discharges water into the channels. The Nature Center overlooks the whole area of the paths, channel, amphitheater and the large detention pond. Being consistent with the expressed community needs, an outdoor informal amphitheater is planned as one of the facilities on site. The amphitheater takes a semi- circular form (Refer figure 5.10). Flights of steps on either side of the amphitheater provide access to the tiers and the stage. The tiers are extended on the northwestern side to merge with the topography of the site. The amphitheater would be used for small concerts, community gatherings and outdoor classes or just hanging around, viewing and other leisurely activities. The extended tiers provide opportunities for seating and 82 viewing even when the amphitheater is being used for a different purpose. A secondary trail on either side of the amphitheater connects it with the main trail. The space between the tiers would be maintained as turf. Proposed vegetation Trees and other vegetation are proposed to provide shade and to blur the contrast between the design area and the wooded section along the creek. The design proposes various zones of vegetation like turf, wildflower meadow, forest vegetation, riparian and wetland areas, exhibiting a heterogeneous character. This helps in diversifying wildlife and provides different recreational opportunities. The pedestrian trails cut through these varied vegetation zones providing people different experiences of nature. Trees proposed along some of the detention ponds help in preventing loss of water due to evaporation and reducing the temperature of the water, which increases its oxygen content. The vegetation also provides food, shelter, cover and nesting opportunities for wildlife. Bird houses, nesting and shelter boxes placed in appropriate vegetation zones and concealed from the pedestrian circulation areas will help in increasing the use of this area by wildlife. The trees were selected based on the existing trees in the wooded section. Bermuda grass is proposed in the amphitheater area. Centipede grass is selected along the trails as it requires low maintenance and is also drought tolerant. Some of the species selected for the meadow, like chickweed, provide food for birds. The wetland plants were selected based on their pollutant removal properties and ability to withstand frequent changes in water level. The design proposes bioengineering techniques for stabilizing the edges of the large detention pond. Vegetation proposed along the future commercial area, existing parking lot and wetland pond helps in reducing noise pollution and acts as a buffer. Following is a list of the proposed vegetation. 83 Proposed vegetation i) Turf areas Bermuda grass Cynodon dactylon Centipede grass Eremochloa ophiurides ii) Wildflower meadow Aster divaricatus Aster sp. Blazing star Liatris microcephala Blue-eyed Susan Rudbeckia sp. Broomsedge Andropogon virginicus Chickweed Stellaria sp. Cone flower Echinacea sp. Fringed loosestrife Lysimachia ciliata Goldenrod Solidago sp. Indian grass Sorghastrum nutans Joe Pye weed Eupatorium fistulosum Purpletop Tridens flav us Spitheara Bluestem Andropogon ternaries St. John's Wort Hypericum multilum Sunflower sp. Helianthus sp. Switch grass Panicum virgatum iii) Canopy Trees Blackgum Nyssa sylvatica Hickory Carya sp. Post Oak Quercus stellata Red maple Acer rubrum Southern Red Oak Quercus falcata Tulip Poplar Liriodendron tulipefera White Oak Quercus alba iv) Understory Buttonbush Cephelanthus occidentalis Silky dogwood Cornus amomum v) Bioengineering Alder Alnus sp. Black willow Salix nigra 84 vi) Wetland Arrow arum Peltandra virginica Arrowhead Sagittaria latifolia Bulrush Scirpus sp. Pickerel weed Pontederia cordata Soft rush Juncus effusus Spatter dock Nuphar luteum Swamp milkweed Asclepias incarnata Water lily Nymphaea sp. Maintenance Vehicular access to the detention pond for maintenance is provided from the existing parking lot. This access road connects to the pedestrian trail. The 8ft wide trail with 2ft grass shoulder on either side serves as the vehicular access paralleling the water channel. The maintenance of this section of the park, with the detention ponds, will be kept to a minimum. The detention ponds may require dredging at interval of years depending on the amount of sediment. The inlets, outlets and other hydraulic structures will require regular inspection and cleaning to prevent clogging from trash and sediments. The park, outside grass and meadow areas, would be allowed to undergo natural succession. The turf in the amphitheater area will require mowing every 2 to 3 weeks. The grass along the trail would not require frequent mowing as centipede grass is a slow growing grass and does not grow very tall. The vegetation along the detention ponds would require harvesting to control overgrowth. Other maintenance would involve clearing and litter removal, keeping the trail surface in good condition, removal of obstructions along pedestrian and vehicular routes, removal of dead vegetation and keeping the views unobstructed. 85 Additional recommendations The proposal recommends monitoring water quality of the facility by taking regular samples from the detention ponds. School groups and volunteers can take active part in this activity thereby increasing their understanding of water quality issues and solutions. The proposal goes beyond the design area limits and proposes the restoration of the creek. At present the creek is occupied by a lot of invasive species, privet being the most dominant. Due to the massive presence of these invasive species, there is absence of ground cover. Removal of the invasive species would help in the colonization of native species. It would have an added advantage of providing better views along the nature trail and benefit the wildlife. The spring, which at present is visible only at a few points along the trail, will also be visible and enhance the aesthetics of the site. The spring channel should be planted with ferns and other wetland species recommended in this thesis, which would help in stabilization of the channel and enhance its appearance. Public awareness and involvement Many ecological designs in the past have failed due to lack of awareness of their functions by the people using them. Hence this design recommends interpretive signage and information kiosks along the trail and other pedestrian areas that would make the visitors aware of the hydrological function of the park and its benefits. This would help in preserving the landscape and assist in its proper functioning. It would also help in respecting the presence of wildlife by humans, as the wildlife is intended to be an integral part of this part of the park.A program should be designed for the Nature Center that helps in getting the communities involved in the working of the park. School trips, visitor orientation, informative brochures and special weekly or monthly events related to the park can be organized to educate the people about the park. 86 Volunteer programs can be organized for the planting, cleaning and overall maintenance of the park to get people and surrounding neighborhoods involved in the working of the park. Only through public involvement can a park become an integral part of the community. Conclusion The design converts a currently wasted space into a recreational and educational amenity while providing detention facilities. The proposal takes advantage of the fact that the interface of land and water holds attraction for most people. The design brings together geometric and naturalistic forms creating a harmony in the landscape. By incorporating various kinds of water features and structures, the design caters to all age groups and varied interests. Some of the hydraulic structures also become a part of natural setting and provide recreational opportunities. The design exposes the flow of stormwater and brings people into contact with it, putting it back into the social consciousness of urban society. The debris and trash collected in the sediment pond will heighten awareness among people about their role in keeping the environment clean. The proposal attempts to serve not only human needs but also respects wildlife and vegetation, and tries to provide for their benefit. It returns cleansed water back into the system, completing the hydrological cycle. The design also enhances the regional greenway corridor. The overall project cost would be about $1,484,800. The proposal illustrates that detention facilities do not have to be sterile and ugly but can be attractive and form sustainable systems. The design attempts to change the perception of stormwater systems. It displays that stormwater can be transformed from a liability to an asset. It is a step toward increasing public awareness of stormwater. By recommending restoration of the creek, the proposal goes beyond its design area thereby taking care of the complete hydrological system. By recommending 87 natural succession and minimum maintenance, the proposal tries to increase people's respect for lightly maintained open spaces in contrast to the highly maintained park areas. Although the proposal demonstrates that such multi-use stormwater systems can be retrofitted, incorporating such ideas early into the design process has additional benefits. The design constraints will definitely be less and the project could be more economical. The present proposal being a retrofit faced several design constraints, space being one of the most important. Although the proposal tried to retain the existing topography, considerable re-grading would have to be done. But the benefits would certainly be worth it. Had the proposal been thought of in the beginning of the design process, it would have been more integrated with the rest of the park facilities. The design sets an example to be followed for future stormwater management projects illustrating that active and passive recreation, and wildlife habitats can be compatible with stormwater detention facilities. Such multi-use designs can make stormwater facilities acceptable and desirable in communities and thus encourage municipalities to change their approach to treating stormwater. Stormwater should be viewed as an opportunity to go beyond the basics of civil engineering, to involve landscape architecture and aesthetics, in creating sustainable landscapes.Architects and landscape architects should play an important role in designing, developing and marketing such multi-use and sustainable landscapes, which are the growing need of today's urban environment. All parks and open spaces should incorporate such hydrological systems forming a network and thus alleviate the landuse pressure. 88 SELECTED BIBLIOGRAPHY Water and Stormwater management Adams, Lowell W., Daniel L. Leedy and Thomas M. Franklin, "Wildlife Enhancement in Urban Stormwater Control", Proceedings of the Conference on Stormwater Detention Facilities: Planning, Design, Operation and Maintenance,American Society of Civil Engineers, New York, 1982: 384. Betsky,Aaron, "Take me to Water", Architecture and Water,Architectural Design Magazine, 1995: 8. Campbell, C. S., and Ogden, M. H., Constructed Wetlands in the Sustainable Landscape, New York: John Wiley and Sons, 1999. Capulli,Angelo J., and Susan L. B. Jacobson, "Water, Water, Everywhere", Parks and Recreation, volume 19, number 2, February 1984: 48-49, 69-70. Cobb, Ernest D., "Planning Considerations for Detention Basins", Proceedings of the Conference on Stormwater Detention Facilities: Planning, Design, Operation and Maintenance,American Society of Civil Engineers, New York, 1982: 16. Dapkus Kathleen, "Vegetation Alternatives for a Detention Basin with Severe Conditions", Unpublished MLA Thesis,Athens: University of Georgia, 1993. Debo Thomas N., "Detention Ordinances — Solving or Causing Problems?" Proceedings of the Conference on Stormwater Detention Facilities: Planning, Design, Operation and Maintenance,American Society of Civil Engineers, New York, 1982: 332. DeGroot, William G, and David W. Lloyd, "Detention in Parks and Open Spaces- Good, Bad and Ugly", Flood Hazard News, Urban Drainage and Flood control District, volume 22, number 1, December 1992: 19-21. Don, Henry, "America's Waterfronts are Looking Better", Water Spectrum, U.S Army Crops of Engineers, volume 12, number 4, Fall 1980: 43-46. Dreiseitl, Herbert, "Water is Universal", Waterscapes: Planning, Building and Designing with Water, Dreiseitl, Herbert, Dieter Grau and Karl H. C. Ludwig Eds. Basel, Berlin, Boston: Birkhauser, 2001. 89 Ferguson, Bruce K., " The Failure of Detention and the Future of Stormwater Design", Landscape Architecture, volume 81, number 12, December 1991: 76-79. Ferguson, Bruce K.,Introduction to Stormwater: Concept, Purpose, Design, New York: John Wiley and Sons, 1998. Gregg, Billy and William Wenk, "Stormwater Gardens (Convey, Capture and Reuse: Stormwater)",Landscape Journal Special Issue, 1998: 24-25. Jones, Jonathan E., "Multi-purpose Stormwater Detention Ponds", Public Works, New York, December 1990, volume 121, number 13: 52-53. Jones, Jonathan E., and Earl Jones, "Interfacing Considerations in Urban Detention Ponding",Proceedings of the Conference on Stormwater Detention Facilities: Planning, Design, Operation and Maintenance,American Society of Civil Engineers, New York, 1982: 317. Jones, Julian, "Water: Designing for Plenty and Purity",Architecture and Water, Architectural Design Magazine, 1995: 16. Litton, B. R., Tetlow, R. J., Sorensen, J., and Beatty, R.A., Water and Landscape:An aesthetic overview of the role of water in the landscape, New York: Water Information Center, Inc. Port Washington, 1974. MacElroy, William P., and Winterbottom, Daniel P., "Stormwater Ponds",Landscape Architecture, volume 90, number 4,April 2000: 48-54, 102-103. Magnarella, Christine Jo, "The Creation of Multifunctional Wetlands for Wastewater Treatment and Wildlife Habitat", Unpublished MLA Thesis,Athens: University of Georgia, 1997. Moore, Charles, "The Potential for Wonder",Architecture and Water,Architectural Design Magazine, 1995: 22. Northcutt, Greg, "When Sediment Control goes Underground",Erosion Control, July- August 2001. (http:forester.net/ec-0107—when.html) Russell, Zolna, "Rain Gardens", Landscape Architecture, volume 90, number 7, July 2000: 24. Schueler, T. R., Controlling Urban Runoff:A Practical Manual for Planning and Designing Urban BMPs, Washington D.C: Metropolitan Washington Council of Governments, 1987. 90 Stahre, Peter, and Ben Urbonas, Stormwater Detention for Drainage, Water Quality, and CSO Management, Englewood Cliffs, New Jersey: Prentice Hall, 1990. Strutin, Michele, "Two Parks that Quiet the Storm",Landscape Architecture, volume 81, number 10, October 1991: 84-87. Terry J. Logan, and Stephen M. Yaksich, "Lake Erie: A New Prognosis", Water Spectrum, U.S Army Corps of Engineers, volume 12, number 3, Summer 1990: 26-29. Tilton, Joseph L., "Helping Stormwater Keep its Place", Stormwater, volume 3, number 6, September/October 2002: 40-51. Tourbier, Toby J., and Richard Westmacott, Lakes and Ponds, The Urban Land Institute, Washington, D. C., 1992. Toy, Maggie, "Editorial",Architecture and Water,Architectural Design Magazine, St Martin's Press, 175 Fifth Avenue, New York, NY, 1995: 6. Tucker, Mathew, "Rants and Raves: Boston's Emerald Necklace", Land Forum, Issue 10, 2001: 34-37. Tunney, Kathleen W., "Stormwater Innovative Design: The Role of Landscape Architect", Stormwater, 2002. (http://www.forester.net/sw—O 10 1—innovative.html) Urban Stormwater Drainage Criteria Manual Volume I and 2, Denver, Colorado: Urban Drainage and Flood Control District, June 2001. Urbonas, Ben, Jay Carlson, Scott Tucker, "Detention in Parks and Open Spaces- Good, Bad and Ugly", Flood Hazard News, Urban Drainage and Flood control District, volume 23, number 1, December 1993: 1, 17. Wanielista, Martin P., and Yousef A. Yousef, Stormwater Management, New York: John Wiley and Sons, 1993. Weber, Mary M., "Incorporating Stormwater Detention into Parks with Multi-use Amenities: Two Case Studies", Unpublished Masters Thesis, University of Washington, 1991. Woodward Robert, "Water in the Landscape", Waterscapes: Planning, Building and Designing with Water, Dreiseitl, Herbert, Dieter Grau and Karl H. C. Ludwig Eds. Basel, Berlin, Boston: Birkhauser, 2001. 91 Wright, Kenneth R., "Stormwater Acceptance and Rejection Issues", Proceedings of the Conference on Stormwater Detention Facilities: Planning, Design, Operation and Maintenance,American Society of Civil Engineers, New York, 1982: 284. Land Art and Design Beardsley, John, Earthworks and Beyond: Contemporary Art in the Landscape, New York: Abbeville Press, 1998. Bourdon David,Designing the Earth: The Human Impulse to Shape Nature, New York: Henry N. Abrams, Inc., 1995. Calabria, Tamara G, "Representation of Stormwater Management in Design: Toward an Ecological Aesthetic", Unpublished Masters Thesis,Athens: University of Georgia, 1995. Healan, Ryan, "The Potential of Stormwater as Design Element", Unpublished Masters Thesis,Athens: University of Georgia, 2001. Kastner, Jeffery and Wallis, Brian Eds,Land and Environmental Art, Phaidon Press, 1998. Matilsky, Barbara C., Fragile Ecologies: Contemporary Artists'Interpretations and Solutions, New York: Rizzoli, 1992. Oakes, Baile, Ed., Sculpting with the Environment-A Natural Dialogue, New York: Van Nostrand Reinhold, 1995. Renneker, Marion L., "Go with the Flow", Unpublished Masters Thesis,Athens: University of Georgia, 2002. Ecology and Urban Planning Hough, Michael, Cities and Natural Process, New York: Routledge, 1994. McHarg, Ian L., Design with Nature, Garden City, New York: Double Day/Natural History Press, 1969. Nassauer, Joan Iverson, "Messy Ecosystems, Orderly Frames",Landscape Journal. Landscape Architecture, volume 14, number 2, Fall 1995: 161-170. 92 Schwenk, Theodore, Sensitive Choas, New York: Schocken Books, 1984. Spirn,Anne Whiston, The Granite Garden, New York: Basic Books, 1984. Thompson, W. J., and K. Sorvig, Sustainable Landscape Construction:A Guide to Green Building Outdoor, Washington, D. C.: Island Press, 2000. Recreational Planning Charles A. Flink, Kristine Olka and Robert M. Seams, Trails for the Twenty-First Century: Planning, Design, and Management Manual for Multi-Use Trails, Island Press, Washington, 2001. PLAE, Inc,A Design Guide: Universal Access to Outdoor Recreation, Berkeley, CA, 1993. Southeast Clarke County Community Park Robert and Company, "Site Identification and Evaluation, SPLOST IV Project No. 28, Southeast Clarke County Community Park",Athens-Clarke County, GA, February 1999. Robert and Company, "Hydrology Study for the Design of Southeast Clarke County Community Park",Athens-Clarke County, GA, 2000. Robert and Company, and Planners for Environmental Quality, "Southeast Clarke County Community Park Program Development",Athens-Clarke County, Athens-Clarke County, GA, 1997. Case Studies Greenberg Consultants, "Skyline Park Revitalization Initiative", City and County of Denver and the Downtown Denver Partnership,April 2001. (www.downtowndenver.com) Leccese, Michael, "To Repair or Replace",Landscape Architecture, volume 89, number 12, December 1999: 48-51. Mooney, Patrick, "Revisiting Fishtrap Creek",Landscape Architecture, volume 91, number 9, September 2001: 66-69, 123-127. 93 Planting Duncan H. Wilbur, and Marion B. Duncan, Wildflowers of the Eastern United States, The University of Georgia Press,Athens, 1999. Web Resources www.downtowncever.com/skylinepark.html www.forester.net/sw.html www.harvard.gsd.water/symp What is Low Impact Questions and Answers Development (LID)? Information on the most frequently asked low LID is an ecologically friendly approach to site impact development questions. development and storm water management that Public Safety aims to mitigate development impacts to land, Q. I am aware that in some instances, LID advocates the reduction of street widths and the reduced use water, and air. The approach emphasizes the in- of sidewalks to decrease impervious surfaces. Isn't tegration of site design and planning techniques this a threat to public safety? that conserve natural systems and hydrologic func- A. No. Studies have shown that reduced street widths tions on a site. The practice has been success- still provide all the functions of access, parking, ' .. fully integrated into many municipal development and circulation for residents and emergency Wit. codes and storm water management ordinances vehicles alike. Depending on density, minimizing * . throughout the United States. Specifically, LID the use of sidewalks may help to reduce t r aims to: development costs, increase housing affordability, and reduce impervious surfaces. . • Preserve Open Space and Minimize Land Q. Don't LID storm water management practices Disturbance; increase the likelihood of flooding? • Protect Natural Systems and Processes (drainage A. No. LID designs provide adequate conveyance of ways, vegetation, soils, sensitive areas); storm water by using designs that maintain • Reexamine the Use and Sizing of Traditional Site predevelopment volumes and rates of runoff. Since Infrastructure (lots, streets, curbs, gutters, bioretention areas are designed to completely sidewalks)and Customize Site Design to Each Site; drain within a specified period of time, they do not • Incorporate Natural Site Elements (wetlands, provide breeding grounds for mosquitos. Overflow stream corridors, mature forests)as Design controls within bioretention areas control the risk Elements; and of flooding. • Decentralize and Micromanage Storm Water at its Public Perception Source. Q. Aren't homeowners concerned about maintaining storm water controls on their properties? A. Environmental stewardship is everyone's Municipal , responsibility. Most homeowners view these systems as additional landscaping and once they are aware of the benefits that these systems r provide to local hydrology, few remain opposed. Low Impact Maintenance ■ Q. LID practices sound great, but who maintains all of Development the open space and various storm water controls? .a TOL A. Communities designed using LID practices often rely on a combination of homeowner stewardship mG and maintenance agreements. When designed correctly, most homeowners perceive these Ssystems as value-added builder amenities and actively provide for their maintenance. Would you be interested in saving upwards of$70,000* For More Information •- •residential • one lane Courtyard with Bioretention Areas • Low Impact Development Center D • you know • - designed • maximize Buckman Heights Community http://www.lowimpactdevelopment.org open •• _ • preserve mature • Portland,OR • Prince George's County, Maryland marketable ' command http://www.goprincegeorgescounty.com Are• t most homeowners NAHB Research Center Toolbase Services _• Impact Development practices, bioretention, http://www.tootbase.org as favorable since such practices are viewed as • U.S. EPA additional builder . .. http://www.epa.gov/owow/nps/urban.htmt Did you know that by reducing impervious surfaces, disconnecting run• pathways, infiltration . you . 1k. _• d o • o p o d Cover Photo:R.Arendt 'Assumes paving costs of$15/sq.yd. a:'�Printed on recycled paper with soy ink _ Case Study Somerset is an 80-acre development in Prince George's County, Maryland consisting of -E Grassed Swale and 199 homes on 10,000-square-foot lots. During Narrow its creation, the developer used LID practices Engineering Montgomery County, to reduce the storm water management bur- Redesign 0 $110,000 o . den. By using LID, the developer: Land Reclamation (6 lots x S40,000 Net) o $$240,0001 o Total Costs $2,457,843 $1,54 • Eliminated the need for storm water ponds by 41,46461 lf. using bioretention techniques saving approximately$300,000; " Total Costs 0. (-Land Reclamation i • Gained six additional lots and their associated 3 +Redesign Costs) $2,457,843 $1,671,461 revenues; and ° Total Cost Savings=$916,382 o Reduced finished lot cost by approximately 1 Bioretention ft� Cost Savings Per Lot=$4,604 $4,000. No Native Vegetation Cost Comparison:Conventional Design vs.Bioretention u Y Prairie Crossing Grayslake,IL LID Benefits *r In addition to the practice just making good sense, low impact development - r . offer benefits to a variety V, LID A• 6 4 Municipalities Lot with Bioretention Protect •nal flora and fauna Balance growth needs with environmental protection 1. Reduce municipal infrastructure and utility �7_ F, maintenance costs (streets, curbs, gutters, PL F - i sidewalks, • Increase collaborative public/private •. a• _ . a ships Aerial View of Somerset Development Site Plan,Prince George's County,MD Developers Reduce• • clearing and grading curbs,• Potentially reduce infrastructure costs (streets, Hydrologic Comparison between Conventional . Grassed Swale and Street without Curb and Gutter Storm Water Management and LID •• • -ntially reduce impact and increases tot Hydrologic alterations within the landscape occur whenever land is developed. yields Conventional development approaches to storm water management have used • Increase tot and community marketability practices to quickly and efficiently convey water away from developed areas. Usually these practices are designed to control the peak runoff rate for prede- Environment termined storm events,usually the 2-and 10-year storms.While these systems Preserve integrity of ecological an• biological have worked to some degree,they still have not accounted for the increased systems runoff rates and volumes from smaller, more frequent storms, nor have they addressed the larger watershed functions of storage,filtration, and infiltra- tion. reducing • and toxic toads water bodies In contrast,LID utilizes a system of source controls and small-scale,decentral- ized treatment practices to help maintain a hydrologically functional land- • Reduce impacts to local terrestrial and aquatic scape.The conservation of open space,the reduction of impervious surfaces, plants and animals and the use of small-scale storm water controls,such as bioretention,are just • Preserve trees , • vegetation a few of the LID practices that can help maintain predevelopment hydrological Bioretention Area and Open Space conditions. Photos:Low Impact Development Center IV LOCAL TE CH. V I ALASSISTANCE PROGRAM 2012 CALL FOR PROJECTS Request for Assistance Application Form DEADLINE: 5:00 p.m. on Wednesday,August 1, 2012 This application form is online at http://www.cmap.illinois.gov/lta. You may submit the form: • By email,to psaunders @cmap.illinois.gov • By mail,to the following address: Local Technical Assistance Program CMAP 233 S. Wacker Drive,Suite 800 Chicago, IL 60606 1. Name of Applicant: united City of Yorkville 2. Main Contact for Application: Krysti J. Barksdale-Noble,AICP Community Development Director (Name) 800 Game Farm Road,Yorkville, Illinois 60560 (Address) 630-553-8573 (Phone) knoble @yorkville.il.us (Email) 3.Type of Applicant(please check any that apply): ✓ Municipality County Multijurisdictional group p, Please list the members of the group (including government and nongovernmental organizations): Nongovernmental organization* P Name of local government partner(s): *Applications submitted by nongovernmental organizations must include a letter indicating support from the relevant local government. See the FAQs for more information. 4. What Do You Want to Do? Please tell us what you would like to do in your community, and what assistance is needed. If you have more than one idea, please submit them together in a single application, and include a cover letter that summarizes all of the projects. Please be specific, but also brief (less than 2 pages per project idea)—we simply want to have a basic understanding of what you want to do. CMAP staff will follow-up with you if we need any additional information to fully understand your proposed project. (Please include any additional information that is relevant, either by attaching the physical documents or providing links to online documents.) In 2008, the United City of Yorkville has begun a complete review of its current zoning ordinance and created a Zoning Commission tasked with drafting the proposed comprehensive revisions to the nearly 35-year old document. To date, the Zoning Commission has made wide- ranging updates to a majority of the ordinance including the: purpose and interpretation; definitions; general zoning provisions; administration and enforcement; permitted and special uses; dimensional and bulk requirements; Planned Unit Developments (PUDs); and zoning districts, to bring the ordinance more in line with the current planning practices and actual development processes of the City. Should our municipality be chosen for the Chicago Metropolitan Agency for Planning (CMAP) Local Technical Assistance (LTA) Program 2012 Call for Projects, we would devote the extra staff resources to assist in drafting the proposed new chapters of the zoning ordinance. Such new chapters recommended by the Zoning Commission for inclusion in the revised zoning ordinance are the: Conservation Design District, Historic Downtown Overlay District, Route 47 Overlay District, Off-Street Parking and Loading, Signs and Alternative Energy Systems chapters. The research and drafting of the ordinance regulations and language by the CMAP staff as part of the LTA program would greatly increase our ability to provide an ordinance utilizing the most up-to-date zoning practices and keep on schedule for adoption by 2013. The United City of Yorkville's Zoning Commission meets the fourth (4th) Wednesday of every month to review the proposed staff revisions to the zoning ordinance and plans to hold an open house and citizens' comment session at the conclusion of the revision process, prior to presenting to the City Council at a public hearing to consider for adoption. All previous Zoning Commission meeting agendas, minutes, packets and materials are available to the public on the city's web site at www.yorkville.il.us/gov_mtgs minutes.php. LOCAL TECHNICAL ASSISTANCE PROGRAM 2012 CALL FOR PROJECTS 2012 Open Call for Projects Request Assistance from the GO TO 2040 Local Technical Assistance Program About the GO TO 2040 Local Technical Assistance Program The Chicago Metropolitan Agency for Planning (CMAP),the regional planning organization for the seven counties of northeastern Illinois, offers planning assistance to municipalities, counties, multijurisdictional groups, or nongovernmental organizations within the region. In today's challenging economic and fiscal times, many communities have difficulty allocating enough resources to plan for their futures as proactively as they would like to. At the same time, proactive planning is necessary for our region's continued economic prosperity. For the second year, CMAP is helping to fill this gap by making staff resources and grants available for community-based projects through the GO TO 2040 Local Technical Assistance(LTA) program. The LTA program is meant to help implement GO TO 2040, the regional comprehensive plan. Recognizing the central role of communities in shaping our region's future,the plan calls for CMAP and other groups to support local planning projects. LTA gives communities the opportunity to request CMAP's assistance on important local planning projects of many types. The program is made possible through a three-year$4.25 million award to CMAP from the U.S. Department of Housing and Urban Development (HUD). Most assistance will be in the form of staff time. Applicants that would prefer to receive grant funds should consider applying for funding through CMAP's Community Planning program —see http://rtachicago.com/community-planning/community-planning.html for more details. Eligible Applicants Assistance will be provided to municipalities, counties, multijurisdictional groups, or nongovernmental organizations (though in the case of nongovernmental groups, participation of the appropriate local governments is also required). Eligible Project Types The Local Technical Assistance program will support planning activities that advance the implementation of GO TO 2040. Overall, local planning projects that address issues of transportation, land use, and housing in some way are eligible for assistance;those that treat these issues comprehensively and also address the natural environment, economic growth, and community development are ideal. CMAP encourages the submission of ideas from multijurisdictional applicants. Examples of areas in which assistance will be provided include, but are not limited to: • Preparation or updates to a local comprehensive plan, either in whole or in part. This could include expanding an existing plan to cover new topics such as energy and water conservation, local food, public health, workforce training, arts and culture, and others. • Revisions to ordinances or other land use regulations. This could include revising outdated ordinances that are inconsistent with the comprehensive plan, updating codes to address water and energy conservation, updating parking regulations in a downtown, or many others. • Activities that help to implement previously-adopted plans. For example,this could include advancing Transit Oriented Development (TOD) plans or other small-area plans by making recommended ordinance changes, analyzing financing needs, or similar activities. • Studies or specific plans related to important local issues. This could include planning for stormwater management in areas that experience flooding, projecting future housing supply and demand, addressing parking challenges, identifying open space needs, and others. • Projects that involve multijurisdictional coordination,such as planning for housing cooperatively across several communities, planning for improvements along a transportation corridor, preparing watershed plans that cross municipal boundaries, or pursuing projects that help to implement previous multijurisdictional plans. • Assisting with public participation related to challenging local projects, including meeting facilitation or communication of complex planning issues to the public. The LTA program is geared toward planning activities at a larger scale than an individual site. Some site- level projects may be undertaken, but these will generally be in the context of larger planning activities. Further information on project types,with descriptions of current LTA activities, can be found at CMAP's LTA web page, http://www.cmap.illinois.gov/lta. Non-Eligible Project Types Project phases such as land acquisition, engineering, or capital investment, are not intended to be pursued through the GO TO 2040 Local Technical Assistance program. How to Apply Applicants should submit the simple"Request for Assistance"form by mail or email by the deadline: 5:00 p.m. on August 1, 2012. Submittal by email is encouraged. Review Process It is expected that there will be more requests for assistance than can be accommodated. Staff will review requests for assistance with CMAP's working committees, as well as other technical assistance providers and funders. Below are criteria that will be used to evaluate the requests: • Alignment of the project with the recommendations of GO TO 2040 • Local need for assistance • Feasibility and ability to implement • Collaboration with other groups, including neighboring governments and nongovernmental groups • Input from relevant Counties and Councils of Government(COGs) • Geographic balance Selected projects will be announced in October 2012. All applicants will be notified via letter and email as to whether or not their project was selected. Upon selection, applicants will be assigned a CMAP contact who will work with the designated applicant to scope out the details of the project. For additional information Please contact Pete Saunders at psaunders @cmap.illinois.gov or (312) 386-8654. Program information and the Request for Assistance form are available online at this link: http://www.cmap.illinois.gov/lta Frequently Asked Questions (FAQs) When are applications due? Applications are due August 1, 2012. This seems like a really simple application, am 1 missing something? No,you're not missing anything. Please tell us what you would like to do in your community,and what assistance is needed. Please be specific, but also brief(less than 2 pages)—we simply want to have a basic understanding of what you want to do. CMAP staff will follow-up with you if we need any additional information to fully understand your proposed project. Is a funding match required? No. Can 1 submit more than one idea? You may submit more than one idea.There can be multiple project requests on one application. If this is the case, please include a cover letter or cover page clearly indicating the different ideas included within the application. Who is eligible to apply? Staff assistance will be provided to municipalities, counties, interjurisdictional groups, or nongovernmental organizations (though in the case of nongovernmental groups, participation of the appropriate local governments is also required). If you are applying for a project in the City of Chicago, the City of Chicago Department of Housing and Economic Development will be involved in project selection. What types of projects are eligible? The Local Technical Assistance program will support planning activities that advance the implementation of GO TO 2040. Overall, local planning projects that address issues of transportation, land use, and housing in some way are eligible for assistance;those that treat these issues comprehensively and also address the natural environment, economic growth, and community development are ideal. What projects are not eligible? Project phases such as land acquisition, engineering, or capital investment, are not intended to be pursued through the GO TO 2040 Local Technical Assistance program. What types of projects has CMAP worked on in the past? After our first year we've worked on: • Comprehensive plans • Housing policy studies • Corridor plans • Neighborhood/Subarea plans • Sustainability plans • Water conservation studies Please visit the project website, www.cmap.illinois.gov/lta,for more detail. Are any types of projects particularly targeted for this year's LTA program? As noted earlier, many types of projects are eligible for the LTA program. Within these, projects that involve multijurisdictional coordination, or involvement of nongovernmental partners, are priorities. Also, projects that build on past work by CMAP are also more likely to find success. Projects that implement the recommendations of past multijurisdictional projects–like watershed plans, or Homes for a Changing Region projects, or others–are good fits for the program. Also,those that implement model codes and ordinances produced by CMAP—such as water conservation or parking—will also have some advantage. Are any types of projects not targeted? All projects listed as eligible can be submitted. However, please keep in mind that the process is quite competitive, and projects will be evaluated in context. For example, updating a fairly recent comprehensive plan will be a lower priority than updating a much older comprehensive plan or preparing the first-ever comprehensive plan for a community. (During the first round of applications, comprehensive plan updates were targeted primarily to communities whose plans were more than 15 years old.) Therefore, projects involving updates to plans that are relatively new—while they are eligible—will be less likely to be selected than those that update older or lower-quality plans. How do we demonstrate local support of the application? For suburban jurisdictions, a letter of support from a Mayor or Village Manager is sufficient. For City of Chicago applicants, a letter of support from the Mayor's Office or from the Department of Housing and Economic Development (DHED) will do. Kathy Dickhut (Kathleen.Dickhut @cityofchicago.org) should be the first point of contact for nonprofit Chicago-based applicants. Who is funding this program? The LTA program is made possible through a $4.25 million award to CMAP from the U.S. Department of Housing and Urban Development(HUD). It is also supported through funds from the U.S. Department of Transportation. When will you be announcing the selected projects? Selected projects will receive final approval at the CMAP Board Meeting on Wednesday, October 10, 2012. 1 applied last year and was not selected, can I reapply? Yes. CMAP will be contacting you to ask if you would like to submit the same application for consideration or make any changes. Please note that this year will be quite competitive, so an application that was not selected last year is not guaranteed to be selected this year either. How will projects be evaluated? There are six criteria, listed earlier in this document. Applications will be reviewed for how well they align with these criteria. What is the difference between the LTA program and the Community Planning program? Both programs have the same purpose—to implement GO TO 2040 by directing planning resources to local governments. The LTA program primarily provides CMAP staff assistance; the Community Planning program provides either grants or assistance from consulting firms. Also,the Community Planning program requires that project has significant transportation-related elements. Because the Community Planning program involves the commitment of funding, rather than staff resources, it also involves a longer and more detailed application form. How should I know whether to apply for assistance through the LTA program or the Community Planning program? If you are fairly certain you want to hire a consultant for your project, rather than using CMAP staff resources,you should apply to the Community Planning program, because the LTA program primarily involves staff assistance from CMAP. The Community Planning program also is more restrictive, in a number of ways. For the Community Planning program,the applicant needs to provide a much more thorough description of their project; the application form is more detailed; the project must include transportation components; and non-governmental organizations are not eligible applicants. For the LTA program,the applicant can provide more general ideas; eligibility is broader; and CMAP will work with the applicant to figure out the most suitable project to meet their needs. Please also note that because it is less restrictive, the LTA program is also likely to attract more applications—so applicants to the Community Planning program may have a better chance of success. Can 1 apply to both the LTA program and Community Planning program for the same project? Yes,this is fine. If you are interested in this, please fill out a complete Community Planning program application. Within the LTA "Request for Assistance"form,you can simply direct CMAP to refer to the Community Planning program application. Can I request money to cover staff time at my organization? Sorry, but no. If any financial commitment from CMAP is involved, it will be to hire an external contractor through a competitive process. Can I apply for a second project if I was selected in the first round? Yes. Your application for a second project will be considered along with all of the other projects that are received. Your application is not guaranteed to be successful, but demonstrating how the second project builds on the first project will increase your chance of success. How competitive is CMAP expecting the application process to be? Very. During the first year's call for projects, CMAP received over 220 project ideas from 130 applicants. Approximately 60 of these applicants were selected. This year, a similar number of applications is expected to be received, but only 25-30 projects will be selected. This is because CMAP selected two years'worth of projects in the first round of projects, and is only selecting one years' worth during this application cycle, since some of the initial projects are still underway. Who can 1 contact if 1 still have questions? Pete Saunders at psaunders @cmap.illinois.gov or 312-386-8654 How can 1 submit my application? • By email,to psaunders @cmap.illinois.gov • By mail,to the following address: Local Technical Assistance Program CMAP 233 S. Wacker Drive,Suite 800 Chicago, IL 60606