Big Darby Accord Watershed Master Plan

Prepared for City of Columbus Pleasant Township City of Hilliard Prairie Township Grove City Washington Township Brown Township Village of Harrisburg Norwich Township Franklin County

FINAL / JUNE 2006 THIS PAGE LEFT INTENTIONALLY BLANK Acknowledgements

The Accord planning process was City of Columbus Brown Township made possible through the Michael Coleman, Mayor Gary Dever, Trustee coordination, input and Matthew Habash, City Council Pamela Sayre, Trustee contribution of many people and President Ronald Williams, Trustee agencies that deserve recognition. Michael Mentel, City Council Kevin Boyce, City Council Norwich Township Jurisdictions Mary Jo Hudson, City Council Chuck Buck, Trustee The following jurisdictions and Maryellen O’Shaughnessy, City Council Larry Earman, Trustee their elected leadership joined in Patsy Thomas, City Council James Rice, Trustee the conception, funding and Charleta Tavares, City Council development of the Accord. They Pleasant Township supported the Accord through Franklin County Keith Goldhardt, Trustee allocation of funding, staff time, Paula Brooks, Commissioner – President Walter W. Krebs, Trustee facilities and other resources. Mary Jo Kilroy, Commissioner Dale Worthington, Trustee Dewey Stokes, Commissioner Dean Ringle, County Engineer Prairie Township Douglas Stormont, Trustee City of Grove City Stephen Kennedy, Trustee Prepared by Cheryl Grossman, Mayor Nichole Schlosser, Trustee EDAW Inc Richard Lester, Council President Ted Berry, City Council Washington Township In collaboration with Larry Corbin, City Council Denise Frantz King, Trustee MSI Design Maria Klemack, City Council Gene Bostic, Trustee EMH&T Richard ʺIkeʺ Stage, City Council Charles W. Kranstuber, Trustee Ohio State University Extension Squire, Sanders & Dempsey LLP Village of Harrisburg Group of Four (G4) Schottenstein Zox & Dunn Cindy Taylor, Mayor This appointed group guided the Trans Associates April Porter, Village Council President Accord process as representatives Rodney Collins, Village Council of the member jurisdictions. Ellen Dawson, Village Council Rebecca Peterson, Village Council Representing Townships Janet Ray, Village Council Tracy Hatmaker, Prairie Township Richard Smith, Village Council Administrator

City of Hilliard Representing the City of Columbus Don Schonhardt, Mayor Michael Reese, Deputy Chief of Staff Bill Uttley, City Council President Kim Allison, City Council Representing Franklin County Scott Brown, City Council Lee Brown, Planner Mike Cope, City Council Dana Peacock, City Council Representing Suburban Communities Tim Roberts, City Council Clyde Seidle, Hilliard Director of Brett Sciotto, City Council Public Service

Project Coordinator Kevin Wheeler, City of Columbus

B I G D A R B Y A C C O R D A C K N O W L E D G E M E N T S / 1 Stakeholder and Staff Representatives The following are among the many • Rob Pritchard, Representative stakeholder representatives and Property Owner agency staff that contributed to the • Tim Richardson, Brown Township plan’s development. • Anthony Sasson, The Nature • Cheryl Roberto, City of Columbus Conservancy • Vince Papsidero, City of Columbus • Erin Sherer, OEPA • Kusi Akuoko, Franklin County • Mark Sherman, Franklin County • Susan Ashbrook, City of Columbus • Tom Shockley, Franklin County • John Bain, Representative • John Tetzloff, Darby Creek Property Owner Association • Guy Blauser, Representative • Brian Williams, American Farmland Property Owner Trust • Don Brosius, Township • Robert Williams, Franklin County Representative • Planning Division, City of Columbus • Don Brown, Franklin County • City Attorney’s Office, City of • Steve Campbell, City of Columbus Columbus • Pete Cass, City of Columbus • Division of Sewerage of Drainage, • Beth Clark, formerly of City of City of Columbus Columbus • Pam DeDent, City of Hilliard Meeting Space • Todd Dieffenderfer, City of Both Hilliard City Schools and Columbus South‐Western City Schools were • Neil Distelhorst, Representative very generous in providing meeting Property Owner space for public meetings. Each • Dan Dudley, Ohio Environmental district hosted two public meetings Protection Agency (OEPA) with a total attendance of • Lee Edwards, Representative approximately 600. Property Owner • Jennifer Fish, Franklin Soil and Water In addition, Franklin County Conservation District Engineer Dean Ringle hosted • Bob Gable, Ohio Department of numerous stakeholder meetings Natural Resources throughout the process. • Mike Galloway, OEPA • Tim Hamilton, Hilliard Schools Meeting Sponsorship • Linn Horn, Representative Property In addition to the four public Owner meetings held during the Accord • Paul Lambert, Representative process, the following Property Owner organizations sponsored a panel • Joe Martin, Representative discussion on the effort: Property Owner • 1,000 Friends of Central Ohio • Nan Merritt, Affordable • Building Industry Association Housing Trust of Ohio • Dan O’Brien, Property Owner • Darby Creek Association • John O’Meara, Metro Parks • Tammy Noble, formerly of Franklin County • Malcolm Porter, Building Industry Association

2 / A C K N O W L E D G E M E N T S B I G D A R B Y A C C O R D Contents

Executive Summary 4.0 Land Use and Development Policies 4.1 General Development Practices 4.1 1.0 Introduction 4.2 Environmental Components 4.1 1.1 Formation of the Accord 1.1 4.2.1 Riparian Corridor Protection 4.1 1.2 Plan Principles 1.4 4.2.2 Wetland Preservation and Mitigation 4.5 1.3 Planning Process 1.6 4.3 Open Space 4.6 1.4 Report Format 1.7 4.4 Conservation Development 4.8 4.5 Rural Development 4.9 2.0 Plan Framework 4.6 Town Center 4.10 2.1 By-Right Zoning 2.1 4.7 Stormwater Management 4.12 2.2 Infrastructure Considerations 2.4 4.7.1 Stormwater Quantity Control 4.12 2.3 Sensitivity Analysis 2.11 4.7.2 Groundwater Recharge Criteria 4.12 2.4 Water Quality and Biology 2.14 4.7.3 Stormwater Quality Control 4.13 4.7.4 Floodplain Management 4.14 3.0 Land Use Plan 4.8. Stormwater Best Management Practices (BMP) 4.15 3.1 Conservation Strategy 3.2 4.8.1 BMP Planning Process 4.15 3.1.1 Conservation Strategy Components 3.4 4.8.2 System Ownership and Maintenance 4.17 3.2. Existing Land Use 3.8 4.8.3 BMP Toolkit 4.19 3.3 Proposed Land Use 3.13 4.9 Utilities 4.26 3.3.1 Town Center 3.15 4.9.1 Centralized Sewer 4.26 3.3.2 Conservation Development 3.17 4.9.2 Non-centralized Sewer 4.27 3.3.3 Other Residential Uses 3.18 4.10 Transportation 4.28 3.3.4 Mixed Use 3.18 4.11 Trails and Greenways 4.29 3.3.5 Agriculture 3.19 3.3.6 Transportation Considerations 3.19 5.0 Implementation 3.4 LEED Principles of Design 3.20 5.1 Big Darby Accord Advisory Committee 5.1 3.5 Water Quality 3.20 5.2 Development Review Process 5.2 3.5.1 Water Quality Monitoring 3.20 5.2.1 Rezoning and Site Development Review Process 5.3 3.5.2 Storm Water Management 3.23 5.2.2 Detailed Review Process 5.5 3.5.3 Performance Goals 3.28 5.2.3 Development Review Checklist 5.7 3.6 Stream Restoration 3.29 5.3 Other Coordinated Activities 5.8 3.6.1 Hellbranch Run Watershed Opportunities 3.30 5.3.1 Monitoring 5.8 3.6.2 Other Restoration Opportunities 3.31 5.3.2 Town Center Master Plan 5.12 3.6.3 Stream Restoration Techniques 3.31 5.3.3 Community Facilities 5.14 3.6.4 Funding for Stream Restoration Activities 3.34 5.4 Open Space and Land Protection Programs 5.17 3.6.5 Regional Stream Restoration 3.34 5.4.1 Land Conservation Tools 5.18 3.7 Floodplain Management 3.35 5.4.2 Recommended Conservation Programs 5.18 5.5 Revenue 5.24 5.5.1 Key Assumptions 5.24 5.5.2 Projections 5.25 5.5.3 Summary Revenue Considerations 5.26 5.5.4 Use of Revenue 5.26 5.6 Early Actions 5.26

Appendices A. Water Quality Modeling/Pilot Study B. Funding Sources C. Reference Information/GIS Sources D. Development Review Checklist E. Stormwater Utility F. Alternative Wastewater Systems

B I G D A R B Y A C C O R D C O N T E N T S / 1 THIS PAGE LEFT INTENTIONALLY BLANK Executive Summary

The Big Darby Watershed in central Ohio is one of the most biologically Mission Statement diverse aquatic systems in the Midwest, home to 38 state and The Big Darby Accord consists of local governments within the Franklin federally listed aquatic species. Big County area of the Big Darby Creek Watershed. The mission of the Big Darby Accord is to cooperatively develop a multi-jurisdictional plan and and Little Darby creeks have been accompanying preservation and growth strategies, capable of designated as State and National implementation, oversight, and enforcement, which are designed to: Scenic Rivers. • Preserve, protect and improve, when possible, the Big Darby Watershed's The Big Darby Accord Plan has unique ecosystem by utilizing the best available science, engineering and been prepared collaboratively land use planning practices; among ten jurisdictions within the • Promote responsible growth by taking measures to provide for adequate Franklin County portion of the public services and facilities and promote a full spectrum of housing watershed, covering an area 84 choice, as well as adequate educational, recreational, and civic square miles in size. The Big Darby opportunities, for citizens of each jurisdiction and for Central Ohio; Accord Plan is intended to serve as a multi‐jurisdictional guide for • Create a partnership that recognizes the identity, aspirations, rights, and development and conservation. The duties of all jurisdictions and that develops methods of cooperation Plan represents a long‐term vision among the partners through means which include the cooperative and general land use plan for the utilization of public services and facilities; and future that brings together multiple • Capitalize on the results of other efforts by considering local interests in an effort to protect and comprehensive plans, as well as the work of the Environmentally preserve the watershed while Sensitive Development Area External Advisory Group, the Hellbranch providing guidance for managed Watershed Forum, the 21st Century Growth Policy Team, and other local growth. The Plan allows for the planning and zoning efforts, in the development of the plan. lifting of a development moratorium that has been in place three and a half years. Total Maximum Daily Load (TMDL) A Mission Statement and Plan The Plan builds upon previous Report for the Big Darby Watershed, Principles have guided this planning efforts and studies and the Hellbranch Watershed planning effort and will continue to including, but not limited to, the Forum. It is the goal of the Accord lead Accord jurisdictions through External Advisory Group (related that each jurisdiction work towards plan implementation. to the Environmentally Sensitive adoption and implementation of Development Area), the Ohio EPA the Plan and its provisions.

Big Darby Creek Source: Metro Parks/Jim Murtha

B I G D A R B Y A C C O R D E X E C U T I V E S U M M A R Y / i Conservation Category Acres Protected 4,310 Existing 6,131 Tier 1 5,790 Tier 2 1,885 Tier 3 7,150 Total 25,266 Acreages of Conservation Categories Conservation Categories Acreages

Big Darby Creek Source: The Nature Conservancy

Conservation Strategy Plan Framework

A system of Tiers identifies land Review and analysis of available The Plan drivers led to the creation areas of protection based on unique information resulted in the of a general land use plan that environmental resources that were identification of “plan drivers” promotes a sustainable land use identified during the environmental which affect the amount, location pattern and locates the highest sensitivity analysis. A majority of and type of development amount of development in areas the sensitive features are associated recommended in the Plan. that are less sensitive and within with areas of high potential for close proximity of centralized groundwater and surface water Plan drivers include the level of sewer and regional transportation flow exchange, areas of high development that is currently networks. A conservation strategy groundwater pollution potential, permitted in the planning area based on natural resource features floodplains, wetlands, and stream (referred to as by‐right); and a desire to create a connected corridor zones. The Tiers also accessibility and capacity of green infrastructure network encompass existing parks and centralized sewer and roadway balances development with the goal easements totaling over 7,000 acres systems; environmental conditions of conserving almost 25,000 acres of as well as areas that are already related to sensitive natural land. To achieve the Mission, both protected under current regulations resources; and water quality and elements ‐ development and like floodplains and the calculated aquatic habitat conditions related to conservation ‐ need to be pursued stream protection zone. The goal of current and proposed land uses. simultaneously. the Accord is to protect the Tiers through development policies and Accord Plan Principles regulations, and proposed • Protection of environmentally sensitive areas voluntary programs and incentives • A general land use plan that balances environmental protection and for conservation. responsible growth • A general land use plan that recognizes existing sewer and waste water Tier 1 includes land within the 100‐ treatment capacities, while taking into account the rights accorded year floodplain, wetlands, and watershed landowners under current zoning critical groundwater recharge and • Growth will be served by adequate public facilities, particularly pollution potential zones. Tier 2 central sewer includes areas with highly erodable • A development policy that provides for mechanisms to acquire soils and wooded areas of greater environmentally sensitive areas than 3 acres in size. Tier 3 is • A memorandum of understanding among Accord members to considered important for protection implement the agreed upon plan because these areas allow for the • Development without the condition of annexation creation of linkages among all the components of the land • Mechanisms for cooperative revenue sharing among Accord members conservation strategy ‐ as well as • Water quality, biological integrity, and adaptive management suitable areas for parkland.

ii / E X E C U T I V E S U M M A R Y B I G D A R B Y A C C O R D Development Strategy • Higher density development in a The general land use plan proposes The general land use plan, which is new town center between Interstate a variety of new land use categories based on a development level that 70 and US Route 40 (West Broad for the planning area. In addition to is currently permitted by local Street) that would be served by conservation areas, principle land centralized sewer. zoning codes, identifies an use categories include conservation • Additional areas of higher density development and a new mixed‐use additional 20,000 dwelling units of adjacent to Hilliard and the City of development. When combined with Columbus along the eastern edge of Town Center. the estimated existing population, the study area that would be served the long‐term (30 years) build out by centralized sewer. Conservation Development for the planning area is about • Areas of conservation development Conservation development, also 100,000 residents. Figure 1.0, within Brown, Prairie and Pleasant sometimes referred to as cluster located at the end of this executive Townships that cluster development development, is recommended as which are served by alternative summary, identifies the proposed the preferred land use pattern to community‐based sewage treatment. protect the area’s environmental general land use plan for the Big • Site and regional‐level application of Darby Accord planning area. To stormwater best management features through open space set manage this growth in a manner practices (BMP’S) to control asides and to protect the rural that protects water quality and stormwater quantity and quality so character of the area. The Plan aquatic habitat, the proposed plan that it does not adversely affect the identifies two conservation is guided by several key concepts: health of the watershed and meets development land use categories; Ohio EPA requirements for pollutant both require that 50% of a loadings for Total Suspended Solids, development site be placed in a Nitrogen and Phosphorus. perpetual easement that is managed in a natural state. In the Proposed Generalized Land Use Categories Acres Percent Hilliard expansion area, which will Agricultural Use 3,356 6% receive centralized sewer, Commercial 196 0% conservation development at 1 Industrial 50 0% dwelling unit per acre is Public / Semi Public 1,053 2% recommended providing for up to Mixed Use 357 1% 2,000 dwelling units. In Brown, Res Conservation Devp 50% Open Rural densities 9,406 17% Prairie and Pleasant Townships, Res Conservation Devp 50% Open 1 du/ac 1,189 2% conservation development at Rural Residential 1,026 2% permitted rural densities is Rural Estate 4,805 9% recommended. New standards and regulations pertaining to siting and Suburban Low Density 0.5-3 du/ac 149 0% design criteria, operator and Suburban Medium Density 3-5 du/ac 4,073 7% monitoring requirements, and Urban Medium Density 5-8 du/ac 130 0% efficiencies of alternative Urban High Density 8+ du/ac 447 1% community‐based sewage Special Residential LEED 328 1% treatment systems will guide rural Town Center* 1,825 3% conservation developments. Golf Course** 729 1% Incentives to encourage stream Existing Park** 6,266 11% restoration and additional open EC Protected 4,334 8% space set asides are recommended. Tier1 5,600 10% Tier2 1,850 3% Conservation developments should Tier3 7,160 13% reinforce the rural character of the Roads & Transportation*** 1,701 3% watershed. Housing types should 56,029 100% be varied within developments and encourage creativity to meet the Proposed Land Use Categories *Excludes identified Conservation areas in Town Center (about 675 acres) needs of mixed incomes. **Excludes Conservation protected area The location of open space in ***Calculation considers only major roads. conservation developments should

B I G D A R B Y A C C O R D E X E C U T I V E S U M M A R Y / iii be dictated by the location of service availability. Development Policies environmentally sensitive features, within the Town Center should and contiguity and connectivity of follow design standards and The Plan identifies supporting existing open space features to help guidelines that are developed in a policies that each jurisdiction achieve a green infrastructure more detailed planning effort. A should adopt to ensure the network. The design of minimum base density should be watershed is protected. These conservation developments should established to allow for 8 to 15 policies are more fully explained in be flexible to reserve the best dwelling units per acre. the Big Darby Accord Plan. Major available soils on the site for policy recommendations associated community‐based sewage Water Quality with environmental components, treatment. conservation development, the The water quality modeling Town Center, open space, water For larger lot developments that analysis was successful in quality, best management practices occur outside of conservation duplicating the results from the and sewer service are summarized developments, local jurisdictions TMDL study, in particular for the below. should encourage at least 50% of Hellbranch Run watershed. Water the site be placed in a conservation quality modeling of the proposed Environmental Resources easement to ensure proper care and Big Darby Accord general land use The main goals of the Big Darby native vegetative features. plan shows there will be a Accord planning effort are to reduction in the level of specified preserve and protect areas that Town Center pollutants that are contained in contribute the most to water quality The intention of the Town Center stormwater runoff and discharged and to improve the overall aquatic zone is to create a sustainable and to the Hellbranch Run or directly to habitat within the Franklin County highly desirable mixed‐use area the Big Darby Creek main stem. portion of the Big Darby watershed. that includes a full range of The Ohio EPA TMDL sets specific These areas, associated with Tiers 1, residential, retail, office and public targets for reductions in loadings of 2 and 3, in some cases already have uses including parks and open Total Suspended Solids and protective status related to state or space within a 2,500 acre zone. The Phosphorus at 95% and 81% federal regulations. The Plan Town Center is envisioned as a respectively. The general land use recognizes these requirements and walkable village that includes retail plan achieves a significant provides additional guidance. Key uses facing key streets to create a improvement in the direction of Plan provisions include the lively and visually appealing reaching Ohio EPA targets protection of riparian corridors community. attributed to conservation strategy through the application of a stream and land use pattern. corridor protection zone (SCPZ) The Town Center core should be a and reinforcing the protection of safe, attractive, efficient, walkable To achieve the goals of the TMDL, existing wetlands. The SCPZ area with convenient connections to the Plan identifies appropriate and precludes certain activities from residential neighborhoods and innovative best management occurring within a certain distance nearby transit. The Town Center’s practices (BMPs) for site of all stream channels. In addition, outer edges should be designed in a development in the form of a BMP the Plan recommends preserving manner that allows for a transition toolkit. A BMP planning process is existing wetlands to the extent to surrounding uses. The Town also proposed to provide guidance possible. Any mitigation required Center should evoke special in determining the appropriate in meeting the needs of characteristics that set it apart from application for site development. environmentally sensitive resources its surroundings and contribute to The use of Low Impact should create stream and wetland its individuality. Development (LID) design restoration opportunities, or other techniques is recommended to similar benefits. The City of Columbus has reduce the amount of impervious identified an initial sewer capacity cover on a site and allow for more Conservation Areas for the Town Center of 5,000 natural areas and infiltration. The Plan recommends requiring equivalent dwelling units. The total permanent easements for areas that amount of development may are intended for conservation, increase depending on sewer including stream corridor

iv / E X E C U T I V E S U M M A R Y B I G D A R B Y A C C O R D protection zones and land that is set required best management within the downstream watershed aside as part of conservation practices to meet water quality area. The Plan outlines an eight step development requirements. goals, environmental policies, and BMP planning process to select Easements can provide economic the availability of utilities. The Plan appropriate BMPs that address benefits to property owners. All recognizes that flexibility may be both the proposed development easements should be held jointly by needed to meet all requirements and the pollutants of concern listed home owners associations, and suggests incentive in the TMDL. Practices such as governmental entities or opportunities to help reach the green roofs, pervious pavement, conservation groups to ensure that overall goals of the Plan. rain water harvesting, filtration they are properly maintained and devices, hydrodynamic devices, managed over the long term. Stormwater bioretention, grass channels, dry Consistent guidelines for the Development in the Accord swales, wet swales, infiltration maintenance and care for privately planning area will need to meet a basins, infiltration trenches, dry held open space lands or land held new standard in order to meet wells, and underground detention within easements will need to be water quality goals of the Ohio EPA are discussed. It is important to developed to ensure the areas are and of this Plan. Stormwater review stormwater policies as planted with native vegetation. management policies for the Big science, technologies, industry, and Developers should be required to Darby Accord Plan are tied to design will likely evolve. work with Franklin Soil and Water maintaining and improving water Conservation District and the local quality and aquatic life use Utilities jurisdiction to develop a planting attainment within planning area Centralized sewer will be provided plan for any open space easement, watercourses. The Plan to the Town Center and the plant the initial cover and ensure a recommends a regional approach to identified development corridor successful outcome for a specified stormwater management in the within the Hilliard expansion area. number of years. Town Center to provide sufficient Current capacity constraints limit treatment and pollutant removal. development in the proposed Town Development Center to 5,000 equivalent dwelling Policies related to development are Best management practices are units and 2,000 dwelling units in aimed at creating a more structural or non‐structural the Hilliard expansion area. sustainable land use pattern that practices, management practices, or Centralized sewer service will also can be served by infrastructure, a combination of these techniques, be provided to the LEED area east protects sensitive resources, and that minimize the impacts of of Alton and Darby Creek Road. create places that increase the agricultural or urbanized land uses Capacity exists for approximately quality of life for residents and on water quality by removing or 1,400 equivalent dwelling units in visitors. The Plan discourages reducing pollutants. BMPs capture this area. Central sewer service may conventional subdivisions, which and treat pollutants found in runoff also be provided in a manner are inconsistent with the goals of and manage the frequency, volume consistent with the Accord general the Plan, and proposes and energy of the runoff so that land use plan to some sites closer to development patterns that cluster water resources are not degraded. the existing system that were housing in conservation previously annexed or are zoned developments or in a new mixed‐ The Plan summarizes information for development. use Town Center. The Plan on design criteria, benefits and encourages the application of limitations, pollution removal To avoid a proliferation of Leadership in Energy and efficiency, site design factors, depth household sewage treatment Environmental Design (LEED™) to the water table, and the scale at systems (HSTS), other areas would building principles, particularly which each BMP is most effective. utilize alternative community‐ LEED™ Neighborhood Design based sewage systems such as drip (ND) principles which are under Planning for stormwater or spray irrigation. Management, development. management BMPs within a operation, design, maintenance and development begins with the other requirements for community‐ Development proposals will need collection of data on the local based systems are being evaluated. to include an evaluation of receiving waters and information environmental site conditions, regarding pollutants of concern

B I G D A R B Y A C C O R D E X E C U T I V E S U M M A R Y / v Implementation

Implementation of the Big Darby Accord will require coordinated effort among a number of key stakeholders, including local governments, state agencies, landowners, conservation organizations, and developers. A Memorandum of Understanding between the jurisdictions is being pursued to solidify the commitment to work together to implement the Plan. To help jump start efforts, the Accord jurisdictions should consider appointing or jointly hiring staff to coordinate efforts.

Development Review and Coordination Adoption of the Plan will require updates to local comprehensive plans, zoning and subdivision regulations, and related policies. These efforts should be coordinated whenever possible to promote efficiency. Future zoning and site development review processes must be consistent and apply evenly to all areas of the planning Various Roles and Responsibilities for Plan Implementation area. The Plan recommends the formation of a Big Darby Accord Advisory Panel to fulfill an oversight function to the review recommendation regarding the infrastructure and utilities, land process and create a mechanism for proposal to the local jurisdiction. acquisition and conservation, collaboration. The recommended Final approval resides with the stream restoration, community structure is similar to the Rocky local jurisdiction. facilities, stormwater management, Fork‐Blacklick Accord Panel. and water quality monitoring. Development and rezoning Funding Accord jurisdictions should allow proposals will proceed through Funding the Plan will require flexibility in meeting plan review at the local jurisdiction level several existing and new requirements, particularly if aided by the use of a development mechanisms including a new opportunities arise for regional review checklist that identifies community authority, tax solutions such as large scale stream requirements for Accord Plan increment financing (non‐school) restoration, regional stormwater consistency. The Big Darby Accord program, and a $2,500 per unit facilities, and alternative Advisory Panel will review developer contribution. Based on a community based sewage systems. completed development and number of assumptions, these zoning proposals prior to local mechanisms could collectively Town Center Master Plan jurisdiction technical review. generate upwards of $430 million A recommendation of the Big Following the technical review and (present value) dollars over time. Darby Accord Plan is to prepare a review of staff reports, the Big Revenues will also be leveraged detailed master plan for the Town Darby Accord Advisory Panel will with other available resources to Center area as identified within the provide a non‐binding fund plan improvements related to Plan. A master plan would help

vi / E X E C U T I V E S U M M A R Y B I G D A R B Y A C C O R D establish a more specific vision for To allow for ongoing study and to Early Actions the development of the Town adapt to changes over time, the Center and would provide a Plan recommends establishing a The Accord Plan is a living detailed set of recommendations comprehensive water quality document that, over time, will including level of development, monitoring program at both the need to be updated. Several of the infrastructure requirements, design watershed level and the programs recommended in the Plan guidelines, and phasing. The development site level. The are intended to provide feedback master plan should address public primary purpose of the watershed that will be used to adapt policies, and private properties within the level monitoring is to ensure that programs, and standards to ensure Town Center and incorporate the the aquatic life use designations for that actions today and in the future adjacent areas as part of the all reaches of a stream are being are still meeting the Mission of the analysis to ensure the Town Center met. The purpose of the Accord. New technologies related complements and is compatible development site level monitoring to best management practices, new with the surrounding areas. is to ensure development sites are tools and open space programs may not exceeding determined arise. Several early actions are There are a number of steps allowable release rates for the identified for the Accord required in the preparation of the pollutants of concern as defined by jurisdictions to move the planning master plan. At a minimum Brown the Ohio EPA in the TMDL. To process into action. These actions and Prairie Townships should establish the protocols, process and are further refined in an emerging lead the master plan effort, in details of the monitoring program Memorandum of Understanding coordination with other members (and to help establish goals, among the jurisdictions: of the Accord. consistency and coordination for • Adopt the Plan (1‐4 months) stream restoration efforts), an • Complete and Adopt a Memorandum of Understanding (1‐4 months) Programs Environmental Monitoring Group • Update local regulations (2‐6 months) The Plan identifies a variety of new (EMG) should be established with • Establish a Darby Accord Advisory programs for reaching the goals of representatives from The Ohio State Panel (4‐6 months) the general land use plan and University, Ohio EPA, Ohio • Identify staff resources to facilitate creating a conservation network of Department of Natural Resources, implementation of plan elements (6‐9 25,000 acres. Priorities for Franklin Soil and Water months) conservation efforts should be Conservation District, and one • Perform facilities planning for linked to the Tiers with acquisition outside conservation group services (6‐12 months) • Initiate Town Center Master Plan efforts focused on Tiers 1 and 2. The representative. The EMG should process (6‐12 months) Accord should work closely with prepare a State of the Darby” report • Set up Community Authority and organizations like Metro Parks, the every two to five years to report on non‐school TIF (6‐18 months) Nature Conservancy (TNC), Darby water quality trends within the • Begin an environmental monitoring Creek Association, Ohio watershed compared to the TMDL program (6‐18 months) Department of Natural Resources and Plan goals. This report should • Continue public education and (ODNR), Franklin Soil and Water state concerns and identify any outreach (ongoing) Conservation District, Natural recommended action for mitigating Resources Conservation Service impacts. The Big Darby Accord Plan has (NRCS) and The Ohio State brought together ten jurisdictions University (OSU) to provide and created a Plan that serves as a increased visibility to conservation model for regional planning efforts and to pursue and leverage throughout the entire Big Darby funding sources. In addition, the Watershed and the State of Ohio. Accord should establish an Open Working together has increased Space Advisory Council to guide benefits for all communities in and coordinate conservation efforts. the watershed. The jurisdictions Programs should be established to of the Accord and their partners allow for land acquisition, density have raised the bar in a spirited transfers, nutrient reduction on commitment to protect the farmland, backyard conservation, Big Darby Watershed for and outreach to landowners. generations to come.

B I G D A R B Y A C C O R D E X E C U T I V E S U M M A R Y / vii Proposed General Land Use Map

viii / E X E C U T I V E S U M M A R Y B I G D A R B Y A C C O R D 1.0 Introduction

1.1 Formation of the Accord

It has been well documented that the Big Darby Watershed is one of the most biologically diverse aquatic systems in the Midwest and is among the top warm freshwater habitats in the nation. The Big Darby Watershed is home to 38 state and federally listed aquatic species. The sustainability of the Big and Little Darby Creeks is of critical importance so that they continue to be healthy, biologically diverse, and a recreational treasure for current and future generations.

The Big Darby Watershed also represents the largest undeveloped Big Darby Creek area in Franklin County. With the Source: The Nature Conservancy/Anthony Sasson continued growth of Central Ohio, the watershed has experienced understanding of the importance of Watershed in Franklin County. increased development pressures in the watershed, the quality of the The plan recognizes that while “the recent years. Due to the unique waterways and the vision of each City of Columbus will ultimately nature of the Big and Little Darby jurisdiction, and have served as a provide centralized service within a Creeks, any development within foundation of the Big Darby Accord portion of it, no service whatsoever their watersheds must be carefully planning effort. shall be provided within the ESDA planned and managed. until the following conditions are

In addition to the comprehensive met for the area to be served: In July 2004, elected officials from planning activities, two recent • Riparian buffer restrictions jurisdictions that comprise the Big initiatives have brought together are in place; Darby Watershed in Franklin representatives of multiple • Comprehensive stormwater County gathered to discuss the jurisdictions and interests to management planning has occurred; importance of protecting the address watershed issues: the • Conservation development watershed and the need for a ESDA External Advisory Group restrictions are in place which involve common vision for future and the Hellbranch Watershed the concept of clustering development. Jurisdictions Forum. The Big Darby Accord Plan development to preserve tracts of involved included Brown, Prairie, is the culmination of these efforts. open space, including farmland; and Pleasant, Norwich and Washington • Adequate public facilities, including Townships; the Cities of Columbus ESDA External Advisory Group roadways, exist or are planned to Hilliard, and Grove City; the The EPA‐approved Columbus support any proposed development.” Village of Harrisburg; and Franklin Metropolitan Facilities Plan Update County. (November 3, 2000) establishes a

goal “to protect critical water The historic meeting of Big Darby Section Outline PG resources, especially in the Darby jurisdictions followed years of 1.1 Formation of the Accord 1-1 Watershed.” This plan designates studies and planning activities by 1.2 Plan Principles 1-4 an Environmentally Sensitive each jurisdiction and various other 1.3 Planning Process 1-6 Development Area (ESDA) that organizations. These efforts have 1.4 Report Format 1-7 includes most of the Big Darby contributed to a common

B I G D A R B Y A C C O R D C H A P T E R 1 . 0 ― I N T R O D U C T I O N / 1-1 The Hellbranch Watershed Forum Planning Area corridors within the planning The Hellbranch Watershed Forum The Big Darby Watershed covers area include Big Darby Creek, was created by a cooperative 555 square miles of central Ohio Little Darby Creek, Hellbranch agreement signed May 22, 2002 by just west of the Columbus Run, Clover Groff and Hamilton elected officials of Franklin County; metropolitan area (see Figure 1.1). Ditches (herein referred to as Runs). the cities of Columbus, Hilliard, Big Darby Creek originates in and Grove City; and Brown, Logan County and flows more than The Big Darby Accord planning Norwich, Pleasant, and Prairie 80 miles before joining the Scioto area encompasses the portion of the townships. The Forum was River near Circleville, Ohio. Land Big Darby watershed within organized to collaboratively use is predominately row crop Franklin County and includes the develop consistent stormwater agricultural, except for the area associated with the City of policies and regulations, develop a watershedʹs suburbanizing eastern Columbus’ adopted Hellbranch pilot restoration project, and edge along the border of Madison Run Watershed Protection Overlay cooperate in and support a and Franklin Counties, and in and the established Environ‐ watershed plan for responsible Union County. mentally Sensitive Development development and stewardship of Area (ESDA). The limits of the the Hellbranch Watershed. Work The Big Darby Accord planning planning area are primarily defined completed as part of the Hellbranch area (shown in Figure 1.3) is 84 by the US Geological Survey Watershed Forum effort has been square miles in size, or about 56,000 hydrologic unit code boundary for incorporated into the Big Darby acres, and represents about 15% of the Big Darby Creek Watershed in Accord effort. the total watershed. Major stream Franklin County. Those limits have been refined and extended by using the 2‐foot contour interval mapping published by the Franklin County Auditor. It is recognized that some sites located at the eastern edge of the planning area may not actually be part of the Big Darby watershed. It is not the intent of the Accord that the plan’s provisions apply to sites outside of natural drainage area of the Big Darby Watershed. This will require consideration on a site‐by‐site basis during the Big Darby implementation process. Watershed Aside from the County which includes all jurisdictions, the largest jurisdiction by land area within the planning area is Pleasant Township Planning with 24,000 acres, or 45% of the Area planning area. Grove City, although part of the Accord, does not have any land within the actual planning area boundary. Figure 1.2 shows the acreage for each jurisdiction based on GIS mapping.

Figure 1.1 Planning Area (orange) within Big Darby Creek Watershed (blue) Source: EDAW

1-2 / C H A P T E R 1 . 0 ― I N T R O D U C T I O N B I G D A R B Y A C C O R D % of Jurisdiction Acres Planning Area Brown 13,840 25.67 Norwich 1,025 1.90 Prairie 10,530 19.53 Pleasant 24,018 44.54 Washington 8.7 0.02 Columbus 3,102 5.75 Hilliard 1,209 2.24 Harrisburg 82 0.15

Figure 1.2 Acres Per Jurisdiction within Planning Area Note: Acreages are estimates.

Figure 1.3 Accord Jurisdictions and Planning Area

B I G D A R B Y A C C O R D C H A P T E R 1 . 0 ― I N T R O D U C T I O N / 1-3 sensitive areas. This approach Mission Statement promotes a responsible growth The Big Darby Accord consists of local governments within the Franklin pattern as recommended in the County area of the Big Darby Creek Watershed. The mission of the Big mission statement. Darby Accord is to cooperatively develop a multi-jurisdictional plan and accompanying preservation and growth strategies, capable of A general land use plan that implementation, oversight, and enforcement, which are designed to: recognizes existing sewer and wastewater treatment capacities, • Preserve, protect and improve, when possible, the Big Darby Watershed's while taking into account the unique ecosystem by utilizing the best available science, engineering and rights accorded watershed land use planning practices; landowners under current zoning • Promote responsible growth by taking measures to provide for adequate The plan will work within the public services and facilities and promote a full spectrum of housing limits of existing sewage choice, as well as adequate educational, recreational, and civic conveyance system and treatment opportunities, for citizens of each jurisdiction and for Central Ohio; capacities. At the same time, the plan will recognize zoning and • Create a partnership that recognizes the identity, aspirations, rights, and development rights that are duties of all jurisdictions and that develops methods of cooperation currently in place. The plan will among the partners through means which include the cooperative identify practical and equitable utilization of public services and facilities; and mechanisms of preserving these • Capitalize on the results of other efforts by considering local rights while striving to protect comprehensive plans, as well as the work of the Environmentally water quality by focusing density in Sensitive Development Area External Advisory Group, the Hellbranch key locations. Through this Watershed Forum, the 21st Century Growth Policy Team, and other local approach, the plan will seek a planning and zoning efforts, in the development of the plan. balance on both a regional and project‐specific basis where appropriate.

1.2 Big Darby Accord Plan green infrastructure includes Growth areas will be served by Principles floodplains, wetlands, groundwater adequate public facilities, and surface flow exchange areas, particularly central sewer The Accord has developed a set of special habitat areas, wooded areas, Central sewer service is planned for Plan Principles that has guided the and areas with groundwater identified growth areas including development of the Plan. The pollution potential. These elements the town center and existing principles have been instrumental contribute to the Darbyʹs unique contract service areas pending in achieving consensus among the ecosystem and should be protected available capacity. Central sewer Accord jurisdictions and have and preserved according to the service is not planned, or directly shaped the land use map mission statement, Accord anticipated for, a majority of the and planning process. As the recommendations, and regulatory planning area, including areas Accord moves forward to requirements, such as Ohio EPA’s associated with lower density implement the Plan, the Plan (OEPA) 208 plan. conservation development. Non‐ Principles will provide direction for centralized services would be decision making to local officials A general land use plan that subject to standards and inspection and to the public to ensure that balances environmental protection programs to ensure the systems are actions, both individually and and responsible growth functioning properly. Such a collectively, are achieving the Development is managed and program should be consistent with Mission of the Accord. focused in a sustainable town Accord recommendations and center and a range of conservation‐ regulatory requirements, such as Protection of environmentally style development patterns, which Ohio EPAʹs 208 plan. sensitive areas will create opportunities for open The general land use plan protects space preservation. The land use environmentally sensitive areas in a pattern offers a mix of uses, green infrastructure of maximizes access to infrastructure, approximately 20,000 acres. The and guides development to less

1-4 / C H A P T E R 1 . 0 ― I N T R O D U C T I O N B I G D A R B Y A C C O R D A development policy that Development without the established to help provide provides for mechanisms to condition of annexation community resources and acquire environmentally The City of Columbus is offering amenities and to initiate joint sensitive areas the limited extension of water and projects in the planning area, Development of policies and sewer services without the including open space. The general procedures that link new condition of annexation. As part of criteria may include, among other development to the provision of the Accord process, the City of things, establishing an amount of green space within the Columbus is identifying conditions millage to be collected by a environmentally sensitive areas of that must be met to qualify for Community Authority and the the land use plan, both regionally utility extensions into manner in which the proceeds and within the same site, is unincorporated areas. This will would be used. encouraged. These green spaces require consideration of existing would provide permanent utility contracts, design and cost Water quality, biological integrity, protection of the environmentally implications, capacity, provision of and adaptive management sensitive resources. a full range of housing options, This plan relies on the principle of revenue sharing and compliance adaptive management, an ongoing A memorandum of understanding with Accord provisions. process. This includes prediction, (MOU) among Accord members to monitoring, inspection, implement the agreed upon plan Mechanisms for cooperative enforcement, and ongoing planning The MOU represents a commitment revenue sharing among Accord to continue to maintain and pursue to continue to implement the plan members aggressive Ohio EPA water quality and work together to leverage Through the creation of joint goals that will improve the water resources. The MOU encourages economic development districts quality and biological integrity of consistency and compliance across (JEDD), cooperative economic the Big Darby Watershed. Pursuit political boundaries. As a primary development agreements (CEDA), of this objective is balanced with step in a long‐term implementation and/or community authorities, the understanding that, while process, the MOU underscores the Accord members can structure Accord provisions can apply to the importance of adaptive specific agreements to allow entire watershed, they can only management techniques to monitor revenue sharing across political address the Franklin County plan implementation. boundaries as development comes portion of the overall watershed. on line. Cooperative agreements and new revenues can be

Source: EDAW

B I G D A R B Y A C C O R D C H A P T E R 1 . 0 ― I N T R O D U C T I O N / 1-5 Figure 1.4 Big Darby Accord Planning Process Diagram

1.3 Planning Process Phase 2 jurisdictions. Members included • Best management practices analyses representatives from the Ohio The Big Darby Accord planning • Tools and programs for conservation Department of Natural Resources; process was initiated in April 2005. and development Ohio Environmental Protection The ten jurisdictions that form the • Revenue generation and agreements Agency, Metro Parks, Darby Creek Accord have guided the planning • Draft Plan development Association; The Nature process with the help of a • Final Plan Conservancy; Franklin Soil and subcommittee, referred to as the Water Conservation District; Group of Four (G4). The G4 The planning process has included Columbus and Franklin County representatives were ambassadors a variety of opportunities for public Housing Trust Corporation; of the process, guiding the feedback including stakeholder Building Industry Association of consultant team, communicating interviews, small focus groups, four Central Ohio; and United Way of with the public, and conveying public meetings, a project website Central Ohio. feedback from all ten jurisdictions (http://www.franklincountyohio.go into the process. v/BigDarbyAccord), email Combined, these efforts have notifications, press releases, a reached residents and interested Figure 1.4 represents the overall hotline number, and mailings. In citizens and generated healthy planning process from initiation to addition, events such as panel dialogue around key plan issues. plan completion. discussions have been sponsored This input has directly shaped the by individual jurisdictions and Phase 1 other organizations to provide • Data collection, outreach and education and outreach to stakeholder interviews interested citizens on planning • Inventory and analysis of existing topics that relate to the future of the conditions, plans, and policies watershed. Interest in the Accord • Land use scenario development and process has been strong with good hydrological model application attendance at public events. • Development of preliminary land use plan map In addition, a stakeholder group comprised of representatives from various agencies met consistently over the course of the planning effort to provide guidance to the planning team and Accord June 2005 Accord Public Meeting Source: EDAW

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This document is set up in five sections and an appendix, briefly described as follows:

Section 1: Introduction – provides an overview of how the planning process was initiated, describes the Accord Mission and Principles and the plan process.

Section 2: Plan Framework – describes the factors instrumental to the development of the land use plan including natural resources, Big Darby Creek Tributary available infrastructure and Source: The Nature Conservancy/Anthony Sasson current policies.

Section 3: Land Use – identifies the plan and guided policies and the adoption of the Big Darby conservation and development standards that are described in the Accord Plan, each jurisdiction will strategy for the planning area. following sections of this plan. The then need to review their zoning

Accord process is an example of a code to determine how to Section 4: Policies – sets forth successful regional collaborative implement the land use plan. This policies that will be needed in order planning process that should be too will involve a process of public to meet the Mission and implement considered throughout the Darby discussion and endorsement by the the plan related to open space, Watershed. locally elected officials. development, water quality, and

coordination. The Big Darby Accord Plan is The Big Darby Accord Plan will be intended to serve as a implemented over the next twenty Section 5: Implementation – multi‐jurisdictional guide for to thirty years; therefore, the plan identifies a series of programs and development and conservation. has built‐in flexibility to adapt to revenue sources for plan changing community needs and implementation. It is the goal of the Accord that each new technologies. jurisdiction work towards adoption Appendix: The appendix is and implementation of the plan and Implementation efforts among the structured to provide background its provisions. It is recognized that Accord jurisdictions, partner information that supports the plan application of the Plan at the local agencies and organizations, and recommendations. Appendices A level will require flexibility to allow property owners are already through F provide additional for varying and unanticipated underway. The success of this information related to water circumstances. Plan planning effort will lie in the ability quality, funding, planning data implementation will also require of the Accord and others to work sources, development review, monitoring and periodic updates to together in the pursuit of the considerations for a stormwater ensure currency. Mission. Over time this plan will utility and draft recommendations need to be updated to adapt to new related to alternative community Adoption of this Plan at the local technologies and changing land wastewater systems. level will require a process that uses to ensure water quality goals meets each jurisdiction’s are being met and programs and requirements for policy adoption. It policies are relevant. This planning is anticipated that adoption will effort should serve as a model for include additional public meetings, cooperative planning in the and input and endorsement by the watershed. locally elected officials. Following

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1-8 / C H A P T E R 1 . 0 ― I N T R O D U C T I O N B I G D A R B Y A C C O R D 2.0 Plan Framework

The Big Darby Accord Plan has Darby Watershed. These drivers County Zoning Resolution (though been developed to provide a have influenced land use and Harrisburg is in the process of proactive approach to managing policy recommendations and creating their own code). development and ensuring the represent both opportunities and protection and improvement of constraints. The drivers have Population Growth water quality and aquatic habitat largely shaped the Plan and will It is worth emphasizing that the in the Big Darby Creek continue to be factors as plan current land use and zoning watershed. The Plan provides implementation is initiated. policies allow for a significant guidance for how and which land amount of future development to should be developed, preserved, The drivers, described further in occur within the planning area. and protected. The Plan, similar the following sections, provide a Additional households will bring to a comprehensive plan, solid framework for the an increase in population. A provides land use and policy formation of a conservation comparison among several reports guidance for changes in land use strategy, the general land use about population growth reveals a over time. plan and implementation consistent belief that the central strategies. Drivers include: Ohio region will continue to grow As discussed in the Darby Accord 1. By‐Right Zoning – the allowable over the next twenty to thirty years. Mission Statement, the Big Darby level of development established by The exact rate of growth is difficult Accord Plan seeks to balance current zoning to determine and often varies development with protection of 2. Infrastructure among agencies and experts the Big Darby Watershed. In 3. Environmental Sensitivity because population growth is developing the general land use Analysis dependent on many factors. plan, a significant amount of 4. Water Quality and Biology However, it is reasonable to expect existing conditions data was that a certain amount of growth is reviewed and additional analyses 2.1 By-Right Zoning inevitable. The economies of the were completed. Information central Ohio area continue to reviewed included: Zoning codes and regulations expand by attracting more jobs and • Natural resources including dictate permitted land uses and the people to fill those positions. This streams, soils, floodplain, wetlands, maximum amount of development trend results in an increased vegetation, hydrology and other that can occur within a given area. demand for housing and services sensitive resources As a result, zoning has one of the including transportation, schools, • Current policies and plans largest impacts on existing land use community facilities, and other including land use, zoning, and patterns. Zoning regulations within basic services. comprehensive plans the planning area vary by • Water quality trends and impacts jurisdiction and are therefore The most widely referenced source associated with existing and difficult to summarize in a for population information is the proposed land use changes comparative way. For example, low US Census that occurs every ten • Physical conditions such as existing density residential development years. Many other studies use US and planned infrastructure (e.g., means one thing to the City of Census data as a baseline to roads, central sewer systems) Columbus and something else to an • Current local and state regulations unincorporated area of Franklin County. Today, the Cities of Review and analysis of available Hilliard, Columbus, and Grove City Section Outline PG information resulted in the as well as Prairie and Washington 2.1 By-Right Zoning 2-1 identification of “plan drivers,” Townships administer their own 2.2. Infrastructure or significant factors that affect zoning regulations. The remaining Considerations 2-4 the amount of development that jurisdictions, Brown, Norwich, 2.3 Sensitivity Analysis 2-11 the area could achieve and still Pleasant, and the Village of 2.4 Water Quality provide protection for the Big Harrisburg, follow the Franklin and Biology 2-14

B I G D A R B Y A C C O R D C H A P T E R 2 . 0 ― P L A N F R A M E W O R K / 2-1 Median * Owner Occupied Year Housing Median Value Housing Units Structure % % Jurisdiction Built 1990 2000 Change 1990 2000 Change Brown 1977 $116,600 $193,900 66.3% 620 709 14.4% formulate population projections. Norwich 1987 $88,800 $158,000 77.9% 1,598 1,450 -9.3% Ohio County Indicators and Ohio Prairie 1966 $63,400 $91,800 44.8% 6,629 6,954 4.9% County Profiles, prepared by the Pleasant 1974 $92,600 $135,900 46.8% 2,222 2,507 12.8% Office of Strategic Research, Ohio Washington 1981 $162,700 $109,200 -32.9% 736 464 -37.0% Grove City 1977 $74,900 $119,800 59.9% 7,675 10,712 39.6% Department of Development, Hilliard 1991 $72,600 $157,600 117.1% 4,556 8,957 96.6% project population for each county Harrisburg 1940 $62,000 $92,000 48.4% 137 140 2.2% in Ohio through 2030. Population Columbus 1970 $65,300 $101,400 55.3% 277,744 323,236 16.4% Franklin County - $73,300 $116,200 58.5% 405,418 471,016 16.2% forecasts by the Office of Strategic Ohio - $62,900 $103,700 64.9% 4,371,945 4,783,051 9.4% Research are based on 2000 Census data and are provided in five year Figure 2.2 Housing Characteristics increments. Projections are based Sources: US Census, 1990 and 2000. These numbers reflect entire jurisdictions and not just the planning on assumptions about trends in fertility, mortality, and net Housing initiatives in Hilliard have migration. Within Ohio, an increasing trend dramatically curtailed the shows that land in active residential growth rate. According to the Office of Strategic agricultural use is declining and the Jurisdictions marking decreases in Research, Franklin County is amount of agricultural land that is the number of housing units, most projected to continue to grow to a non‐cultivated is increasing. Recent likely due to loss of land through total population of 1,326,180 in the development patterns within the annexation, include Washington year 2030 (Figure 2.1). This planning area reinforce this trend and Norwich Townships. represents a 20% increase over year as agricultural lands are being 2000 population levels. Some of the converted to other uses, primarily Housing units are rising in value projected growth will occur within low‐density housing (Growth and and continue to exceed the owner‐ the planning area and local zoning Change at the Rural‐Urban occupied median value of homes and comprehensive plans in the Interface, 2003). The trend for large‐ around the state (Figure 2.2). With planning area have policies in place lot residential developments is the exception of Washington to allow for development. occurring throughout the planning Township, all jurisdictions area as subdivision practices experienced an increase of housing produce 5 to 20 acre lots along rural values between 46 and 117%. roads. Existing zoning regulations Housing values show that homes have helped define the existing located in the northern part of the landscape and promoted a rural planning area, specifically the City pattern of development that is of Hilliard, Brown, and Norwich Office of Strategic highly consumptive of land. Townships, maintain the highest Research owner occupied median home Projected % Change According to the US Census, values within the planning area. Year Population from 2000 Franklin County is growing faster Homes in this area experienced the 2000 1,068,978 0% than the state in housing units. Both most increase in value between 2005 1,112,880 0.0% Franklin County and the City of 1990 and 2000. 2010 1,155,910 4.1% Columbus experienced a 16% 2015 1,195,310 8.1% increase in housing units from 1990 Future Level of Development 2020 1,238,250 11.8% to 2000, well above the 9.4% at the As future land uses were 2025 1,281,760 15.8% state level. Annexation policies considered, it became 2030 1,326,180 19.9% have contributed to increases in increasingly important to identify Figure 2.1 Franklin County housing units for incorporated an overall level of growth that Population Projections areas and a loss of housing in would be appropriate for the Sources: Ohio Office of Strategic Research, 2003. unincorporated areas. Housing Franklin County portion of the units in the City of Hilliard almost Big Darby Watershed. Residents doubled from 1990 to 2000, expressed a desire to retain the marking an explosive growth rural character of the area and to period for the City and increased encourage a higher standard of demand for services to meet the development that would protect influx of residents. Recent water quality.

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Figure 2.3 Density Map

B I G D A R B Y A C C O R D C H A P T E R 2 . 0 ― P L A N F R A M E W O R K / 2-3 Accord jurisdictions have additional growth of municipal boundary but relies on endorsed the concept of allowing approximately 20,000 dwelling Columbus for wastewater for a similar level of overall units, or 51,000 additional people. treatment. development within the planning Overall, when combined, the area that is currently allowed long‐term build based on the by‐ Within the Accord planning area, under the existing zoning. right concept is approximately the 208 Plan also identifies an area Referred to as “By‐Right Zoning,” 100,000 people. Development surrounding Lake Darby Estates, this concept recognizes the potential will be constrained by immediately west of and zoning densities that are in place environmental and infrastructure overlapping with a portion of the today as a baseline for overall considerations, including the town center, as a sub‐Regional future development. Current ability to properly permit and Facilities Planning Area and zoning policies related to density, regulate non‐centralized sewer designates Ohio American Water as shown in Figure 2.3, favor a low systems. New standards, policies, the DMA for that area. Ohio density development pattern and programs identified American Water operates a distributed across the planning elsewhere in this plan will be wastewater treatment plant that is area. Pockets of higher density needed to properly manage new exclusive to the designated sub‐ are located along the eastern edge development in a way that regional area and that discharges and along West Broad Street. enhances quality of life for people directly to Big Darby Creek. Further analysis reveals that if the and the environment. current policies were carried, Another DMA within the Accord approximately 20,000 dwelling 2.2 Infrastructure planning area is the Franklin units could be developed within Considerations County Sanitary Engineer’s the planning area in a dispersed Department, which operates several pattern; the Accord Plan proposes Access to adequate facilities is an smaller wastewater treatment a similar level of development, essential ingredient in identifying facilities scattered throughout the but in a pattern that is more appropriate growth areas. Two planning area, including a new 0.3 manageable, sustainable, and major factors have surfaced as Million Gallon per Day (MGD) environmentally sensitive. primary infrastructure Wastewater Treatment Plant near considerations: sewer capacity the unincorporated Village of The proposed plan, described in and service area, and existing and Darbydale. The facility became Section 3.0, focuses density in a planned roadway infrastructure. operational in the summer of July areas along the eastern edge of 2005 and serves the unincorporated the planning area adjacent to the Sewer Service Village of Darbydale, the Oak Hills Cities of Hilliard and Columbus The Accord planning area lies Mobile Home Park (MHP), the and suggests a higher density within the City of Columbus’ Community Gardens MHP, the “Town Center” between I‐70 and Regional Facility Planning Area Pleasant Acres MHP, and the US 40 (West Broad Street). The (RFPA), as designated by the Ohio Darbydale Elementary School. In Town Center location is based EPA’s (OEPA) 208 Plan, which also addition, the Franklin County on the availability of central identifies the City as the Designated Sanitary Engineer will serve the sewer service, existing road Management Agency (DMA) Timberlake subdivision through the infrastructure, and reduced responsible for providing sewer Darbydale WWTP, thereby concentrations of service within this area. All allowing the previously operating environmentally sensitive sewages collected by the City of Timberlake WWTP to be resources. Columbus within this area would eliminated. The service area for the be conveyed to and treated at the Darbydale WWTP is set forth in the Based on analysis, it is estimated Southerly and Jackson Pike Ohio EPA Director’s Final Findings there are 19,000 existing housing wastewater treatment plants, which and Orders (DFFO), which was units within the planning area discharge directly to the Scioto issued to the County today. Based on a conservative River. As a separate incorporated Commissioners for sewage assumption of 2.58 people per area, the City of Hilliard has a treatment problems in the household, this equates to an sewer service contract with the City Darbydale area. Only those specific existing population of of Columbus. Under the terms of properties enumerated within the approximately 49,000. As stated that contract, Hilliard owns and Orders will be served, expanded to above, current policies allow for maintains sewer lines within their include the Timberlake subdivision.

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The Village of Harrisburg has groundwater depth, and the type Central sewer service would also be approached Franklin County and density of the development provided in a manner consistent regarding the possibility of sewage all have an impact on the form of with the general land use plan to service through the Darbydale sewage treatment that is the Hilliard Growth area and LEED WWTP. The County Sanitary appropriate and possible. area. Analysis performed for the Engineer has noted that the WWTP Roberts Millikin sanitary sub‐trunk has sufficient capacity to serve the Connection to an Existing Central sewer shows an ability to provide existing village but, in doing so, Sewer System sewer service 2,000 equivalent would reduce the capacity of the The City of Columbus owns and dwelling units in the Hilliard plant to service other areas. It is maintains the Big Run sanitary growth area. This system could anticipated that the County will trunk sewer, which is located also provide capacity for agree to provide service to the along Broad Street and terminates approximately 1,400 equivalent Village and would coordinate with near the eastern boundary of the dwelling units in what has been the Ohio EPA to ensure Accord planning area. The City referred to as the LEED area east of conformance with the provisions of also owns the Roberts‐Millikin Alton and Darby Creek Road and the 208 Plan regarding the sanitary sub‐trunk sewer located south of Roberts. expanded service area. along Roberts Road which also terminates near the eastern Development of Community‐based Under the 208 Plan, neither Ohio boundary of the planning area. Alternative Sewage Treatment American Water nor the County Both of these sewers are shown Systems Sanitary Engineer is permitted to on Figure 2.4. For areas beyond that which provide sewer service beyond their would be served by a central presently designated service area The current capacity of each of sewer system, a separate option without the appropriate these sewer lines is a limiting for treatment is necessary. To authorization. Figure 2.4 shows the factor in the amount of avoid the future proliferation of sewer service areas for the planning development that can occur in HSTS within the planning area, area. these areas. If any additional efforts are underway to identify capacity in those systems community‐based applications In addition to the authorities becomes available in the future it that would offer a regional responsible for providing central will also affect the timeframe of approach to providing sewer sewer service within the Accord when development occurs. service. The intent of these planning area, the Franklin County applications would be to collect Board of Health is responsible for An initial capacity analysis of sewage from a regional area for the permitting and oversight of on‐ each of these sewer systems was transport to a location that is lot septic systems, also referred to conducted to determine the viable for lagoon and land as household sewage treatment extent to which additional application types of sewage systems (HSTS) or household development within the planning treatment, avoiding a direct sewage disposal systems. HSTS area could be accommodated discharge to any watercourse. applications are predominantly within the constraints of those Presently, separate technical and leach field or home aerator type systems. The City of Columbus regulatory committees formed of systems. In either case, there is has determined that the capacity local officials and experts in often a physical connection of the Big Run sanitary trunk alternative treatment systems are between that system and sewer would currently allow for convening to consider the details stormwater drainage, such a receiving 5,000 additional of the standards and regulatory roadside ditch or field tile. equivalent dwelling units from requirements related to these the Town Center portion of the types of systems. The goal is to Sewage Treatment Alternatives planning area. The Columbus identify a community‐based Development within the Accord sewer system may also have authority to own and operate planning area can be serviced additional capacity for some these systems, using an existing through various means of sewage areas closer to the existing DMA from the 208 Plan as that treatment. Despite the current system, currently annexed or authority. Appendix F includes zoning, the location of a zoned for development, in a draft recommendations put forth development site, physical manner consistent with the by the Alternative Wastewater limitations of soil types and Accord general land use plan. Treatment Technical Committee.

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Application of on‐lot systems Inevitably, there will continue to be some form of development within the Accord planning area that includes individual on‐lot systems. The committees referenced above are also looking at this issue and considering standards and regulations governing on‐lot systems. Presently, these systems are under the authority of the Franklin County Board of Health and would remain under that authority.

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Figure 2.4 Sewer Service Areas Map

B I G D A R B Y A C C O R D C H A P T E R 2 . 0 ― P L A N F R A M E W O R K / 2-7 Transportation For planning level assessments, This plan does not include a the 24‐hour average daily traffic detailed transportation analysis (ADT) relates to a service level as or modeling of traffic impacts. shown in Figure 2.6. However, a review of planned transportation projects is helpful Based on analysis of data, none of in understanding future impacts the current ADTs on the two‐lane related to new development. roadways approach the 10,000 vehicle threshold. Therefore, the The roadway system within the two‐lane roadway system in the Accord planning area is primarily planning area is basically composed of two‐lane rural operating at a “C” level of service roads. This is particularly the case or better overall. This is not to say for the roadway systems west of that there aren’t some capacity the Cosgray Road/Alton & Darby problems at individual Creek Road corridors. As intersections. As intersection annexations and developments capacity problems begin to occur, have progressed westward and the responsible public agencies reached the Cosgray Road/Alton have been adding turn lanes at & Darby Creek corridor, roadway intersections and installing traffic widening and intersection signals in some instances. A improvements have begun to take number of transportation place along Cosgray Road and improvement plans are identified Alton & Darby Creek Road – and on Figure 2.5 that were noted in along north‐south and east‐west the Franklin County roadways east of this corridor. Thoroughfare Plan, the 2006‐2009 Transportation Improvement A common approach to Plan (TIP), and the 2030 transportation planning applies a Transportation Plan. “planning level” assessment when relating 24‐hour traffic The 2006‐2009 TIP includes only volumes to the ability of a two projects relative to the roadway to properly planning area that relate to minor accommodate the traffic widening and safety demands. This assessment relates improvements to Scioto Darby traffic demands to level‐of‐ Creek Road – along with service. Level‐of‐service (LOS) is improvements at the intersection based on a grading system which of Scioto Darby Creek Road with ranges from “A”, or perfect Alton & Darby Creek Road. operation, to “F”, failing. An LOS “E” indicates that a facility is operating basically at capacity and the addition of more traffic will cause the facility to fail. When improvements are considered for the transportation system, the goal is to achieve an LOS “C” or “D” in the peak design hour through the 20‐year life of the facility.

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Figure 2.5 Transportation Map

B I G D A R B Y A C C O R D C H A P T E R 2 . 0 ― P L A N F R A M E W O R K / 2-9 Max ADT Max ADT Max ADT Type of Facility @ LOS “C” @ LOS “D” @ LOS “E” 2-lane Roadway2 10,000 10,000 to 15,0004 15,000 4-lane Roadway3 20,000 25,000 to 35,0004 33,000 to 41,000 4 6-lane Roadway3 30,000 35,000 to 45,0004 50,000+4

Figure 2.6 General Planning Level Average Daily Traffic LOS Thresholds *Assumes peak hour traffic is approximately 9% of daily traffic with approximately a 60/40 directional split. 2The threshold varies depending on the presence of a left turn lane at intersections or other access points. 3 Assumes necessary turn lanes at intersections. 4The threshold varies depending on the volume of cross-road traffic needing to access the facility.

There are numerous projects It should be noted that listed in the 2030 Transportation interchange upgrades are called Plan. Most of these projects relate for on I‐270 at Cemetery Road, to the Cosgray Road/Alton & Roberts Road, and Georgesville Darby Creek Road corridor and Road, and on I‐70 at Hilliard‐ areas to the east. Of significance Rome Road. These interchanges are the proposed extensions of are already over capacity and Alton & Darby Creek Road north severe congestion occurs. Of and south, the connection of particular significance to the Alton & Darby Creek Road with Accord planning area, the Cosgray Road, and a couple of Hilliard‐Rome Road interchange new roads related to the southern on I‐70 realizes excessive traffic extension of Elliott Road. demands since it is the only Improvements are called for at interchange between Big Darby the intersections of Walker Road Creek and I‐270. Significant with Roberts and Amity Roads, additional developments west of and safety improvements are the Alton & Darby Creek Road called for along Alkire Road and corridor will increase traffic Norton Road. demands on the east‐west feeder roads (e.g. Feder and Renner Roads) and on already overloaded Hilliard‐Rome Road.

A more detailed discussion of infrastructure policy considerations is included in Sections 4.0 and 5.0.

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Hydro-geologic Hydrologic Ecologic Groundwater and Surface Flow Exchange Wetlands Threatened and Endangered Species Soils Floodplains Land Cover (Woodlands) Groundwater Pollution Potential Stream Attainment Levels

Figure 2.7 Environmental Sensitivity Analysis Resources

2.3 Sensitivity Analysis Environmentally sensitive areas In isolation wooded areas may were identified using the following appear unimportant; however, this The process for developing an three step resource‐based analysis is oriented toward creating evaluation system to identify evaluation method: future land use scenarios of which environmentally sensitive areas in Step 1: GIS Data Layer Analysis wooded areas and tree cover are the planning area was a necessary Step 2: Qualitative Assignment considered valued components. first step in creating a land use Step 3: Merge and Join Additional analyses were plan. Existing landscape features, conducted to identify water quality both natural and man‐made Step 1: GIS Data Layer Analysis factors that relate to environmental provided a starting point to Hydro‐geologic, hydrologic, and sensitivity. It is important to note formulating future land use ecologic resources were evaluated that not all habitat and water scenarios and were considered as and in some cases further analyzed quality factors translate to the foundation for the land use for specific information. Identifying identifiable features on the alternatives developed during the areas that exhibit high and landscape such as a wetland or planning process. Because of their moderate degrees of ground and floodplain. For example, aquatic life complex qualities and their valued surface water flow exchange and use attainment ratings for the Big function in the watershed, groundwater pollution potential Darby, Little Darby, Clover Groff, environmentally sensitive areas are required a closer analysis of Hamilton and Hellbranch are considered suitable candidates for DRASTIC data from the Ohio identified and recognized, but are open space, parks, or other Department of Natural Resources not specifically listed as factors preserved lands. The Big Darby (ODNR). DRASTIC uses a because they are qualitative. Watershed is valued for its habitat numerical rating and weighting However, the environmental systems, water quality, and system that is combined with the sensitivity process does recognize ecology. Protecting these systems seven factors to calculate a ground the importance of protecting the and ensuring their sustainability water pollution potential index or aquatic environment through and improvement is a baseline relative measure of vulnerability to multiple avenues including the consideration for the environmental contamination. DRASTIC factors identification of floodplains and sensitivity analysis and an overall include: riparian setback zones and through goal of the Big Darby Accord Plan. D – depth to water the policy recommendations. R – depth to recharge The environmental sensitivity A – aquifer media FEMA published floodplains are evaluation process consulted a S – soil media present along major stream number of resources collected from T – Topography (% slope) corridors including Big Darby multiple sources including an I – Impact to Vadose zone media Creek, Little Darby Creek, extensive amount of geographic C – Conductivity to the aquifer Hellbranch Run, Clover Groff and information system (GIS) data. A the Hamilton Ditches (herein after list of the base GIS data that has Other analyses were conducted to referred to as Clover Groff and been compiled as part of this extract highly erodible soils and Hamilton Runs). To address stream planning effort is provided in the soils with hydric components. Land corridors without FEMA Appendix. To simplify and cover, particularly wooded areas floodplains, a calculated beltwidth organize an evaluation system, the greater than three acres were has been applied to provide an key resources shown in Figure 2.7 identified as key areas for habitat offset from the centerline of the were considered as part of the and potential linkages in a green stream. environmental sensitivity analysis. network that would contribute to overall ecosystems in place.

B I G D A R B Y A C C O R D C H A P T E R 2 . 0 ― P L A N F R A M E W O R K / 2-11 High Medium Low Category 1 Category 2 Category 3 Hydrogeologic areas. Development policies and High Degree of Flow Exchange H regulations for best management Moderate Degree of Flow Exchange M practices and non‐central High Groundwater Pollution Potential H sewer systems further address Highly Erodible Soils H hydric soils. Areas with Hydric Soils L

Hydrologic All high, medium, and low Wetlands H FEMA 100 Year floodplain Boundary H environmentally sensitive areas Beltwidth Calculated Buffer Zone H should be considered as having FEMA 500 Year floodplain Boundary L important values worthy of Ecologic preservation. The presence of Federal, State Endangered H environmental factors also State Threatened H correlates to potential problematic Species of Special Concern H impacts for development. Wooded Areas 3 Acres or Greater M

Wooded Areas 0.5 to 2.99 Acres L Step 3: Merge and Join The final step in the environmental Figure 2.8 Environmental Sensitivity Analysis Components and Categorization sensitivity analysis created a composite map identifying all high, Step 2: Qualitative Assignment Areas with a moderate degree of medium and low areas shown in The key resource data layers were flow exchange between ground and Figure 2.9. Due to the existing assigned a qualitative value of high, surface water were assigned a predominantly low density medium, or low, shown in Figure medium sensitivity. In addition, development pattern, it was 2.8. A qualitative assignment was wooded areas of three or more decided that existing development necessary to prioritize the acres were assigned a medium patterns should not be excluded environmentally sensitive areas in value to emphasize their from the environmental the planning area for their value in importance in providing habitat sensitivity process. Areas that are maintaining a healthy watershed areas and creating a network of already developed may be and to begin to recognize degrees of green corridors. suitable for mitigation techniques sensitivity as they relate to or other preservation efforts proposed future land uses. Those features assigned a low to enhance or protect identified environmentally sensitive value sensitive resources. A highly sensitive value is relate to Hydric soils, land within associated with resources that relate the 500 year floodplain (beyond the Overall, 32,351 acres of to protecting water quality, both 100 year floodplain boundary), and environmentally sensitive areas surface and groundwater, or critical wooded areas between one half and were identified, covering 60% of the habitat areas (threatened, three acres. Hydric soils compose a planning area. Of those resources endangered, or species of concern) significant amount of land within identified through this process, for plant and wildlife habitat the planning area and are a limiting about half are highly sensitive. The recognized by Federal or State factor for certain types of majority of those features in the agencies. Areas that exhibit a high development. Soil type becomes of high category are associated with degree of flow exchange or a high particular importance when dealing high potential for groundwater and groundwater pollution potential with alternative sewage treatment surface water flow exchange and due to hydro‐geologic or on‐lot septic systems and, high groundwater pollution characteristics were ranked high. therefore, should be addressed potential. When combined, the high Linear features such as floodplains through the site development and medium sensitive areas or beltwidths are also assigned a review and approval process. account for about 19,000 acres high value for their recognized Hydric soils are not well‐suited for within the planning area, or value in maintaining healthy septic systems because they 35% of the planning area. The waterways, providing habitat areas encumber the treatment process majority of resources within in streams and along water ways, and limit filtration of effluent. This the low category are attributed to and minimizing flood damage and process has identified hydric soils areas with hydric soils. personal property loss. to understand how they relate to other environmentally sensitive

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Figure 2.9 Environmental Sensitivity Map

A significant amount of land within the planning area, 7,399 acres, is already protected in a system of parks and easements, primarily Metro Parks along Big Darby Creek. Easements account for 145 acres held through Franklin Soil and Water Conservation District. Existing parks and protected lands provide an initial green network for the planning area and help provide protection to sensitive natural resources. For the purpose of this analysis, existing protected lands or open spaces includes park lands, easements, golf courses, and cemeteries.

Almost 22% or 7,000 acres, of the identified high, medium, and low sensitive areas are located within existing open space lands. This overlap is most apparent in the high category where over 5,000 acres of land is protected. Although this is commendable, more than 25,000 acres of sensitive areas remain unprotected, some of which have already been developed.

B I G D A R B Y A C C O R D C H A P T E R 2 . 0 ― P L A N F R A M E W O R K / 2-13 2.4 Water Quality and Biology

Generally speaking, Ohio measures When addressing the issue of the health of its streams by healthy streams within the Accord examining the number and types of planning area, evidence shows a fish and macroinvertebrates living decline in the biological diversity of within the water environment and the aquatic ecosystem of Big Darby sets specific standards for ensuring Creek and non‐attainment of streams are meeting the several key water quality requirements to sustain these life parameters within the Hellbranch forms. The biological condition of Run Watershed, which comprises streams is a direct indicator of the a significant portion of the impact of surrounding landscape planning area. influences. This section discusses Long-ear Sunfish goals and programs tied to the Prior investigations into the Source: Metro Parks/Mac Albin improvement of water quality and biological diversity of the Big aquatic life use attainment within Darby Watershed have considered The Ohio EPA has performed the various watercourses in the several indicators of stream health, extensive investigations and studies planning area. Watercourses, including specific fish species, related to the water quality including subwatershed boundaries mussel communities, and conditions to the Big Darby and other hydrological resources macroinvertebrates. The Watershed. These efforts are shown in Figure 2.10. composition of each of these culminated in the publication of the communities is an indicator of the Total Maximum Daily Load The term ‘healthy stream’ is used to health of a stream, and declining (TMDL) report for the watershed describe a watercourse that meets a populations and diversity of each (OEPA, 2006). The TMDL focuses certain level of aquatic life use can provide an indication of on specific pollutant conditions and attainment and includes a diversity declining water quality. The trends loadings in identifying the extent to of qualifications. The concept of in aquatic habitat are captured in which impairment existed stream health can be generally the compiled scores for the Index of throughout the watershed. The distilled into four basic parameters: Biological Integrity (IBI) for fish, Hellbranch Run Watershed, which chemical water quality, and the Invertebrate Community comprises approximately 46% of morphology, habitat quality, and Index (ICI) for macroinvertebrates, the Accord planning area, was riparian and watershed quality. throughout the watershed. Another identified within the TMDL as a These parameters are interrelated method of assessing stream quality significant source of Total and their combined effect is the Qualitative Habitat Suspended Solids (TSS) and influences the quality and diversity Evaluation Index (QHEI), which is nutrient pollutants to Big Darby of the biotic communities (fish and utilized to determine the relative Creek. macroinvertebrates) within the quality of the physical habitat stream. In addition, the overall provided by the stream. This health of a stream is a determining assessment evaluates the factor in the amount of pollution geomorphological condition of the the stream can assimilate without stream by looking at channel becoming a toxic environment for substrate, morphology, and riffle the biota within. structure, as well as assessing the associated riparian corridor and adjacent floodplain.

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Figure 2.10 Hydrological Resources Map

B I G D A R B Y A C C O R D C H A P T E R 2 . 0 ― P L A N F R A M E W O R K / 2-15 Description of Watercourse Impairment The Hellbranch Run Watershed has within the channel bottom due to a been identified as being impaired lack of velocity and energy to carry and fails to meet certain water that material. The processes quality criteria. The Hellbranch associated with channel Run Watershed is comprised of two degradation are a primary source of main tributary streams: Clover sediment loading in a stream Groff Run and Hamilton Run. system, as confirmed by findings of These tributary streams are in close the Ohio EPA’s TMDL related to proximity to the expanding the Hellbranch Run Watershed. suburban areas of western Columbus; however, there is still a Degradation of the physical habitat significant presence of agricultural and riparian areas along streams land use within these watershed within the Hellbranch Run areas. Both watercourses have been Watershed, coupled with sediment hydrologically modified in the past, and nutrient runoff from attributed to a ‘ditching’ process agricultural and urban land use that is commonly associated with practices within the watershed, has agricultural land use within the an observable negative effect on Clover Groff (ditching) State of Ohio. The ditching process fish and macroinvertebrate at Roberts Road includes a straightening, widening, communities. This effect is Source: The Nature Conservancy / and deepening of the stream apparent in the generally lower ICI Anthony Sasson channel to increase flow capacity and IBI scores assessed by the Ohio and facilitate the use of field tile to EPA within Clover Groff Run, turbidity and smothering of drain the adjoining farm fields. In Hamilton Run, and the upper the channel bottom due to addition, the wooded riparian Hellbranch. The scores show a sedimentation within the channel corridor along these tributary general trend of improvement as (Discussions with Dr. Tom Watters, streams is degraded by land use the watercourses move OSU). activities that encroach upon the downstream towards the channels. Physical degradation of confluence with Hellbranch Run Aquatic Life Use Attainment Clover Groff and Hamilton Runs is and Big Darby Creek, where there Based upon the findings of the reflected in the generally low is a wider, more intact riparian Biological and Water Quality Study of QHEI scores assessed by the Ohio buffer and less channel the Big Darby Creek Watershed, EPA for the greater portion of these modification. 2001/2002 (OEPA, 2004), the Ohio streams, especially within the EPA has placed aquatic life use headwater areas. ICI and IBI scores calculated for the designations upon various portion of Big Darby Creek within watercourses within the Accord One consequence of the ditching the planning area indicated that the planning area. Furthermore, process is a channel loses the majority of the stream is meeting a through the TMDL process, the functional components that category of Exceptional Warmwater Ohio EPA has identified portions of contribute to aquatic habitat. Habitat (EWH). There is those watercourses that are in Furthermore, a channel that is information suggesting a attainment, partial attainment, or capable of conveying larger storm downward trend in QHEI scores non‐attainment of that use events is also subject to degradation for portions of the middle Big designation. Each category of use through channel bank erosion and Darby Creek and that the diversity attainment that pertains to ‘downcutting’, a process that only and overall population of mussel watercourses within the planning advances the ditching process by species is declining (Darby Creek area is described below lowering the channel gradient and Watershed Inventory, 2005). (TMDL, 2006). Figure 2.11 expanding the width of the Findings associated with the illustrates water quality issues in channel. Conversely, an over‐wide declining mussel communities the planning area. channel can be subject to suggest that this decline is possibly aggradation as sediments conveyed attributed to a decline in fish in stormwater runoff are deposited population and increasing water

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Figure 2.11 Water Quality Map

B I G D A R B Y A C C O R D C H A P T E R 2 . 0 ― P L A N F R A M E W O R K / 2-17 Level of Use Attainment Stream Name Aquatic Like Use Designation Full Partial Non Hellbranch Run Watershed Clover Groff Run MWH – upstream of Roberts Road X

WWH – downstream of Roberts Road to X the confluence Hamilton Run MWH – upstream of Widener Road X

WWH – downstream of Widener Road to X the confluence Hellbranch Run WWH – upstream of Beatty Road X

EWH – downstream of Beatty Road to the X confluence Big Darby Creek Watershed1 Main Stem2 EWH Upstream of Fitzgerald Run (RM 45.0) Downstream of

RM 45.0 Smith Run EWH X

Figure 2.12 Summary of Aquatic Life Use Designation and Attainment 1 Watercourses within the Big Darby Accord that are directly tributary to Big Darby Creek 2 Only the portion that discharges though Franklin County Source: OEPA TMDL, 2006; Big Darby Watershed Inventory, 2005

Warmwater Habitat (WWH): An Exceptional Warmwater Habitat There are several small tributary aquatic life use designation that is (EWH): An aquatic life use streams within the planning area characterized by the “typical” designation that is reserved for that are directly tributary to Big warmwater assemblage of aquatic waters that support “unusual and Darby Creek. The Ohio EPA, in organisms for Ohio’s rivers and exceptional” assemblages of aquatic their assessment of the Big Darby streams. This use represents the organisms that are characterized by Watershed has not provided an principal restoration target for the a high diversity of species, aquatic life use designation for majority of water resource particularly those that highly those watercourses, except for management efforts in Ohio. intolerant and/or rare, threatened Smith Run, and no attempt is made endangered or special status (e.g., here to provide an assessment of Modified Warmwater Habitat declining species). This designation the habitat conditions associated (MWH): An aquatic life use represents a protection goal for with those channels. Each has only designation that applies to rivers water resource management efforts a small watershed area in and streams that have been dealing with Ohio’s best water comparison to those that are subjected to extensive, maintained, resources. identified in Figure 2.12. and essentially permanent Furthermore, Little Darby Creek is hydromodification such that the Figure 2.12 provides a list of the not separately included in this biocriteria for the WWH use is non‐ various major watercourses studied assessment due to the fact that only attainable, and where the activities within the planning area, the a small portion of that watershed is have been sanctioned and designated life use attainment for within the Accord planning area. permitted by State or Federal law. each, and the finding pertaining to In these watercourse, the attainment (Big Darby Watershed representative aquatic assemblages Inventory, 2005/TMDL, 2006). are generally composed of species which are tolerant to low dissolved oxygen, silt, nutrient enrichment, and poor habitat quality.

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Impairment Summary A key driver of the Accord Plan is 3. Protecting larger contiguous The aquatic life use designations to achieve the aquatic life use forested areas. and the extent to which they are designation for each watercourse, 4. Implementing conservation development attained play a significant role in upgrading streams designated as with a 50% open space requirement. determining where changing land MWH to WWH where practicable. uses and restoration opportunities To achieve that, it is believed that Next, hydrological modeling can have the most significant stream restoration activities within provided a detailed analysis of the positive impact on water quality. the Hellbranch Run Watershed, impact of land use scenarios on the Significant impairment has been particularly along Clover Groff Run pollutants identified by the TMDL documented in the upper portion and Hamilton Run will be needed. as being factors in water quality of the Hellbranch Run Watershed, Sustainment of the EWH impairments within the planning associated with both the Hamilton designation for the main stem of area. The purpose of the analysis and Clover Groff Runs. the Big Darby Creek is also a goal was to determine how urbanizing of water quality initiatives within land uses affect the pollutant Conservation‐related land uses can the planning area. For this reason, loadings to the receiving streams have the most beneficial impact on attention must be paid to the and to better understand the impaired streams. Examples of smaller watercourses that are benefits of conservation land use these practices and their practical directly tributary to Big Darby practices. Efforts related to the benefits to water quality are Creek in the western portion of the hydrological modeling process are described below. planning area. described in the Appendix. 1. Preserving existing agricultural lands in perpetual conservation areas or Water Quality Goals The last step to establishing and easements for conversion to native Establishing and maintaining achieving healthy streams involved grass and woodlands can reduce the healthy streams required the investigating the use of stormwater amount of sediments and nutrients identification of a land use scenario BMPs related to land use conditions commonly associated with that over time would help address and established water quality stormwater runoff from that land use. issues of non‐attainment of aquatic targets within the TMDL. Each 2. Preservation and enhancement of life use designations within the BMP has unique benefits and riparian stream corridors provides an Hellbranch Run Watershed and drawbacks related to sustainment enriched habitat environment and preservation of areas of attainment and function. introducing vegetative cover would throughout the planning area. provide stream stability The planning area is comprised of characteristics. The first step in this process, the two distinct watersheds: 1) the 3. Conservation development practices environmental sensitivity analysis entire Hellbranch Run Watershed; that include open space set asides and identified areas that were to be and 2) the remaining areas to the stormwater Best Management protected from urbanization, which west and within Franklin County Practices (BMP), promoting constitute preferred areas for that are directly tributary to Big groundwater recharge, and providing conservation and possible Darby Creek. Within the TMDL structural measures for capturing restoration. Primary influences that document, the western areas are pollutants will help promote water determined the resulting general distributed amongst three separate quality improvements. land use plan related to water subwatershed areas, identified as 4. Implementing agriculture BMP’s can quality include: BDC 4, BDC 5, and BDC 6. mitigate the impacts of agricultural 1. Protecting floodplains and stream drainage (field tiles), sediments, and corridor protection zones throughout the Figure 2.13 identifies the pollutant nutrients commonly associated with planning area and preserving them as parameters and reductions that are agricultural lands. naturalized riparian corridors. stipulated in the TMDL report for 2. Avoiding areas of high the Hellbranch Run Watershed. groundwater/stream baseflow interaction Due to the fact that this watershed and pollution potential zones, as defined is a significant component of the by the Ohio Department of Natural Accord planning area and that only Resources (ODNR) DRASTIC mapping.

B I G D A R B Y A C C O R D C H A P T E R 2 . 0 ― P L A N F R A M E W O R K / 2-19 The initiative required Columbus, 1 Calculated Loadings (kilograms/year) who would ultimately provide the Pollutant Existing Target % Reduction to central sewer service, to convene an Meet Target External Advisory Group (EAG) Total Suspended Solids (TSS) 3,051,200 152,560 95 that would consider recommended Total Phosphorus (TP) 15,266 2,805 82 criteria for riparian buffers, stormwater management, Figure 2.13 Summary of Target Pollutant Load Reductions – conservation development and Hellbranch Run Watershed adequate public facilities. The EAG 1 All values are average annual values over the duration of the planning period, was comprised of representatives published in the TMDL; non-point source loadings only. from the municipal jurisdictions within the ESDA, along with other stakeholders, such as The Nature portions of the other TMDL‐ Hellbranch Overlay (Columbus) Conservancy, Darby Creek identified sub‐watersheds are In 2002, the City of Columbus Association, The Ohio State within the planning area boundary, adopted the ‘Hellbranch Overlay’ University and the Building only the information for Hellbranch (Columbus Code 3372.7), a codified Industry Association (BIA). The Run is presented with the standard for stormwater result of the EAG process was a understanding that the water management that applied to all November 2004 report that outlined quality initiative within Accord will land development within the city consensus and non‐consensus be influenced by those values. limits and within the Hellbranch recommendations related to these Run Watershed. The provisions of issues. [Note: the EAG was unable Discussion of Current Water the overlay remain in effect even to address the issue of adequate Quality Initiatives with the City’s implementation of public facilities in the timeframe There are several existing policies, the revised Stormwater Drainage that they were allotted]. regulations, and on‐going Manual, which applies city‐wide. environmental protection initiatives Based on discussions with the Stormwater Drainage Manual that affect the level of development City of Columbus, they would (Columbus) that can occur in the watershed. apply the more stringent criteria to The City of Columbus recently Each of these resources has at least any future development within the released and is enforcing the one of the three essential overlay area. provisions of their revised components of environmental Stormwater Drainage Manual, protection related to water quality: External Advisory Group (OEPA) dated March 2006. The drainage riparian corridor protection In late 2003, the Ohio EPA engaged manual contains policies pertaining (stream setbacks); stormwater in an initiative to develop water to stream corridor protection, and floodplain management, and; quality criteria for an area floodplain preservation, and conservation development. identified as the Environmentally stormwater management. With The resources listed have Sensitive Development Area regard to stormwater management, influenced policy recommendations (ESDA). The initiative is a the manual has detailed provisions in this plan. component of an on‐going update for stormwater controls related to to the 208 Water Quality both the quantity and quality of Management Plan for the central stormwater runoff released from a Scioto River basin, which includes development site. The manual Franklin County and the Big Darby provides design criteria for the Watershed, which is described structural components of a below. The ESDA is a portion of the stormwater system, such as curb Big Darby Watershed and is located inlets and storm sewer pipes, as within the western limits of well criteria for features related to Franklin County. The Ohio EPA post‐construction water quality, required that these initiatives be such as extended detention basins developed and enacted prior to the and bioretention facilities. extension of centralized sewer services into this area.

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NPDES Phase II (Franklin County) Fundamentally, the post‐ Watershed and makes reference to Phase II of the National Pollutant construction standards require the the water quality criteria from the Discharge Elimination System implementation of some sort of 208 Plan and is also based on the (NPDES) program is being structural BMP for all development water quality goals established by implemented by Franklin County to sites larger than one acre. For larger the TMDL report. The Ohio EPA is include unincorporated areas development sites, greater than five authorized to regulate stormwater within the County, including the acres, the standards are more discharges under the statewide various townships within the specific and require a BMP facility NPDES program permit. The Accord planning area. The Cities of with a prescribed water quality conditions of the permit apply Hilliard and Grove City are also volume and residence (drawdown) when land disturbing activities participating Phase II communities, time for the intercepted stormwater occur in excess of one acre, at which and the City of Columbus is a runoff. Presently, the Ohio EPA is time the applicant must submit a Phase I community. in the process of updating the Notice of Intent (NOI) to the Ohio NPDES permitting process for areas EPA along with technical The NPDES initiative within within the Big Darby Watershed. information demonstrating Franklin County is being conducted compliance with both construction in cooperation between the County 208 Plan (OEPA) phase and post‐construction water engineer’s office and the Franklin The Ohio EPA is currently engaged quality standards, described Soil and Water Conservation in an update to the 208 Water previously. Currently, the revised District (FSWCD). This initiative is Quality Management Plan for the stormwater permit is in draft form intended to develop stormwater central Scioto River basin. The 208 and the Ohio EPA is considering management standards including Plan is comprised of criteria and comments submitted during the water quality considerations standards related to providers of public comment period. consistent with those mandated by central sewer service. The plan the Ohio EPA through their establishes the municipal Hellbranch Watershed Forum statewide general permit for jurisdictions and other entities The Hellbranch Watershed Forum stormwater discharge. responsible for providing sewer (HWF) is an on‐going initiative that Furthermore, through the NPDES service and the service areas they involves a local stakeholder group program, the County is are responsible for. As mentioned that is similar to the one identified investigating the regulation of above, the plan update included the within the EAG and is being certain on‐lot home septic systems EAG process that established partially funded by the US Army as ‘illicit discharges’ when those recommendations for water quality Corps of Engineers. The FSWCD is systems fail to function as intended. initiatives that would need to be serving as the local sponsor for the implemented by the recognized project and is leading the local The NPDES program and the State service providers prior to extending stakeholder group. The HWF has of Ohio’s general permit for service into the ESDA. The draft been developing policy stormwater discharge address revised 208 Plan contains an recommendations related to requirements related to both Appendix (9‐3) that outlines riparian buffer protection, and construction‐phase and post‐ specific water quality provisions for stormwater and floodplain construction water quality. The Big Darby Creek. Furthermore, that management. These portion of the general permit that appendix has even more specific recommendations have been addresses construction‐phase water quality criteria related to the provided to the Accord for activities includes a requirement for portion of the watershed within consideration and are summarized a Stormwater Pollution Prevention Franklin County, reflecting the in the Hellbranch Watershed Action Plan (SWPPP) containing consensus recommendations of the Plan document. The provisions for erosion and sediment EAG process. recommendations have been control for areas denuded during developed in cooperation with the construction. The post‐construction Stormwater Permit (OEPA) engineering consultant to the HWF, requirements identify the necessary The 208 Plan itself is not a Fuller, Mossbarger, Scott & May components of a permanent regulatory tool for implementing Engineering, Inc. (FMSM) and on‐site stormwater management water quality standards. As such, represent a consensus process facility that provide for long‐term the Ohio EPA has created a draft among the local stakeholder group water quality. revised stormwater general permit that makes up the HWF. that is specific to the Big Darby

B I G D A R B Y A C C O R D C H A P T E R 2 . 0 ― P L A N F R A M E W O R K / 2-21 TMDL Report (OEPA) The TMDL (Total Maximum Daily Load) Report for Big Darby Creek Watershed represents a significant water quality initiative. The information presented previously regarding the Hellbranch Run Watershed is the basis for the water quality modeling performed as part of the Accord planning effort. The specific pollutants and stipulated reduction goals in the TMDL are the foundation for stormwater BMPs that are recommended within the Accord planning area.

Adaptive Management The overall goal to improve and maintain water quality within the Accord planning area is a long‐term process that will require the use of adaptive management techniques. Currently, the Ohio EPA TMDL, Section 208 water quality planning, permits for wastewater and stormwater discharge, and various environmental policies are used to guide development. With the implementation of the Accord Plan, development will be guided by new standards intended to help reach the goals of TMDL. Despite these various measures of oversight and enforcement, a broader program related to the evaluation and monitoring of the watershed and specific stormwater management features that may be implemented is needed to realize an adaptive management approach. Big Darby Creek Source: Metro Parks/Mac Albin

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3.0 Land Use Plan

The land use plan is based on US Environmental Protection • Preserve large, continuous sound planning and Agency. The EPA has developed areas of open space; environmental principles critical a report on protecting water • Preserve critical ecological areas, to balancing growth while resources while allowing for such as wetlands, floodplains, and protecting water quality. These development that indicates riparian corridors; and principles include several key three key goals to protecting • Minimize overall land disturbance strategies identified by the water quality: and direct connection of impervious surfaces associated with development.

Key Recommendations To achieve these goals, the • Protect Tiers 1, 2 and 3 within the Land Conservation Strategy to create a general land use plan includes a network of green infrastructure. strong land conservation strategy,

• Focus land acquisition efforts to Tier 1 and 2 areas where resources are described in Section 3.1. This most sensitive. strategy is based on the environmental sensitivity • Support local organizations and agencies that are actively involved in land conservation efforts. analysis and incorporates a range of tools and techniques to help • Promote regional recreational trail development. conserve critical resources and • Adopt conservation development land use and zoning with 50% open space for rural improve water quality. areas that are not served by central sewer in Prairie, Brown and Pleasant Townships

• Adopt conservation development land use and zoning at 1 unit per acre with 50% Second, the plan focuses a portion open space in the Hilliard growth area, which will be served by central sewer. of the development within a • Create a new destination with a high density mixed use town center between West higher density Town Center Broad Street and Interstate70, which will be served by central sewer. located between West Broad • Adopt new Town Center zoning with base minimum densities, locating the highest Street and I‐70. This Town Center density in the core area of the Town Center with transition to surrounding uses. encourages higher density • Provide supporting institutional uses in the town center and where appropriate. development within a limited

• Provide areas for mixed land to support residential development. area, an approach supported by the US EPA in a publication • Continue agricultural uses in southwest portion of the planning area. called “Protecting Water • Improve and enhance US Route 40. Resources with Higher‐Density • Complete an Interchange Justification Study. Development.” This reports

• Incorporate Leadership in Energy and Environmental Design (LEED) principles of compares analysis of several design, particularly Neighborhood Design (ND) into site design. scenarios of development within a watershed, and indicates that • Apply low impact development (LID) techniques into site design and revise regulations to allow implementation of LID. the same amount of development equally distributed across the • Support the 22 development principals from Darby Creek Watershed Stormwater Management Strategies and Standards for New Development.

• Support principals from EPA National Management Measure to control non-point source pollution from Urban Areas. Section Outline PG 3.1 Conservation Strategy 3-2 • Achieve the water quality goals set forth by OEPA TMDL, for TSS, N and P through changing land uses and application of best management practices. 3.2 Existing Land Use 3-8 3.3 Proposed Land Use 3-13 • Encourage the application of best management practices on agricultural lands. 3.4 LEED Principles • Enhance stream morphology through restoration efforts in the priority stream of Design 3-20 restoration zone along Clover Groff and Hamilton Runs and the upper portions 3.5 Water Quality 3-20 of the Hellbranch Run. 3.6 Stream Restoration 3-29 • Promote regional stream restoration that allows connectivity to other watercourses. 3.7 Floodplain Management 3-35

B I G D A R B Y A C C O R D C H A P T E R 3 . 0 ― L A N D U S E P L A N / 3-1 watershed creates a higher 3.1 Conservation Strategy Purpose amount of impervious cover and The land conservation strategy is a higher amount of runoff than The Darby watershed is home to formulated on the environmental the same amount of development several State and federally listed sensitivity analysis described in clustered into a smaller area. endangered species and is truly a Section 2.3 and is presented in a Therefore, the general land use jewel of Ohio and the Midwest. To system of environmental plan illustrates a pattern of more further protect this valued conservation zones identified as concentrated development as part watershed, an increased level of Tiers. It is the goal of this Plan to of the Town Center. protection is needed to protect encourage the protection and water quality and preserve the conservation of all land within the The general land use plan is the natural resources and unique Tiers. Since green infrastructure sum of two interrelated parts: a character of the area. elements provide communities with land conservation strategy and a an ecological framework, it is land use plan. To achieve the This planning effort represents a essential to identify and protect Mission of the Accord, both the significant opportunity to these areas prior to development. In land conservation strategy and proactively protect resources which addition, restoring natural systems the land use plan will need to be directly and indirectly contribute to throughout the watershed is far pursued simultaneously with biodiversity, improved water more expensive than protecting new policies and standards of quality, habitat areas, and undeveloped land, and man‐made development that are more fully ecological processes of the Darby wetlands and other restoration described in Section 4.0. watershed planning area. Increased projects often fail to function as protection in the form of land well as their natural counterparts The Big Darby Accord Plan conservation and stewardship can over the long run (Benedict, recognizes the property rights of only improve conditions of water McMahon, 2002). landowners in the watershed and quality and will contribute has developed polices to provide positively to retaining the unique Responsible land conservation and several options for landowners. character of the area. open space protection includes Property owners retain the right deciding where development to develop their land under the A grand opportunity deserves a should and should not occur. In governing policies and bold direction. Through land areas where development has regulations, subject to all conservation and stewardship already occurred it is still important environmental standards and efforts, the Big Darby Accord Plan to assess where restoration could requirements set forth by sets forth a goal of protecting about occur to restore habitat areas and regulating agencies such as the 25,000 acres of land within a improve the overall environmental Ohio EPA as well as new comprehensive green infrastructure conditions. Over time, the Land standards set forth in this plan. network consisting of Conservation Strategy should guide Landowners retain the ability to environmental conservation zones the location of development and sell their land or participate in (Tiers) that include existing parks provide a blueprint for regional new programs recommended in and easements, riparian corridors, open space programs and Section 5.0. Some of these easements, open spaces, greenways acquisition efforts, which are more programs include tax benefits for and trails. This network will be fully explained in Section 5.0. landowners. achieved by working together with local jurisdictions, developers, landowners, and conservationists using a variety of existing and new programs, careful planning and development, and spirited cooperation.

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Green infrastructure is our Benefits of Open Space While open space generates less nation’s natural life support A green infrastructure is based on property tax revenue per acre than system – an interconnected connecting people to green spaces developed land, major findings network of waterways, wetlands, and parks and linking together show that open space actually woodlands, wildlife habitats and natural areas to benefit biodiversity produces an overall tax revenue other natural areas; greenways, and minimize habitat surplus which subsidizes other parks and other conservation fragmentation (Benedict, land uses, and open space provides lands; working farms, ranches McMahon, 2002). Integrated public and environmental benefits and forests; and wilderness and systems of open space promote the that more than compensate for other open spaces that support movement of species and the preferential tax costs (Economic native species, maintain natural preservation of ecological processes Benefits of Open Space, Miller, ecological processes, sustain air critical to a healthy ecosystem. In 1992). Development often costs and water resources and fact, in 1999 the President’s Council more in services (health and safety contribute to the health and on Sustainable Development services, traffic, community quality of life for America’s identified green infrastructure as a facilities, utilities) than it pays in communities and people.” key component in comprehensive taxes resulting in a net increase in approaches to sustainable the local tax rate for the public. Definition of Green Infrastructure, community development (The Residential development as noted in Renewable Resource President’s Council on Sustainable expenditures often exceed revenues Journal, Autumn 2002 in an article Development, Towards a while farmland and open space entitled Green Infrastructure: Sustainable America, 1999). revenues (as well as commercial Smart Conservation for the 21st and industrial) exceed Century, by Mark Benedict and Conservation is sound investment. expenditures. Edward T. McMahon. Development that destroys or degrades natural features and Numerous studies highlight resources is environmentally and specific open space attributes that economically wasteful. Protection can be used to establish economic of natural features provides a value. Measurable attributes of public benefit to all. open space include things like biological diversity, wildlife habitat, soil conservation, rural character, flood control, quality of life, cost efficient development, climate control, fishery protection, scenic views, scientific opportunity, forestry, public access and many more (Miller, 1992). Assigning monetary values to these attributes can depict significant economic value to open space. One direct benefit of open space is the increase in adjacent property values.

B I G D A R B Y A C C O R D C H A P T E R 3 . 0 ― L A N D U S E P L A N / 3-3 3.1.1 Conservation Strategy in Franklin County”. Their services Components Conservation include education, public Category Acres The land Conservation Strategy is information, construction and post Protected 4,310 comprised of a system of elements construction review and inspection, including areas already protected Existing 6,131 backyard conservation, under existing regulations, existing Tier 1 5,790 conservation implementation on parks and easements, and proposed Tier 2 1,885 private lands, county drainage tiers. The Tiers are based on a mapping layer, and conservation Tier 3 7,150 number of factors and include easements. Total 25,266 features that were part of the sensitivity analysis described in Figure 3.1 Conservation Categories Other municipal parks are located Section 2.3. Specific policies related Acreages throughout the planning area. to the regulation of elements within Note: About 1,300 acres within Increased development westward Metro Parks is classified in the the conservation strategy, i.e. Protected Category. into the planning area as well as riparian corridors, floodplains, etc., planned future development areas are further discussed in Section 4.0. identified in this plan will require Existing Parks and Easements additional park land and facilities, The goal of this plan is to protect all The Battelle Darby and Prairie Oaks including active recreation fields lands within the land Conservation Metro Parks encompass and protect for soccer and other organized Strategy. Property owners holding almost 7,000 acres within the sports. Development of this plan land within the Tiers will be planning area. These parks, located does not include a needs encouraged to participate in along the banks of the Big and Little assessment to determine the voluntary conservation programs Darby Creeks, include significant number of fields, type of facilities, while the Accord jurisdictions will riparian zones, forests and open or other specific detail; however, work collectively to implement space, and together, represent the this plan has identified general regional open space programs with single largest contiguous tract of areas for future facilities based on key partners. Existing development land currently in conservation the general land use plan. and any newly proposed within the planning area and in Generally, the location of facilities development in the Tiers will need Franklin County. The mission of should maximize access and be to occur in accordance with Metro Parks is compatible with the centrally located to neighborhood applicable base zoning regulations creation of a land conservation centers. and other standards for strategy for the Accord planning development including best area and Metro Parks is a management practices. Policies formidable partner in related to the types of appropriate implementing the Accord Plan. The activities, land management Metro Parks Strategic Plan, 2005 approaches and other identifies habitat restoration areas, considerations for the Tiers are community restoration areas, described in Section 4.0. community open space and a greenway trails system. The Accord Overall, the land Conservation Plan fully supports the efforts of Strategy shown in Figure 3.2 Metro Parks. identifies approximately 25,000 acres of land in five categories Franklin Soil and Water outlined in Figure 3.1. Conservation District (FSWCD) currently has easements on 145 acres of land within the planning area. The FSWCD mission is to “promote responsible land use decisions for the conservation, protection and improvement of soil and water resources by providing assistance through effective partnering and technical guidance

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Figure 3.2 Conservation Strategy

B I G D A R B Y A C C O R D C H A P T E R 3 . 0 ― L A N D U S E P L A N / 3-5 Protected Zone ground, slowing water flow and improve water quality, slow run‐ Today, current regulations provide allowing groundwater recharge. off, and provide a transition for the protection of about 4,300 Floodplains in their natural state between other open space, acres of land that is encompassed are beneficial for a number of developed land, and the streams. by the FEMA designated floodway reasons: Riparian corridors at a minimum or calculated beltwidth. Because • Reducing the number and include the 100 year floodplain or these elements are already severity of floods Beltwidth, which ever is greater. protected by regulations or • Minimizing non‐point source water For the purposes of this plan, ordinances, they have been pollution policies related to the riparian categorized separately and will • Filtering storm water corridor are addressed in the retain their protected status in this • Providing habitat for plants Stream Corridor Protection zone in plan. This plan will maintain the and animals Section 4.0. In some cases, current level of protection and • Aesthetic beauty and outdoor particularly along the Big Darby recommends local jurisdictions put recreation benefits. Creek main stem the riparian in place policies to protect further corridor is vast due to floodplain Tier 1, 2 and 3 areas. Until those Floodplains are home to many and other natural resources found policies are developed and types of plants and animals and within the zone. adopted, development in Tiers 1, 2, may also have forests and wetlands and 3 could occur at the current on or adjacent to them. These river Riparian zones typically comprise a permitted level, subject to all other edges provide habitat for insects, small percentage of the landscape, regulations. birds, reptiles, amphibians, and often less than 1 percent, yet they mammals. The vegetation helps frequently harbor a Tier 1 filter contaminants out of the water disproportionately high number of Land within Tier 1 is considered the flowing into the river. Additionally, wildlife species and perform a primary priority for protection vegetated floodplains provide disparate number of ecological through land acquisition and other shade for the adjacent rivers and functions compared to most upland programs. Encompassing about streams, increasing dissolved habitats. Riparian zones have been 5,800 acres, resources within Tier 1 oxygen levels and consequently widely recognized as functionally are significant in maintaining the improving habitat for aquatic unique and dynamic ecosystems overall health of the watershed. plants and animals (Center for only within the past Resources in Tier 1 include the 100 Earth and Environmental Science, 25 years (US Army Engineer year floodplain, wetlands, critical Indiana University‐ Purdue Research and Development groundwater recharge and University). Center, Environmental Laboratory, pollution potential zones. The April 2000). protection of these elements The effectiveness of a stream’s provides a buffer for sensitive in‐ floodplain to convey and store Wetlands stream habitats. Stream corridor flood water can be adversely For the purpose of a land protection zones and floodplain affected by human activity. conservation strategy, wetlands protection policies are described in Development practices within and are included and categorized Section 4.0 and have been along floodplains affects the land’s under the umbrella of open space. recommended as guidelines for the ability to absorb rain and Wetlands are a natural feature minimum standard of protection. floodwaters and can contribute to within the landscape that offer flood events that are larger and multiple benefits to water quality Floodplains more frequent leading to increases and habitat and therefore should Floodplains are defined along the in property damage and life be preserved and protected. banks of rivers, streams, or creeks threatening situations. National or state wetland as areas that may be inundated inventory data is a starting point with water following heavy Riparian Corridors to identify wetlands; however, rainstorms. During high water Riparian corridors include grass, due to differences in scale and events, floodplains absorb water trees, shrubs or a combination of changing environmental factors it and help prevent rivers, streams natural features along the banks of is important to evaluate the and creeks from overflowing. streams that serve to filter presence of wetlands on a site by Water expands into the floodplain pollutants, provide stream bank site basis through the areas and infiltrates into the stability, protect stream species, development review process.

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This type of analysis ensures all drainage systems, resulting in a Tier 3 wetlands are properly identified decrease in the amount of Land within Tier 3 is considered a and delineated allowing for groundwater returned to the tertiary priority for protection increased protection. surface elsewhere. through land acquisition. These areas should be conserved through Groundwater Recharge and Pollution Tier 2 permanent conservation easements, Potential Zones Land within Tier 2 is considered a within conservation development Groundwater and surface water are secondary priority for protection subdivisions and other suitable fundamentally interconnected and through land acquisition and other mechanisms. Tier 3 is envisioned as are integral components of the programs. Encompassing providing an integral piece of the hydrologic cycle. Because the approximately 1,885 acres, open space network by creating quality and quantity of surface resources within Tier 2 include linkages among all other waters can be dramatically affected highly erodible soils, and components of the Land by groundwater contributions, contiguous wooded areas that are Conservation Strategy. Passive preservation of the water resources greater than three acres in size. recreation and certain types of in the Darby Creek planning area sensitively designed active requires considerations for the Highly Erodible Soils recreation should be considered protection of groundwater quality Highly erodible soils are those that suitable for Tier 3 areas. and recharge capacity. have a high potential to erode Groundwater entering surface based on their physical and The overall goal of creating a waters most frequently comes from chemical properties when network will only be possible unconfined (water table), shallow combined with particular climatic through careful planning and aquifers. These aquifers interact conditions. Within the planning efforts to link existing and future closely with streams, sometimes area, nineteen (19) soils are conservation lands. Corridors of discharging water into a stream or categorized by the NRCS as highly conservation promote habitat lake and sometimes receiving water erodible, four (4) as potentially movement and diversity and can from the stream or lake. An highly erodible, and two (2) as not lead to increased recreational unconfined aquifer that feeds highly erodible. These designations opportunities while preserving streams provides the streamʹs base are important for federal rural character. Land within Tier 3 flow, and the stream is called a agriculture programs. provides buffers and linkages “gaining” stream. Because of this around areas that have been base flow support, groundwater is Wooded Areas associated with unique habitat, often responsible for maintaining While wide, intact, wooded including enhancing the riparian the hydrologic balance of surface riparian corridors are a crucial corridors along some stream streams, springs, lakes, wetlands factor in the overall aquatic and corridors. Approximately 7,150 and marshes. Therefore, to fully terrestrial species diversity and acres are identified as Tier 3. understand the source of the stream richness within the Big Darby baseflow and its contribution to the Creek watershed, wooded parcels Habitat Connectivity and Buffer Areas stream system habitat, knowledge (and wetlands) removed from the Due to the unique aquatic of the unconfined aquifers adjacent riparian corridor also have environment within the Big Darby to streams is essential. significant, but lesser benefits to the Creek Watershed and particularly overall habitat condition. Wooded along the main stem of Big Darby The source of recharge to the parcels greater than three acres Creek, a significant number of groundwater regime is infiltration have been included in Tier 2. threatened and endangered species of precipitation through the soil or Connectivity between wooded are present. Protection of these percolation of surface water parcels is beneficial for wildlife important habitats is accomplished through the substrata of streams, movement and expansive areas of through the Endangered Species lakes, wetlands and marshes. woodland offer excellent Act (ESA), enacted by the U.S. Recharge to shallow, unconfined opportunities for reducing Government in 1973. In addition to aquifers can be locally restricted stormwater runoff and erosion and the Federal protected species list, through the creation of impervious increasing surface water infiltration Ohio has its own list of State areas (buildings, roads, parking and groundwater recharge. threatened and endangered species lots, etc.), lined or armored stream that require protection. channels, and artificial subsurface

B I G D A R B Y A C C O R D C H A P T E R 3 . 0 ― L A N D U S E P L A N / 3-7 The Natural Heritage Database is a changes form, and their long‐term 3.2 Existing Land Use compendium of records of rare viability must be considered in the plants and animals, high quality planning process. Existing land uses are described plant communities, special animal below, followed by a description assemblages or colonies, and other Trails of the proposed general land use natural features within Ohio. The Trails within the watershed plan. Acreages have been database search revealed the offer residents and visitors an determined using GIS and should presence of two (2) Federal opportunity to explore nature, be considered estimates for Endangered species, one (1) Federal take part in a healthy activity by master planning purposes only. Candidate species, eleven (11) State walking, biking or hiking, and Endangered species, seven (7) State can contribute to a better Figures 3.3 and 3.4 depict the Threatened Species, four (4) State understanding of the dynamic existing land use within the Big Potentially Threatened species, and nature of the watershed. Trails Darby Planning area. This six (6) State Species of Concern. already exist within the Metro Park information is based on a Records of mollusk beds and glacial system and efforts are underway to combination of sources including erratics (rocks or boulders expand the Metro Park trail system data from the Mid Ohio Regional deposited by glacial movement) to include a more comprehensive Planning Commission (MORPC), were also noted. network of trails throughout the information from the local watershed. This plan supports the jurisdictions such as comprehensive As expected, the highest concen‐ efforts of MetroParks in their plans, and aerial photography tration of rare species is located pursuit of a regional trail network, obtained through the Franklin within the Big Darby Creek main including efforts to connect with County Auditor, 2002. The existing stem and within the downstream regional trail systems that extend to development pattern shows a portion of Little Darby Creek near Cincinnati and Cleveland. higher concentration of residential the confluence. Essential to support uses along the eastern boundary of sensitive species, these areas Trail systems should be considered the planning area, along the edges provide the best quality habitat an integral part of community of Hilliard and Columbus and (evidenced by OEPA QHEI scores) development; serving as a link generally east of Alton Darby Creek and have the greatest amount of between neighborhoods, activity Road. The remainder of the wooded riparian buffer within the centers, employment areas, schools planning area is mostly agriculture watershed. and public facilities and other with pockets of rural residential destinations. From a regional developments. The subdivision of A number of the species listed in perspective, trails attract visitors lots has created rows of very deep 5 the planning area are static species supporting the local tourism and acre lots or larger along rural or communities, as indicated on travel industry; however, their roadways while the interior portion Figure 2.8. Static species are primary emphasis in the Darby of the tract remains active generally unable to move around, watershed planning area is to agriculture. or to move great distances, under encourage a healthy lifestyle and their own power. Mussels and elevate the quality of life for plants fall into this category. Static existing and future residents. species are more susceptible to Developers should coordinate with habitat destruction and point Metro Parks and local jurisdictions source pollution than motile to connect neighborhood trails with species, which can move upstream regional trail systems, creating a or downstream relatively quickly in web of off‐road connections that response to an impact. For this improves safety and creates reason, static species should receive recreational value. Trails should be special consideration when considered during roadway planning disturbances within the improvement projects; funding watershed. As a general rule, for trail projects could be however, all threatened or allocated when funding is pursued endangered species are subject to a for transportation‐related number of forms of habitat infrastructure. degradation as the landscape

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Open prairie lands Large-lot development Suburban-style development Source: EDAW Source: EDAW Source: EDAW

Based on a GIS analysis, about 26% Of the 12,000 acres of residential Existing Land Use Categories of the planning area is developed, development, about 4,800 acres is An effort was made to incorporate accounting for almost 14,000 acres, very low density rural existing uses based on their own not including existing parks. For development. Less than 1,000 acres unique description and not try to the purposes of calculation, large is considered medium or high assimilate the existing uses into lot parcels with only one home that density (5 units per acre or greater). new land use categories. Existing may have additional development Figure 3.3 lists existing land uses development is indicated by the use capacity were assumed to be fully and estimated acreages. of a hatch pattern on the land use developed. It is estimated that map. The following categories on about 19,000 residential units The existing development pattern the proposed land use map are already exist within the planning reflects the continued growth of the related to existing development. area as well as existing commercial, urban and suburban development Note that mixed use, commercial, public, park and other uses. patterns to the west. A range of public/institutional and agricultural residential development densities uses relate to proposed land uses Existing residential land uses, occurs along the eastern edge of the as well and are listed under both including some small urban, planning area. Limited areas of existing and new land use suburban and rural development commercial uses, golf courses, categories. account for about 22% (12,000 parks and other public/institutional • Rural Residential Estate: Lots that acres) of the planning area. uses also exist in the planning area. are greater than 5 acres in size • Residential Rural: 0.2 ‐ 0.5 dwelling Existing Generally, west of the Hellbranch units per acre Land Use Acres Percent Run the development pattern is • Residential Suburban: .5‐3 dwelling Agriculture 31,536 56% lower density with several pockets units per acre Commercial 218 <1% of higher density residential • Residential Urban Medium Density: Industrial 29 <1% particularly along West Broad 5‐8 dwelling units per acre Public / Street within Prairie Township and • Residential Urban High Density: 1,355 2% Institutional the City of Columbus. The Greater than 8 dwelling units per acre Residential 12,083 22% remaining areas generally include • Industrial: Light industrial uses such Rural Estate 4,805 agriculture uses and larger lot as warehousing, technology or Rural 3,132 single family residential areas. business parks Suburban 1,890 Agriculture uses occupy • Mixed Use: A mix of residential and Suburban High approximately 56% of the planning commercial/retail uses. Actual 1,396 Density area, or 31,000 acres. About 200 densities for existing mixed use areas Urban Medium 480 acres of commercial development is were not determined but were ( 5 - 8 du/ac) clustered near the intersection of assumed to be between 3‐5 dwelling Urban High 380 ( > 8 du/ac) Route 62 and I‐70 and in the units per acre Parks & Open vicinity of Scioto and Darby Creek • Commercial: Local or regionally 7,490 13% Space Road. Existing parks and open serving commercial and office uses Golf 782 1% space, including Metro Parks, such as groceries, big box stores Roads 2,536 5% account for approximately 13% • Public/Institutional: Schools, Total 56,029 100.0% (7,443 acres). community facilities, government services, libraries Figure 3.3 Existing • Agriculture: Farmland Land Use Acreages

B I G D A R B Y A C C O R D C H A P T E R 3 . 0 ― L A N D U S E P L A N / 3-9 Figure 3.4 Existing Land Use Map

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Parks and Trails Acres Description Owner Alton Road Parkland/Clean Ohio Parkland 103 Undeveloped and Conservation Stewardship Columbus Battelle Darby Creek Metro Park 6,251 Woodlands, Conservation Metro Parks Clover Groff Natural Area 25 Mitigated Wetland Area and Nature Preserve Columbus Franks Park 54 Neighborhood Park Columbus Hilliard Municipal Park (Includes Soccer 133 Athletic Fields, Pool, Senior Center, Hilliard Park, Latham Park) Community Center, Bike Park, Tennis, Picnic Shelters, Amphitheater Prairie Oaks Metro Park 715 Woodlands, Conservation Metro Parks Spindler Road Park 109 Soccer Complex and Stream Corridor Buffer Columbus Wexford Green Park 9.8 Playground, Woodlands Columbus Total 7,399 Figure 3.5 Existing Parks Sources: Columbus Park and Recreation Department, Hilliard Parks and Recreation Department, Metro Parks. Note: Metro Parks acreages include only the area of the park that falls within the Accord planning area.

It is not the intention of the general million visitors per year. Their Metro Parks promotes partnerships land use plan to recommend that mission is to conserve open spaces, with willing land owners and existing development should be while providing places and jurisdictions to acquire additional removed or redeveloped to be opportunities that encourage park lands. Future goals of Metro consistent with Figure 3.6. Rather people to discover and experience Parks are outlined in a 2005 the land use plan is intended to nature (Metro Parks Community Strategic Plan and include illustrate how new Update, 2004). Metro Parks’ land additional park lands and the development should complement management practices include creation of a greenway trail system the existing development patterns. wetlands restoration, prairie linking Battelle Darby Creek Metro restoration, wildlife management Park with Prairie Oaks Metro Park. Existing Parks and Recreation programs, farming, and species Based on existing land use data, monitoring. With the exception of Metro Parks, about 7,399 acres of parkland parks within the planning area vary currently exist within the planning in size and are generally located area and is provided by many “Conservation and preservation along the West Broad Street jurisdictions. The majority of of the best remaining natural areas corridor or in the northern portion parkland is concentrated in Metro is an important responsibility of of the planning area, along Clover Parks along Big Darby Creek. The Metro Parks” Groff Run. Hilliard Municipal Park largest park, Battelle Darby Creek Metro Parks Community Update, 2004 at 133 acres is the third largest park Metro Park, is also the largest park in the planning area and offers a within the Metro Park System. mix of activities including a Prairie Oaks Metro Park provides Metro Parks started acquiring land swimming pool and athletic fields. an additional 715 acres of park land in the Darby watershed in 1948 Spindler Park and Alton Road Park in the planning area. Heritage Park with a purchase of 113 acres. Since are the next largest park facilities in Metro Park, 58 acres, is located just then, the system has grown to over the planning area at 109 and 103 outside the planning area long the 23,000 acres, focusing on acres respectively. Together these Heritage Trail near Hilliard and conserving significant natural three parks offer about 300 acres of offers a respite for trail users. features and resources. Metro Parks parkland to residents in the central owns over 8,100 acres in the Darby and north part of the watershed. Metro Parks serve a regional area watershed (about 7,000 acres in Other parkland accounts for less and provide Franklin County planning area), with about half of than 100 acres. Homestead Park in residents with direct access to those acres acquired since 2000. Washington Township is located natural resources through creative Programs and initiatives are funded along the planning area boundary programming and education, through a 0.65 mill property tax and provides facilities. By contrast, events and land stewardship. Metro levy that extends to 2009 as well as the majority of parks in the Parks estimates it receives about 5.5 other state and federal resources, southern portion of the planning private donations, and grants.

B I G D A R B Y A C C O R D C H A P T E R 3 . 0 ― L A N D U S E P L A N / 3-11 area are part of the Metro Parks Metro Parks and Columbus system. Recreation and Parks are working to develop a greenway trail along The Westland Area Commission is right‐of‐way of the Camp Chase currently undertaking a recreation Rail corridor that when complete, facilities study. The Department’s will be an important regional recreation service delivery linkage for central Ohio. The Camp standards established in the 2003 Chase Rail Corridor could Columbus Recreation and Parks potentially connect into the Ohio‐ Master Plan show a need for a Erie trail systems of Cincinnati and recreation center in this area. Cleveland. Columbus is also Columbus is interested in planning a connecting trail along establishing partnerships with the Clover‐Groff Run. Additional other jurisdictions to deliver and connections along Big Run Creek maintain recreational services. would link this corridor to the Scioto River Greenways Corridor. Trails and Greenways Trail systems or greenways within Golf Courses the planning area are generally Golf courses within the planning confined to existing park systems. area are generally evenly dispersed. Efforts to expand the greenway and However, most of the courses are trail system within the planning privately operated and require area and County are underway. membership for access. The five The park agencies in Franklin golf courses within the planning County are partnering to deliver an area include: Heritage Golf Club interconnected multi‐use trail (private), Hickory Hills Golf Club system. The Heritage Rail Trail near (private), Mentel Memorial Golf Hilliard is a seven‐mile multi‐ Course at Bolton Field (public), purpose trail from Old Hilliard to Oakhurst Country Club (private), Plain City along the northeastern and Thorn Apple Country Club planning area boundary and (semi‐private). provides a dedicated corridor for walking, jogging, bicycling, rollerblading and horse back riding. This effort is jointly managed and owned by Metro Parks and the City of Hilliard.

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3.3 Proposed Land Use

The proposed general land use • Incorporate the sensitive natural Conservation Land Use Categories plan, shown in Figure 3.7 is areas as part of a tier system that Land uses related to conservation, guided by several key concepts. includes a protected zone as well as as described in Section 3.1, are an • Focus higher density development in areas that should be targeted for important part of the proposed a town center located between I‐70 protection in Tiers 1, 2 and 3. land use plan and are referenced and US 40. again below. • Incorporate additional areas of higher The proposed general land use • Protected Zone: FEMA designated density adjacent to the existing plan categorizes future land uses floodway or calculated beltwidth on development of Hilliard and the City within the watershed into all stream channels of Columbus along the eastern edge generalized land use categories. • Tier 1: 100‐year floodplains, of the planning area where utility These categories were developed wetlands, high potential groundwater service can be provided. with consideration of current pollution, high groundwater recharge • Provide for a Hilliard growth area types of development in the areas that includes conservation watershed as well as standard • Tier 2: Highly erodible soils, wooded development of 1 unit per acre. categories that are typically found areas greater than 3 acres • Provide several larger areas of in community land use plans. • Tier 3: Endangered habitat sensitive conservation development in Brown, The following paragraphs briefly zones, proposed parks, corridors and Prairie and Pleasant Townships – describe all the land use connections, trails these are the areas that are unlikely to categories, both conservation • Parks: Existing parks be served by sewer service. and development categories, • Golf Course: Existing golf courses that are part of the proposed general land use plan. Development Land Use Categories Categories of land use have been developed to provide for future Proposed Generalized Land Use Categories Acres Percent residential, commercial and Agricultural Use 3,356 6% institutional uses. These include the Commercial 196 0% following Industrial 50 0% • Conservation Development Low Public / Semi Public 1,053 2% Density: 50% open space at 1 Mixed Use 357 1% dwelling unit (du) per acre; sewer Res Conservation Devp 50% Open Rural densities 9,406 17% service required Res Conservation Devp 50% Open 1 du/ac 1,189 2% • Conservation Development Rural Rural Residential 1,026 2% Density: 50% open space based on Rural Estate 4,805 9% existing zoning; no central sewer Suburban Low Density 0.5-3 du/ac 149 0% provided Suburban Medium Density 3-5 du/ac 4,073 7% • Special Pilot LEED ND Residential: Urban Medium Density 5-8 du/ac 130 0% 3 dwelling units per acre and LEED ND certification suggested Urban High Density 8+ du/ac 447 1% • Residential Suburban Density: 3‐5 Special Residential LEED 328 1% dwelling units per acre Town Center* 1,825 3% • Agriculture: Farmland Golf Course** 729 1% • Town Center Zone: Existing Park** 6,266 11% Mixed use residential, retail and EC Protected 4,334 8% commercial center Tier1 5,600 10% • Mixed Use: 5‐8 dwelling units Tier2 1,850 3% per acre with limited neighborhood Tier3 7,160 13% retail uses Roads & Transportation*** 1,701 3% • Commercial: local or regionally 56,029 100% serving commercial and office uses Figure 3.6 Proposed Land Use Categories • Public/Institutional: Schools, *Excludes identified Conservation areas in Town Center (about 675 acres) community facilities, government **Excludes Conservation protected area ***Calculation considers only major roads. services, libraries

B I G D A R B Y A C C O R D C H A P T E R 3 . 0 ― L A N D U S E P L A N / 3-13 Figure 3.7 Proposed General Land Use Map

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3.3.1 Town Center The Town Center concept is consistent with the goals of smart growth. Smart Growth encourages sustainable development that minimizes suburban and ex‐urban sprawl Multi-family housing Single family housing Source: EDAW Source: EDAW and encourages higher density development in urban areas adjacent to transit or other exiting infrastructure systems. Principles of smart growth include: • Mix Land Uses • Encourage Compact Building Design • Create a Range of Housing Opportunities and Choices Mixed use development Town center residential development • Create Walkable Neighborhoods Source: EDAW Source: EDAW • Foster Distinctive, Attractive Communities with a Strong people will still drive to the Town • A variety of neighborhood to Sense of Place Center core, once there, they should regional‐serving commercial, • Preserve Open Space be able to park once and walk to office, and entertainment uses • Strengthen and Direct other destinations. The Town • Well organized public spaces Development toward Existing Center should create an including parks, formal and Communities environment that people will return informal spaces • Provide a Variety of to repeatedly for more than just • Incorporation of historic and Transportation Choices shopping purposes. The Town cultural resources • Make Development Decisions Centers should satisfy everyday • Regional stormwater facilities to Predictable, Fair, and Cost Effective needs and provide enticements to protect water quality and enhance • Encourage Community and linger and relax. natural resources Stakeholder Collaboration in • Community facilities and services Development Decisions The Town Center should evoke • Pedestrian orientated design

special characteristics that set it • Quality design and materials The intention of the Town Center apart from its surroundings and • Access to existing and future transit development is to create a highly contribute to its individuality. The opportunities desirable mixed‐use area that Town Center should strive to create includes a full range of residential, community character with While the general land use plan retail, office and public uses identifiable characteristics which illustrates a zone for the Town including parks and open space. can include: Center, it will likely include a mix Town Center is envisioned as a • Preservation of environmentally of uses developed over time and walkable village that includes retail sensitive areas through phases. The uses are uses facing key streets to create a • Sustainable building practices envisioned to include residential, lively and visually appealing and design retail, commercial, office, community. The streets would have • Mixed uses both vertically and institutional, park, and natural well proportioned sidewalks along horizontally areas. Application of a concept small urban blocks along with • High density development in the core termed ‘transect’ can help provide parks and open space areas to help of the Town Center with transitions form for the town center and ensure ensure a strong pedestrian to surrounding lower density and the edges of the town center ambiance. The Town Center core existing development transition smoothly to less should be a safe, attractive, • A broad range of housing types and urbanized areas. efficient, walkable area with price levels, bringing people of convenient connections to diverse ages, races, and incomes into residential neighborhoods and daily interaction nearby transit. Although many

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Planning Transect “Transect” is a term and concept created by urban planner and architect Andres Duany to illustrate the effective transition from an urban core to a natural setting. This transition, which occurred organically and naturally in the Transect Concept past, now must be carefully Source: Smart Code Version 8.0 considered since current zoning or a town center, while the core is center zone edges related to regulations have separated and typically envisioned as a more existing zoning, environmental segmented uses creating a regional center. features and the provision of disjointed landscape across urban, services should be considered and suburban and rural areas. A transect concept should be addressed in the Master Plan Classified by zones, it is designed applied to the Town Center to process. Initial phasing should to allow for a seamless and orderly provide an acceptable transition begin along West Broad Street. transition between urban and rural from high density to surrounding areas. By developing according to rural developments. The urban core To achieve a successful Town the transect model, single‐use Center, a base level of density zoning is set aside, allowing for the of the town center should gradually recede into more rural style should be established appropriate mix of uses within each within the development like conservation zone and encouraging a mix of core area of Town Center. This base development and open space. design options. On the macro scale, level of density would allow for a Following a transect concept allows the transect can be used to revise mix of uses and encourage the denser, concentrated development existing zoning codes and on the creation of pedestrian friendly in the Town Center to coexist and micro scale it can be used on large environment. Based on successful seamlessly integrate with any scale master plan developments. Town Centers both within central existing development and Ohio and from around the country, environmentally sensitive areas. The transect has six zones it is recommended that the core beginning with the Natural Zone area be developed with a minimum To ensure a well planned and high of 8 units per acre to a maximum of that is conceived as permanently 15 units per acre. Another approach protected open space. This zone quality town center is created, a to managing the density would be transitions into the Rural Zone more detailed Master Plan should based on Floor Area Ratio (FAR). which features large lot be pursued as discussed in Section Floor Area Ratio is a method of development on land that is 5.0. Additional policies related to calculating the building intensity environmentally sensitive and the mix of uses, design and allowed on a site. Floor Area Ratio scenically valuable. The Suburban character of the Town Center are is expressed as Zone consists largely of single described in Section 4.0 the gross floor area family homes but can contain a mix permitted on a site divided by the of appropriate uses within walkable Density / Level of Development total net area of the site, expressed The number of residential units in decimals to one or two places. distances such as neighborhood anticipated to occur For example, on a site with 10,000 retail, schools, and institutional within the net sq. ft. of land area, a Floor Area uses. This mix of uses becomes initial development of the Town Ratio of 1.0 will allow a maximum richer as the transition continues Center is approximately 5,000 units, of 10,000 into the General Urban Zone that based on a sewer capacity analysis gross sq. ft. of building features more residential density. further discussed in Section 4.9. The floor area to be built. On the same The Urban Center and Urban Core total amount of development may site, a FAR of 1.5 would allow Zones are the densest and most increase depending on sewer 15,000 sq. ft. of floor area. To create urban zones in the transect and service availability. Planning and a successful Town Center the FAR design of the Town Center will be would likely be between 1.0 and 2.0. have the largest mix of uses. The driven by the location of available Urban Center Zone can be described as a neighborhood center utilities. Flexibility near the town

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These densities should be development.” The residential further explored and refined zoning ordinances have as part of the detailed Master encouraged such traditional Plan recommended for the designs by requiring minimum lot Town Center. sizes, uniform road frontage and lot setbacks, specific road standards, 3.3.2 Conservation Development and other standard requirements. As Central Ohio has grown, people In general, the only open space Conservation development have migrated to what have within such developments has been Source: EDAW become known as “subdivisions” the yards between adjoining located in more suburban or rural privately owned housing lots. In areas, including the Big Darby many cases, little planning went Accord planning area. Much of this into preserving or improving the type of development has followed a quality of the open‐space areas or traditional design, which some protecting natural features on the have described as “checkerboard or developed parcel. cookie‐cutter housing Conservation development Source: EDAW Highlight on Conservation Development This pattern of land use and land Well-designed conservation developments may benefit the whole consumption has resulted in many community in terms of stormwater management. These developments people asking the question of usually have less impervious surface cover and provide more open space whether we are creating a high for water infiltration. These two factors combined can help reduce the quality of life in our communities. amount of stormwater runoff leaving the property and thus decrease the Conservation development, also chances that the new development will cause flooding problems. Although sometimes referred to as cluster traditional subdivisions may be required to build stormwater detention development, is an approach areas, these structures usually only reduce the flow rate of water, not the to development that allows increased volume. Natural areas, such as wetlands or native plantings that residential development while still are a part of the conservation development’s open space can help manage protecting the area’s environmental stormwater by reducing the volume of runoff and cleaning the stormwater features, allowing for more open during the infiltration process. space, and protecting the rural Another advantage of conservation developments is that they generally use character of the area. less mass grading of the parcel’s soil surface. Such grading can compact the soil and increase runoff even on areas where there is no construction. The rural character of western Road ditches in cluster designs are often grass swales instead of curb and Franklin County is a gutter. These grassy areas allow for more water infiltration and are often contributing factor to the less costly for developers and require less maintenance from the quality of life enjoyed by homeowners’ association or community residents who live in the area. (http://www.urbanext.uiuc.edu/lcr/LGIEN2000-0010.html). Rural character within the Big Conservation development is not a new concept to the Big Darby Accord Darby Accord exists due to the planning area. Prairie Township is developing a planned residential predominance of open space, conservation development overlay district to promote the creation of natural landscape, vegetation conservation developments. Brown Township’s recently adopted in the area and the emphasis Comprehensive Plan identifies conservation development as the preferred on traditional land‐based uses land use for a majority of the rural township. Policies must be adopted and like agriculture. Other rural in place to allow for conservation development, as described in Section 4.0. characteristics include Developers often cite local regulations as the primary reason more significant park lands and innovative designs are not used. More flexible regulations does not mean equestrian activities. Several “anything goes,” however. Traditional codes must be replaced with new small communities exist, such design standards that address the goals of conservation development, such as Darbydale and Georgesville, that provide concentrations of as open space preservation, etc. businesses and homes;

B I G D A R B Y A C C O R D C H A P T E R 3 . 0 ― L A N D U S E P L A N / 3-17 however, a large amount of homes are located on isolated parcels. Typically, rural communities maintain a limited expectation of urban services and infrastructure such as sewer, water, urban roads, curbs and sidewalks Conservation development is a design strategy for residential development that can lead to increased protection of existing natural resources on and off‐site. 20 lots 20 lots Conservation developments 25 acres open space No open space Pond access for all residents No pond access except from four lots incorporate open space as part of the design with consideration of existing site topography, soils, vegetation, natural drainage patterns, and other sensitive or unique landscape features. Protected natural areas provide wildlife habitat, protect biodiversity, and can contribute to improved water quality, regional greenways and natural area networks. Like other land use types, conservation developments integrate stormwater Best These two plans provide the same number of dwelling units. The conservation develoment, Management Practices (BMPs) left, uses smaller parcesl and a range of unit types on a much smaller footprint, allowing the surrounding area to be maintained as open space. The conventional development, right, throughout the site, utilizing the more typical of current residential zoning, offers no open space and limits access to the site’s natural features to protect and pond to those homes which front along it. The amount of roads and infrastructure required restore natural hydrology, habitat for the conventional site development would most likely be greater than costs for the and water quality. Development conservation development. Source: Arendt, 1994. costs for site preparation and stormwater management 3.3.3. Other Residential Uses area should serve as a model infrastructure is often reduced since Along West Broad Street, east of development for sustainable design only a portion of the site needs Hellbranch Run, residential through application of LEED modification. development of 3 to 5 units per acre principles. Application of LEED

is identified. These areas are principles should be encouraged Conservation developments differ expected to have access to central throughout the entire planning from traditional developments in sewer through the extension of the area. LEED is further described in several ways. Conservation Big Run Trunk sewer line to the Section 3.4. developments usually site homes town center. on smaller lots with less emphasis 3.3.4 Mixed Use on minimum lot size. The same Another residential category, The mixed use areas identified on number of homes is clustered on a identified on Figure 3.7 as Special the general land use plan are smaller portion of the total Pilot Leadership in Energy and intended to occur at key locations available land. The remaining land, Environmental Design (LEED) within the planning area. The which would have been allocated to Residential, is located north of I‐70, Mixed‐Use areas are intended to be individual home sites, is now between Clover Groff and neighborhood or community converted into protected open Hamilton Runs. Due to the centers that provide a focus for space and shared by the residents sensitive nature of this location and locating uses that will support of the subdivision and possibly the gateway into the watershed, this surrounding residential entire community.

3-18 / C H A P T E R 3 . 0 ― L A N D U S E P L A N B I G D A R B Y A C C O R D communities. The mixed‐use cooperation with local Big Darby Creek to I‐270 is under designation provides some organizations like Ohio State the jurisdiction of Ohio Department flexibility in what uses could occur University Extension, FSWCD and of Transportation (ODOT). Access in these areas, however, a blend of NRCS, new programs should be points for new developments must residential, retail, commercial, and promoted in the watershed that adhere to the guidelines set forth in institutional is recommended. The creates financial incentives the State Access Management density of mixed‐use areas should encouraging farmers to reduce Manual. Unfortunately, much of be slightly higher than the pollutant loadings. the area east of Hilliard‐Rome Road surrounding lower density has been developed and numerous residential areas they would serve. 3.3.6 Transportation access points and intersections The overall density of the proposed Considerations (together with excessive traffic mixed use areas is envisioned as 5 With I‐70 and US Route 40 being demands) yield traffic delays and to 8 units per acre along with major east‐west arterials that sluggish traffic flow. supporting commercial uses. The traverse downtown Columbus and goal of these areas is to create a serve the overall region via In order to yield a successful Town “village center” environment, interchanges with I‐270, it is only Center development with encouraging development within a logical that development will appropriate access, considerations limited area that could support continue to progress westward should be given to improving and some commercial uses oriented along the US 40/I‐70 corridor. Based enhancing the US 40 corridor. toward the street and create an on the general land use plan, the attractive pedestrian environment. Town Center would have its As the Town Center continues to primary access via a major gateway develop, consideration should also 3.3.5 Agriculture on US 40 and a new interchange on be given to the establishment of a The Accord Plan recognizes that I‐70. Murnan Road could provide new interchange on I‐70. A new farming is an important local and access to the Town Center from interchange will further improve regional industry. Development areas south of US 40 while Feder accessibility for the Town Center patterns, increased traffic, demand Road could link the Town Center and will relieve traffic demands on for higher yield crops and costs with Alton‐Darby Creek Road. Feder and Renner Roads (as they associated with farming have feed the Hilliard‐Rome Road caused many local farmers to sell Based on an initial 5,000 dwelling interchange). This will also reduce their land for development in order units, the Town Center could traffic demands at the Hilliard‐ to realize a return on their generate up to 10,000 work‐related Rome Road interchange and investment. vehicle‐trips during the morning create a more balanced regional and afternoon commuter peak roadway system. Active agriculture uses are hours. With the primary expected to continue within the employment zones being to the As shown on the general land use planning area; agriculture is a north in Hilliard and Dublin, plan, the proposed I‐70 interchange permitted use within the proposed to the east toward downtown would be “one‐sided” and not have conservation development areas. Columbus, and around the I‐270 a roadway extending to the north. Over time, it is anticipated that corridor, the majority of the drivers The intent is to primarily serve the many of today’s active farms will will desire to use Alton & Darby Town Center to the south. transition into conservation Creek Road (and Cosgray Road), However, it is recognized that any development and as a result active I‐70, and US 40. new interchange will provide the agriculture is not a dominating land “opportunity” for drivers to access use on Figure 3.7. As the primary east‐west roadway points to the north. The impact of providing direct access to this travel on the roadway systems The Accord should work with local developments along the US 40/I‐70 to the north of I‐70 will have to be farmers to implement practical best corridor, steps should be taken to carefully evaluated in an management practices to reduce the protect and improve mobility and Interchange Justification Study that impacts that farming practices have traffic flow along US 40 – while at will need to be submitted to ODOT on local water quality. Many the same time balancing this and the Federal Highway existing, local programs, such as regional need with proper access Administration. agriculture easements, can result in for major developments. A tax savings for land owners. In significant portion of US 40 east of

B I G D A R B Y A C C O R D C H A P T E R 3 . 0 ― L A N D U S E P L A N / 3-19 The Interchange Justification Study concepts into development – 3.5 Water Quality will need to address the potential particularly the areas that include for new development within the higher densities that can achieve Water quality considerations of the interchange area. It is common for the goals of LEED ND. land use plan have been addressed intense auto‐oriented development through a hydrological modeling to surround freeway interchanges. The LEED ND rating system is exercise and an assessment of If proper land‐use controls are not divided into “prerequisites” and stormwater management policies in place new development at the “credits”. To achieve a basic LEED and best management applications. new interchange could quickly ND certification, a project must The modeling process and overwhelm the area. The Accord achieve all the prerequisites to outcomes are described in the jurisdictions will need to work achieve a higher certification such following section, followed by a together to ensure that any as silver, gold or platinum, a project discussion of stormwater best development near the interchange needs to achieve a certain amount management practices. Appendix A is consistent with the Accord of the credits. provides a more detailed discussion Plan and proposed Town Center about the modeling process. Master Plan. The categories included in this system are: 3.5.1 Water Quality Modeling 3.4 LEED Principles of Design • Location efficiency which The purpose of water quality addresses the issue of development modeling was to determine the Another key concept that should be (or redevelopment) within the urban impact on water quality, measured incorporated in site design and environment versus development on in terms of pollutant loading, community planning in the Accord Greenfield areas at the edge of the related to proposed land use planning area is outlined by region changes within the planning area. Leadership in Energy and • Environmental preservation which Using the Soil and Water Environmental Design (LEED). includes protection of ecological Assessment Tool (SWAT) software, LEED is a rating framework that communities, sensitive a baseline condition model was has been developed for buildings – environmental areas, and site design created similar to the Generalized also known as the Green Building that supports protection and creation Watershed Loading Functions Rating System. The general land of high quality natural environments. (GWLF) model established by the use plan identifies an area of about • Compact, Complete, and Connected Ohio EPA (OEPA) for the Big 350 acres for residential Neighborhoods which includes Darby Creek TMDL analysis and development that is encouraged to providing for a diversity of uses, report. The SWAT baseline model develop using LEED techniques. creating pedestrian friendly was calibrated for flow to the Many communities and developers environments, and cluster of U.S. Geological Survey (USGS) around the country are adopting development gage along Hellbranch Run; the LEED practices and seeking to have model was then calibrated to the their buildings certified as LEED A goal of the Big Darby Accord EPA’s GWLF model results for rated buildings. Arlington, Virginia should be to integrate the LEED Total Nitrogen (TN), Total for example requires all public ND standards into the day to day Phosphorous (TP), and Total buildings have a goal of achieving a practices making the Accord area Suspended Solids (TSS). silver rating for new buildings. For a leader in Central Ohio for the purposes of a large planning sustainable design. Although the Ohio EPA did not area like Darby Accord, the focus is publish calculated TN loadings in less on individual buildings and the TMDL report, the Ohio EPA more on community and site provided detailed and summary planning. LEED is developing a model results that included those new rating system called LEED ND values for the Hellbranch Run (Neighborhood Design) that watershed and other focuses on elements that bring the subwatersheds that are at least buildings together into a partially within the Big Darby neighborhood and relates a Accord planning area. The final neighborhood to its larger region. It calibration model’s parameters is strongly encouraged that Accord were then used to analyze the jurisdictions incorporate these effects of the land use plan,

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Overland Volume SF/BF Runoff TSS Construction/ Description (mm) Q (cfs) (%) TN (kg) TP (kg) (kg) Channel Erosion TSS (kg)

TMDL Existing NA NA 59/41 NA 16,359 3,051,200 17,594,074

TMDL Allowable NA NA NA NA 3,175 1,086,249 SWAT Baseline model + PS 344.4 39.3 54/46 190,885 15,944 3,439,721 17,594,074 SWAT Final Land Use Scenario model + PS 369.8 42.2 62/38 113,617 4,517 1,023,087 17,594,074

Figure 3.8 Calibration and Final Land Use Model Results PS – Point source loading mm – millimeters cfs – cubic feet per second SF/BF – surface flow / base flow

comparing the pollutant loadings Planning area The results of the calibration predicted by the SWAT model to The modeling planning area is modeling serve as the baseline for the target water quality goals essentially comprised of two large comparison to the final land use published in the Ohio EPA TMDL sub‐watersheds: the Hellbranch plan, described below. This report. The model results were also Run sub‐watershed and all other comparison allowed for a used to evaluate the requirements areas within Franklin County that determination of the changes in for stormwater BMPs, in an effort to are directly tributary to Big Darby pollutant loading related to the mitigate the impact Creek. Each of these sub‐ changes in land use for the of changing land uses and watersheds was divided further planning area. development on pollutant loadings. into 51 sub‐basins to allow for a more detailed analysis. Final Land Use Plan Model Pollutant Loading Considerations The final land use plan model was The pollutant constituents analyzed Calibration Model established from the baseline are those that are commonly The calibration model represents (calibration) model by changing the considered and are most likely to the existing land use condition land use coverage to reflect be affected by changing land use within the planning area. The land projected build‐out conditions. The conditions including TN, TP and use coverage used in the calibration fundamental changes related to the TSS. Heavy metals, especially model was provided by the Ohio final land use plan are described within the Big Darby Accord EPA and is identical to that used in below. planning area, did not appear to be the TMDL analysis. 1. Converting existing agricultural land a significant consideration in the uses to a variety of urbanized land published TMDL. Furthermore, After all data input was completed, uses, varying from a low density there are no anticipated future the SWAT baseline model was (conservation development) industrial land uses or other point calibrated for flow to the USGS residential to a commercial level of source contributors within the gage along Hellbranch Run; the development. planning area that would be a model was then calibrated to the 2. Converting existing agricultural land significant contributor of those EPA’s GWLF model results for TN, uses to preserved open space pollutants. TP and TSS. All calibration (conservation areas). operations were performed using data for the Hellbranch Run sub‐ watershed.

B I G D A R B Y A C C O R D C H A P T E R 3 . 0 ― L A N D U S E P L A N / 3-21 Percent Loading Pollutant Reduction1 that pollutant. The TMDL contains • The analysis performed does not Hellbranch Entire additional information relating the represent the presence of field tile Run Planning additional loading associated with that exists in conjunction with Watershed area2 construction activities and channel agricultural land uses. Eliminating TSS3 70% (95%) 44% bank erosion. Considerations to field tile would likely reduce the TP 72% (81%) 65% reduce these individual change in flow rate and the surface TN 41% (N/A) 40% components include comprehensive flow/baseflow relationship. erosion and sediment control • Stream restoration activities can have Figure 3.9 criteria and incentives to promote a beneficial impact on multiple facets Comparison of Baseline Condition to stream bank stabilization and/or of the modeling provided for this Land Use Plan 1Compared to SWAT Baseline model restoration activities within the study. Stream restoration to add 2Includes areas directly tributary to watershed. floodplain storage can mitigate the Big Darby Creek impact of increased flow associated 3Pertains only to the overland runoff component of TSS It is important to note that the with urbanizing areas and can ( %) – percent reduction prescribed in the results represented by the SWAT increase the assimilative capacity of TMDL; no value published for TN modeling exercise represent and pollutants conveyed within the summarized within Appendix A stream channel, particularly TSS. Conclusions are only an analysis of land use The modeling analysis was changes within the Accord Impervious Surfaces successful in duplicating the results planning area and do not account The percentage of the total from the TMDL study, in particular for stormwater BMP applications or impervious area (PTIA), or the for the Hellbranch Run watershed. specific site planning practices, amount of the watershed covered With that modeling serving as a such as low‐impact design, that by surfaces preventing water baseline for comparison, it has been would further reduce pollutant infiltration, has been found to be determined that the general land loading or increase infiltration from predictive of the amount of stress use plan for the Big Darby Accord urbanizing land uses. Other and degradation to streams. An will ultimately reduce the level of important observations regarding estimate of impervious surfaces for pollutants that are contained in the modeling and the accomp‐ the land use plan at build‐out stormwater runoff and discharged anying results are described below. within the planning area indicates to Hellbranch Run or directly to the • The significant reduction in an increase from approximately 6 % Big Darby Creek main stem. The pollutants when comparing the final (existing conditions) to percent reduction in the various general land use plan to the baseline approximately 10%. pollutants for Hellbranch Run and condition can be attributed to the for the larger planning area is replacement of agriculture with While there is some degree of shown in Figure 3.10. As expected, urbanizing land uses and the variability for threshold PTIA the increase in impervious area representation of conservation open levels, ranging between 5% and associated with the urbanizing land space that replaces a considerable 15% according to various studies, uses contained within the land use amount of land currently being used the goal of 10% is a commonly plan will increase the calculated for agriculture. identified threshold for many average annual flow rate and cause a re‐distribution of the surface Researchers State PTIA Threshold flow/baseflow relationship within the planning area. C. May (1997) Washington 5-10% R.D. Klein (1979) Maryland 10% The percent reductions noted in E.J. Shaver, G.C. Maxted, D. Carter (1995) Delaware 8-15% Figure 3.9 for the Hellbranch Run watershed are less than those T.R. Schueler & A. Gali (1992) Maryland 15% specified in the TMDL to obtain the G.C. Maxted (1996) Delaware 10-15% target levels for those pollutants (Note: TN is not presented in the R.C. Jones & C.C. Clark Virginia 15-25% TMDL). Furthermore, the Figure 3.10 Percent Total Impervious Area (PTIA) Variability comparison of TSS only pertains to Source: Schueler, T.R. 1994. The importance of Imperviousness, the overland runoff component of Watershed Protection Techniques 1 (3): 100-111.

3-22 / C H A P T E R 3 . 0 ― L A N D U S E P L A N B I G D A R B Y A C C O R D watersheds within the United Structural BMPs are constructed of the stream channel, water quality States (Figure 3.10). It is also features often included with or and habitat, increased channel important to understand that adjacent to a development site that erosion and overbank flooding. The ‘imperviousness’ is merely an receive, capture and provide some core principle of low‐impact indicator of various cumulative mitigating treatment for development is the planning and hydrological impacts to the waters stormwater volume and pollutant design of development projects that and is not by‐itself the cause of constituency associated with runoff have a reduced impact on degradation. This concept is from that site. Non‐structural BMPs watersheds, accomplished through important within the context of the are best represented by low‐impact the basic principles listed below. Darby Accord Plan which development techniques that are 1. Reducing the amount of impervious emphasizes best management reflected in how a development site cover within proposed developments. practices and low‐impact is planned to reduce the amount of 2. Increasing the natural land set aside development to minimize effects of impervious surface and/or the for conservation. development with a comprehensive connection between impervious 3. Using pervious areas for more multi‐strategy approach. The areas. The application of these effective stormwater treatment. Appendix provides a more different approaches to the site detailed analysis of water quality development process may depend These practices, recommended for modeling efforts. on the type and density of stormwater and stream protection development permitted by the land by the Hellbranch Watershed 3.5.2 Stormwater Management use zoning. Forum, result in the conservation of Stormwater management involves natural features and resources, managing the volume, the intensity The Ohio EPA has released a draft reduction in impervious surfaces and the quality of stormwater permit for the Big Darby Creek for roadway and parking lot areas, discharges into receiving waters. watershed (Ohio EPA Permit No. concentration of development in Changes in land use and OHC100001) related to water less sensitive areas and the use of development can alter both the quality controls to be used during natural areas for stormwater quality and quantity of stormwater construction, titled Authorization for management. Better site design runoff. To meet the water quality Storm Water Discharges Associated practices address both water goals of the TMDL, application of a with Construction Activity Located quality and quantity management comprehensive stormwater Within the Big Darby Creek Watershed from developments. The practices management program will be Under the National Pollutant result in a more natural and cost required, incorporating various Discharge Elimination System. The effective stormwater management aspects of both structural and non‐ draft NPDES permit details the system that reflects the natural structural BMPs. measures that developers must hydrologic conditions of the site implement to control runoff during and can reduce long term In areas undergoing new construction activities and provides maintenance. development, such as the Accord criteria for post‐construction water planning area, the most effective quality. Along with the guidelines A previous stakeholder initiative, methods of controlling impacts of the Ohio EPA permit, several referred to as Central Ohio from stormwater discharge are to strategies have been identified to Regional Forum Darby Watershed limit the amount of rainfall that is address water quality related to Advisory Group, developed converted to runoff and to capture development in the watershed. twenty‐two model development and treat the runoff that is Policies related to stormwater principles related to land use generated. By utilizing structural management are further described development and best management and non‐structural techniques for in Section 4.0 practices that are applicable to the achieving these goals, site Accord process. These model development activities can be Low‐Impact Development development principles can be planned and designed in such a Increased development typically found in the document entitled manner that the impacts on the brings increased stormwater runoff Darby Creek Watershed Stormwater watershed associated with volumes in conjunction with an Management Strategies and Standards development can be mitigated. increased pollutant load from the for New Development, 2001. Many of runoff. The increased quantity of the principles relate to site design stormwater and the associated recommendations to minimize pollutants can lead to degradation stormwater impacts while others

B I G D A R B Y A C C O R D C H A P T E R 3 . 0 ― L A N D U S E P L A N / 3-23 are more closely tied to treatment surfaces and shared drives that Stormwater Management Strategies mechanisms. Those that directly connect to two or more homes and Standards, 2001). reference BMPs (not including site together (Principle 13, Darby Creek ƒ Enclosing, straightening, and design principles) have been listed Watershed Stormwater Management relocating streams should be below. In addition, principles Strategies and Standards, 2001). discouraged during all new adapted from the document ƒ Direct rooftop runoff to pervious development (Principle 22, Darby entitled EPA National Management areas such as yards, open channels, or Creek Watershed Stormwater Measure to Control Nonpoint Source vegetated areas and avoid routing Management Strategies and Pollution from Urban Areas, 2002, rooftop runoff to the roadway and Standards, 2001). provide a solid foundation for the stormwater conveyance system ƒ Clearly specify how community open future development policies (Principle 15, Darby Creek Watershed space will be managed and designate regarding BMPs; these have also Stormwater Management Strategies a sustainable legal entity responsible been included below. Together and Standards, 2001). for managing natural, recreational, these principles provide a solid ƒ Create a variable width, naturally and stormwater management open foundation to begin considering a vegetated buffer system along all space (Principle 14, Darby Creek BMP toolkit suitable for the Darby perennial streams that also Watershed Stormwater Management watershed that will provide a level encompasses critical environmental Strategies and Standards, 2001). of protection that promotes features such as the 100 year ƒ Incentives and flexibility in the form watershed stability. floodplain, steep slopes and of density compensation, buffer ƒ Incorporate landscaped areas with freshwater wetlands (Principle 16, averaging, property tax reduction, cul‐de‐sacs to reduce impervious Darby Creek Watershed Stormwater stormwater credits, and by‐right open cover and provide stormwater Management Strategies and space development should be treatment (Principle 4, Darby Creek Standards, 2001). encouraged to promote conservation Watershed Stormwater Management ƒ The riparian stream buffer should be of stream buffers, forests, meadows, Strategies and Standards, 2001). preserved or restored with native and other areas of environmental ƒ Where density, topography, soils and vegetation that can be maintained value. Off‐site mitigation for open slope permit, vegetated open throughout the plan review, space, stormwater management and channels should be used in the street delineation, construction, and forest resources (excluding riparian right‐of‐way to convey and treat occupancy stages of development buffers) within the same watershed stormwater runoff (Principle 5, Darby (Principle 17, Darby Creek Watershed should be encouraged (Principle 20, Creek Watershed Stormwater Stormwater Management Strategies Darby Creek Watershed Stormwater Management Strategies and and Standards, 2001). Management Strategies and Standards, 2001). ƒ Clearing and grading of forests and Standards, 2001). ƒ Advocate open space development native vegetation at a site should be ƒ Maintain predevelopment site that incorporates smaller lot sizes to limited to the minimum amount hydrology by using site design minimize total impervious area, needed to build lots, allow access and techniques that store, infiltrate, reduce total construction costs, provide fire protection. A fixed evaporate, or detain runoff (EPA conserve natural areas, provide portion of any community open space National Management Measure to community recreational space, and should be managed as protected Control Nonpoint Source Pollution promote watershed protection green space in a consolidated manner from Urban Areas, 2002). (Principle 10, Darby Creek Watershed (Principle 18, Darby Creek Watershed ƒ Use natural hydrology as a design Stormwater Management Strategies Stormwater Management Strategies element and avoid alteration, and Standards, 2001). and Standards, 2001). modification, or destruction of ƒ Wherever possible, provide ƒ Conserve trees and other vegetation natural drainage features (EPA stormwater treatment for parking lot at each site by planting additional National Management Measure to runoff using bioretention areas, filter vegetation, clustering tree areas, and Control Nonpoint Source Pollution strips and/or other practices that can promoting the use of native plants from Urban Areas, 2002). be integrated into required (Principle 19, Darby Creek Watershed ƒ Protect areas that provide important landscaping areas and traffic islands Stormwater Management Strategies water quality benefits, habitat areas (Principle 9, Darby Creek Watershed and Standards, 2001). or are particularly susceptible to Stormwater Management Strategies ƒ New development should not degradation (EPA National and Standards, 2001). discharge unmanaged stormwater Management Measure to Control ƒ Reduce overall lot imperviousness by (Principle 21, Darby Creek Watershed Nonpoint Source Pollution from promoting alternative driveway Urban Areas, 2002).

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ƒ Site plan review and conditional where development will have strips that can be dispersed approval should address and ensure minimal impact on hydrology and throughout a site. that the integrity of environmentally other sensitive features of the site sensitive areas and areas necessary and surrounding area. Reducing A variety of techniques can be used for maintaining natural hydrology the overall development envelope in low impact development, and water quality will not be lost allows for a larger portion of allowing for customization (EPA National Management Measure stormwater to seep into soils according to local codes and to Control Nonpoint Source Pollution gradually, removing contaminants, management requirements, site from Urban Areas, 2002). replenishing soil moisture, and constraints and opportunities and ƒ Limit land disturbance activities, such recharging the shallow topographic and climate conditions. as clearing and grading and cut‐and‐ groundwater condition naturally Although low impact development fill, to reduce erosion and sediment without piping infrastructure techniques have become more loss and limit disturbance of natural leading to a centralized end of pipe common recently, codes and drainage features and vegetation approach to stormwater treatment. regulations may be outdated and during site development (EPA may not allow for such practices. National Management Measure to Once site characteristics are Zoning bylaws, site plan review, Control Nonpoint Source Pollution inventoried, potential site subdivision rules and regulations, from Urban Areas, 2002). development layouts can be wetland regulations and building ƒ Protect and retain existing vegetation configured. Site layouts should be codes should all be revisited. Some to help control erosion (EPA National designed to minimize impervious of the more prevalent site design Management Measure to Control areas, retain natural topography techniques include (Whole Building Nonpoint Source Pollution from and use existing natural Design Center): Urban Areas, 2002). drainageways, swales, depressions • Minimizing imperviousness with ƒ Minimize imperviousness to the and storage areas, ultimately permeable paving or landscaping extent practicable (EPA National minimizing the volume of runoff to break up expanses of impervious Management Measure to Control that must be treated in a surfaces; Nonpoint Source Pollution from stormwater management system. • Directing runoff into or across Urban Areas, 2002). Methods that will help reduce site vegetated areas to filter runoff and ƒ Incorporate open space and natural coverage include clustering encourage groundwater recharge; areas into site designs with an development, increasing building • Preserving or enhancing natural emphasis on creating an heights (within the allowable vegetation near parking areas, interconnected green infrastructure zoning regulations), building buildings, and other impervious that has positive benefits to water parking structures instead of lots, expanses in order to slow runoff, quality and quality of life (EPA reducing road widths and using filter out pollutants, and facilitate National Management Measure to permeable paving and green roofs. infiltration; Control Nonpoint Source Pollution • Reducing street and sidewalk from Urban Areas, 2002). Conventional stormwater treatment widths where appropriate; systems use a piped system leading • Removing curbs and gutters from Approach to LID Site Design to a central stormwater treatment streets, parking areas, and parking LID site design should begin with center. Low impact development islands to allow storm water sheet an inventory of existing site takes advantage of a decentralized flow into vegetated areas; conditions and natural features of stormwater system that is • Using devices such as bioretention the site to determine protection integrated into site design for both cells, vegetated swales, green roofs, areas as well as what natural the function of treating water and infiltration trenches, and dry wells features can be incorporated into as a landscape amenity. The goal of to increase storage volume and the LID stormwater management a low impact system is to increase facilitate infiltration; system. An inventory of natural the time of concentration through • Installing vegetated roofs or garden features would likely include stormwater retention close to the roofs; streams, floodplains, wetlands, source, open drainage systems • Grading the site to encourage sheet groundwater recharge protection (vegetated swales and filter strips), flow and lengthen flow paths to areas, soil characteristics, slopes long drainage paths and vegetated increase the runoff travel time in and conservation areas. The paths. Decentralized structures may order to modify the peak flow rate; inventory will reveal the overall include swales, bioretention areas, • Disconnecting impervious areas development envelope, defining infiltration structures, and filter from the storm drain network and

B I G D A R B Y A C C O R D C H A P T E R 3 . 0 ― L A N D U S E P L A N / 3-25 maintaining natural drainage residential development, reducing Structural BMP Applications divides to keep flow paths associated stormwater runoff and Stormwater runoff generated from dispersed; pollutant load levels. Many proposed development areas must • Disconnecting roof downspouts residential streets can accommodate be controlled before it is released and directing storm water into two travel lanes and two parking from the development site. vegetated areas or water collection lanes. Streets can be narrowed Stormwater controls will address devices; without sacrificing emergency both the quantity and quality of • Installing cisterns or sub‐surface access, on street parking or stormwater discharge from a retention facilities to capture vehicular safety. The applicability development site in order to rainwater for use in irrigation and of requiring narrower residential maintain and/or improve the non‐potable uses; streets may be dependent on the quality of the streams and receiving • Using native plants (or adaptable development size. According to the waters within the planning area. species) to establish an adaptable Stormwater Manager’s Resource and low maintenance landscape Center, narrower streets can be For new development that occurs that requires less irrigation and are used in residential developments within the planning area, the appropriate for the climatic settings that generate 500 or less application of structural BMPs will conditions; average daily trips (ADT) be an integral component of • Using naturally occurring bio‐ (generally about 50 single family meeting the water quality goals of chemical processes in plants homes) and may sometimes also be the TMDL. The various aspects of located in tree box filters, swales, feasible for streets that are projected structural BMPs associated with planter boxes. to have 500 to 1,000 ADT. Reducing site development can be road widths may not be suitable for distinguished within the categories Minimize Impervious Surfaces roadways that carry greater described below. Although roads are a basic volumes of traffic or are not • Stormwater quantity control – the component of any development, expected to have a constant traffic application of stormwater detention minimizing the overall road volume over time. Implementation facilities to address the increase in the network coverage can serve as a of narrowed road widths may volume and peak rate of flow significant component to require a revision to local road associated with runoff from a implementing low impact standards and zoning codes. development site. development practices. Streets • Groundwater recharge – the comprise the largest share (40 to When laying out new roads, application of infiltration practices to 50%) of impervious cover in consideration should be given to reduce the amount of surface runoff residential developments. existing natural drainage patterns, that is discharged from a Narrower streets can result in an sensitive areas and surface waters. development site and increase the impervious cover reduction of 5 to Road design should give contributions to groundwater that 20% for a typical residential consideration to natural features sustains stream baseflow. subdivision (Schueler, 1995). and post development conditions, • Stormwater water quality – the Residential streets rank as a major including topography, natural application of stormwater features source area for many stormwater drainage patterns, soils, climate, that capture and may also treat pollutants, including sediment, existing land use, estimated traffic pollutants captured within bacteria, nutrients, hydrocarbons volume and sensitive land areas. stormwater runoff. This approach and metals (Steur; Bannerman). The These factors all influence the applies to both construction and majority of pollutants deposited on impacts of nonpoint source post‐construction phases of a or along street surfaces gets washed pollution, erosion and sediment development site. up during storm events into the problems. Consideration for these storm drainage system. natural features can greatly An increase in development and Reduction of impervious surfaces minimize erosion and the associated impervious surfaces allows for increased natural sedimentation and prevent NPS increases the volume of runoff from filtration and less stormwater pollutants from entering a development site and can, runoff and pollutant loadings. watercourses during and after therefore, increase the quantity of construction. physical and chemical substances Promoting the use of narrower that have a detrimental impact on streets will reduce the amount of the water quality of the receiving impervious cover created by stream. The primary pollutants of

3-26 / C H A P T E R 3 . 0 ― L A N D U S E P L A N B I G D A R B Y A C C O R D concern within the planning area, erosion control than sediment to the impairment of streams identified in the TMDL, are TSS, settling basins. The EAG including Clover Groff, Hamilton TN and TP. All three of these recommends the use of sediment and Hellbranch Run and pollutants have the potential to control ponds for all development retrofitting existing development impact the aquatic health of the sites, regardless of size. The current to address impacts may be streams. Excess sediment within statewide NPDES permit (and the beneficial and necessary to meet stormwater runoff can limit the draft permit for the Big Darby water quality goals. areas in which certain species will Creek watershed) require that locate, and can create many other sediment basins be constructed for The approach to developing within problems. Nitrogen and areas that receive drainage from the Big Darby Creek Watershed phosphorous can lead to excessive disturbed areas of 5 acres or will need to consider the unique algal growth, and a reduction in the greater. At a minimum, the environmental constraints and available oxygen within a stream. requirements of the Ohio EPA’s incorporate elements of good As development occurs, there are permit must be followed within the design and sustainability to ensure two distinct periods of time where Accord planning area, allowing for protection of important natural and the control of water quality the use of silt fences and other biological resources, including parameters must be considered: erosion control BMPs to control water quality. Best management during construction and post‐ sediment from sites less than 5 practices that incorporate construction. Construction related acres in size. innovative technologies are one water quality controls must mechanism available to assist with primarily address the excess The draft NPDES permit for the this effort. Best management sediment that is present during Big Darby Creek watershed practices are typically intended to construction activities, but are contains a target discharge of 45 control non‐point source pollution temporary in nature. By contrast, mg/l TSS for up to a 0.75 inch on a development‐site scale; post development water quality rainfall in 24 hours that must be however, their application can have controls must be able to control met for land area disturbances and positive watershed‐wide impacts multiple pollutants over a long is measured at the outfall of a and can be applied to individual period of time. Considerations sediment settling basin. The property owners, neighborhoods for both types of control are permit also requires the outfalls of and municipalities. presented below. such ponds be monitored initially and then quarterly Principles of Mitigating Water Construction Phase through the project duration to Quality Impacts Stormwater Control insure compliance with the Information within this section is The control measures included in targeted sediment discharge limit derived from the Northern Virginia the construction phase of from the basins. Best Management Practices development address runoff and Handbook, prepared in 1992 by the sediment control. More information regarding Northern Virginia Regional acceptable practices for both runoff Planning Commission and Runoff control measures are and sediment control is contained Engineers Surveyors Institute. The applied to prevent or minimize the within ODNR’s Rainwater and Land Northern Virginia BMP Handbook, occurrence of erosion from Development Manual. which is a regionalized update of disturbed areas. Acceptable BMPs the nationally acclaimed BMP recommended for use by the draft Post‐Construction Handbook for the Occoquan NPDES permit for the Big Darby Stormwater Control Watershed, is intended for use by Creek Watershed include rock The unique sensitivity of the designers and reviewers of urban check dams, pipe slope drains, Darby watershed and particularly BMPs in meeting the water quality diversion around exposed areas the Big Darby Accord planning requirements and reflects initiatives and protective grading practices. area will require the application of related to improving water quality techniques to ensure that the within the larger Chesapeake Bay Erosion control measures are watershed is protected and that watershed. applied to abate the release of impacts of new development eroded sediment from a disturbed are minimized. Existing The basic mechanisms of pollutant area. Applications such as silt fence development and agricultural removal operating in BMP facilities are significantly less effective at practices are already contributing are the gravitational settling of

B I G D A R B Y A C C O R D C H A P T E R 3 . 0 ― L A N D U S E P L A N / 3-27 pollutants, infiltration of soluble nutrients in wetlands and BMP 3.5.3 Performance Goals nutrients through the soil profile facilities. The TMDL report for the Big Darby and, to a lesser extent, biological Creek defines the maximum and chemical stabilization of Soil Infiltration loading for pollutants of concern nutrients, discussed below. Infiltration is usually achieved by within the Accord planning area to Extended detention stormwater lining a trench with a stone meet the objectives of water quality basins utilize settling as the aggregate and a surrounding filter within the watershed. To achieve primary removal process, with fabric to act as a filter medium and these maximum loadings values, some nutrient uptake by the to remove much of the suspended the TMDL defines a percent vegetative cover and soils. Wet sediments and attached removal for each of those pollutants ponds utilize settling as their contaminants before entering the from the existing conditions within principle removal method as well, soil horizon. Subsequent passage of the watershed. Within the but the existence of a permanent water through the underlying soil Hellbranch Run watershed, the pool also promotes biological and column provides further filtering total allowable TSS load is 1,086,000 chemical uptake and some and pollutant removal through kilograms per year, which is a 95% infiltration through the soil aerobic decomposition and reduction from the TSS load horizon. Infiltration trenches rely chemical precipitation. reaching the stream under existing heavily on filtration through the conditions. Based on this soil profile for pollutant removal An important concern which arises information, the stormwater BMPs with some biological and chemical from the infiltration process is the that will be utilized within the stabilization of pollutants. potential infiltration of polluted planning area will have to meet the stormwater through the soil removal requirements of the Settling column to the water table. In some TMDL. Additional information The establishment of a temporary instances this could add regarding BMPs and their ability to or permanent pool of water, as is contaminants to the underlying remove pollutants from stormwater utilized in both extended detention aquifer system. This is of special runoff is presented in Section 4. dry and wet ponds, results in concern if the aquifer is to be used conditions which can settle out as a potable water supply in nearby It should be noted that discussions particulate pollutants between areas. In addition, the contribution involving representatives of The storms. The particulate materials of nutrients to groundwater may Ohio State University, Ohio EPA, settle into the pond bottom affect local streams whose baseflow the Ohio Department of Natural sediments while some of the derives significantly from Resources (ODNR) and other soluble pollutants may pass groundwater, thereby re‐ parties are on‐going regarding the through the sediment to the soil introducing nutrients into the most appropriate measure of a profile below by means of surface water that the BMP was performance goal that would meet infiltration. designed to protect. the objectives for water quality suggested by the TMDL. These Biological and Chemical Processes Where soils are appropriate, discussions are contemplating a Removal of soluble pollutants is infiltration provides substantial numerical pollutant loading value accomplished primarily through hydrologic benefits. Structural (or concentration) requirement for the mechanisms of chemical and practices treat runoff, but more is release from a development site biological stabilization of nutrients. needed to effectively prevent and rather than a percent removal The biological activities of some minimize impacts. Therefore efficiency as currently defined in species of plants, algae and other additional management practices the TMDL. The numerical load aquatic organisms can serve as a are strongly encouraged such as number would allow developers to mechanism for removing soluble stream setbacks or reduction of calculate an absolute pollutant load nutrients from the water column. impervious areas that influence the value, likely in milligrams per liter, Dissolved oxygen levels, layout and design of a development which the development site could temperature, sunlight and pH affect site so that important hydrologic discharge to the receiving stream or the biological stabilization of a areas are maintained and downstream system. pond. The underlying soil has also impervious surfaces are limited. been identified as contributing to (ODNR) chemical transformation of

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Water Quality Volume BMP Pilot Study impairments in these areas. A The pollutants of concern within A study of the application of concept for “controlled drainage” the planning area are largely settle‐ various BMPs within a portion of has also been developed and able pollutants in that, if the the planning area was conducted to promoted by individuals affiliated velocity of the stormwater runoff is establish a scenario wherein the with The Ohio State University. decreased to nearly zero, then the specified goals of the TMDL could This unique application utilizes pollutants will settle out of the be met. A summary report of that control structures placed on‐line water column. This is true not only effort is provided in Appendix A. with existing field tiles to create a of the TSS components in mechanism for manipulating the stormwater runoff, but other Addressing Developed Areas ground water table within a pollutants that bind themselves to Many areas in the eastern portion agricultural field. The application the solids and can then be captured of the planning area are already promotes a higher groundwater through the settling process. Much developed, especially in areas along table during the growing season of the pollution potential within a Clover Groff and Hamilton Runs as when fertilizer and pesticide watershed comes from the most well as Hellbranch Run. Similarly, applications are most prevalent and frequent rain events, which has these same areas are associated impedes the release of the residual been found to correlate to with declining water quality. As components of those chemicals to approximately the initial 0.75 parts of the watershed develop, it the receiving stream. inches of rainfall, often referred to will be equally important to as the “first flush” of stormwater identify ways to improve the A major consideration will be the runoff. The water quality volume is, conditions along these corridors. willingness of property owners, therefore, that volume of water that Developing areas typically provide and the amount of adequate space is generated from a site during a considerably more opportunities to and condition of the area. The 0.75 inch rainfall event. If the water incorporate quantifiable land use‐ identification of potential retrofit quality volume is then captured based and control‐based structural sites should be developed in within the limits of a development and nonstructural BMPs. Once a cooperation with ODNR, Metro site for a certain period of time landscape is firmly established, Parks, the local agricultural (usually varying from 24 to 48 room may not exist to implement community and other key agencies hours) it is assumed that a large these techniques, or public reaction that are already actively pursuing percentage of the pollutants of to change may prevent their efforts in the watershed to improve concern would be removed by the implementation. In general, public water quality. Multi‐agency settling action that occurs during education‐style pollution pursuits often have added weight this time period. prevention measures are the most when it comes to funding priorities. applicable for “retrofitting” existing The Ohio EPA has recognized the areas since they require no physical 3.6 Stream Restoration benefit that can be obtained by change in the landscape. However, requiring a water quality volume these programs often do not result The TMDL for the Big Darby Creek draw‐down time (the amount of in quantifiable results. Street watershed and other related Ohio time it takes for the water quality sweeping, as a control technique, is EPA publications identify areas of volume to be discharged from a also highly applicable to existing impairment along the major development site), and within their urban areas and is often desirable watercourses within the planning draft permit include an equation to for its positive aesthetic impact on area. The impairment constitutes a determine the actual water quality the urban environment. physical degradation of the stream volume for a development site. In channels that has led to a low or addition to the water quality In agricultural areas, techniques to non‐attainment of aquatic life use volume calculation for all sites, the address water quality are also very within the channel. Based on those Ohio EPA includes draw‐down important. Non‐structural BMPs findings, it is clear that the areas of times that are different for several are more often associated with highest degradation are along the different types of stormwater BMP retrofitting an agricultural land use. upper reaches of the Hellbranch applications. Promoting stream setbacks as Run watershed, associated with riparian corridors and filter strips Clover Groff and Hamilton Runs. are the most obvious and The TMDL cites the conditions prominent techniques for associated with an urbanizing addressing water quality

B I G D A R B Y A C C O R D C H A P T E R 3 . 0 ― L A N D U S E P L A N / 3-29 watershed, as it impacts Clover condition. The resulting instability Although not the focus of any Groff Run and is conveyed to often leads to a higher rate of channel previous studies, there are Hellbranch Run. Other than the bank erosion that contributes more numerous smaller tributary sediment loading to the stream consequences of an urbanizing watercourses that discharge system. The incised channel also watershed, the most obvious directly to the Big Darby Creek loses the ability to utilize the component of impairment within floodplain for deposition of sediment main stem. Observances of some of both of these channels is that they and the other storage and filtering those stream channels suggest that have been hydromodified through properties that could contribute to they are also beginning to or are the ditching process. The ditching enhanced water quality. susceptible to degradation, due to process constitutes a widening and • A stream channel with an impaired either their position in the deepening of the channel and is riparian buffer corridor loses a landscape (steep gradient) or significant habitat attribute. The loss most commonly associated with the because of adjoining land uses. of the buffer removes a feature that drainage of adjoining agricultural Development within these smaller provides several attributes. A fields. As an additional form of vegetative corridor provides stability watershed areas can have an even impairment, the riparian buffers to channel banks while also more immediate impact to stream along both Clover Groff and enhancing the aquatic environment. channel stability that would not Hamilton Runs have been only impact the tributary channel encroached upon by the practices of The findings of the TMDL are but also contribute sediment the adjoining urban and consistent in terms of the type and loading directly to Big Darby agricultural land uses. nature of the impairments to the Creek. stream channels within the A stream channel that has Hellbranch Run Watershed. The 3.6.1 Hellbranch Run Watershed undergone the ditching process will TMDL indicates a large amount of Restoration Opportunities most likely suffer from the the observed TSS within the The Hellbranch Run Watershed significant impairments described watershed is attributed to channel Forum (HWF) conducted an below. In each case, it would take bank erosion. Other collected extensive investigation of some physical correction to the information reveals a lower habitat restoration opportunities within the channel morphology and/or value within segments of the watershed, intending to identify a adjoining buffer area to reverse the channel system. These observations specific project to implement in condition of impairment. suggest that the conditions cooperation with the U.S. Army described above are associated with Corp of Engineers under their • A stream channel that is over‐deep hydromodified stream channels, a Section 206 Ecosystem Restoration and over‐side has a shallow gradient leading cause of the degradation Program. Based on a specific and (slope) that reduces the ability of the affecting the watershed. Based on detailed evaluation process, the channel to convey bedload materials the degree of degradation that has HWF has identified a stream that are a component of habitat been documented for both Clover restoration project in the vicinity of within the stream. Low gradient streams are often characterized by a Groff and Hamilton Runs, and the confluences of Hamilton, Clover condition of aggradation, where along the upper portions of Groff and Hellbranch Runs. Further sediment runoff from within the Hellbranch Run, it seems unlikely details regarding the nature and watershed accumulates within the that significant ecological benefit extent of the project and the channel, smothering substrate can be obtained by simply program for implementation will be material and filling pools that are a preserving those channels in their developed by the HWF. source of habitat to the macro present conditions. In this case, invertebrate and fish community, stream morphology must be The Accord general land use plan part of the overall ecosystem within a stream. enhanced through some level of indicates a priority stream restoration to sustain a more restoration zone for the entirety of The channel is often further impaired desirable aquatic life use the Clover Groff and Hamilton by the fact that it is now incised, designation and to provide a Runs. The degradation aspects meaning that it is disconnected from meaningful contribution to the noted previously are pervasive the natural floodplain. This overall water quality within the throughout this area. Meaningful disconnection leads to a condition watershed. restoration of these watercourses where the channel now is required to will likely require extensive carry a flow volume in excess of that associated with a stable channel physical alteration of the existing

3-30 / C H A P T E R 3 . 0 ― L A N D U S E P L A N B I G D A R B Y A C C O R D stream channels to provide for the appropriate morphology and habitat features, described later in this section. In identifying restoration opportunities within this watershed, the following should be considered. • Available land area along the stream corridor. The width of the corridor needed to accomplish the restoration Figure 3.11 Over-wide Channel Design Source: Attachment B, Ohio EPA Permit No.: OHC100 can depend on the restoration technique and should account for an adequate buffer area to allow for the the stream channels referenced Over‐wide Channel Technique vegetative corridor that is vital to the within the Hellbranch Run The over‐wide channel technique is restoration goal. At a minimum, the watershed. one that is often described by width of that corridor should be the ODNR and has been developed as a setback calculated in accordance with 3.6.3 Stream Restoration concept specific to headwater the criteria for the Stream Corridor Techniques streams that may develop a Protection Zone (SCPZ), discussed in The approach to stream restoration different ecosystem than expected more detail in Section 4.0. • Position of the project along the depends on the objectives and goals in a typical stream system. The watercourse. From the standpoint of that are being sought related to the technique is defined by the stream ecology, there is an added ecosystem. The two approaches excavation of the overbank area benefit to the restoration project if described below have different along an incised (over‐deep) there is some connectivity to other value in relationship to benefiting channel to bring the elevation of the areas of the watercourse where there the aquatic life use attainment and floodplain down to or nearly to the is a sustained aquatic habitat water quality. The cost of stream flowline of the existing channel. condition. Considering this aspect, restoration can vary depending on The excavated floodplain is initial stream restoration activities should focus on areas in the lower the technique applied; however, expected to be no less than 5 times portions of the both Clover Groff and either approach can incur a and maybe up to 10 times as wide Hamilton Runs to gain the benefit of significant cost. The majority of the as a stable channel width for that the connectivity to portions of costs are related to land acquisition, stream. The result of the Hellbranch Run that have achieved a design and construction. It is application of this technique is a higher aquatic life use designation. foreseeable that stream restoration valley that continues to have the on a large scale can only occur if shallow gradient (slope) of the 3.6.2 Other Restoration financial resources from a variety of impaired stream channel, as that is Opportunities sources are pooled together. not adjusted through the For the portion of the planning area restoration process. that is directly tributary to the Big Darby Creek main stem, there is no specific priority for stream restoration. Opportunities should be identified in conjunction with development activities as they occur within the smaller watershed areas. Because of the small nature of these tributary channels, restoration should focus on channel stability to account for the changing watershed hydrology that may result from the pending development activities. Aquatic habitat use should also be enhanced but that consideration is on a Application of over-wide channel technique. different level of magnitude than Source: EMH&T

B I G D A R B Y A C C O R D C H A P T E R 3 . 0 ― L A N D U S E P L A N / 3-31 The primary function of this Natural Stream Channel relies on stable stream restoration technique may be that it Design Technique geomorphology and the success of is now capable of assimilating a Natural stream channel design macro invertebrates and fish, will significant load of sediment follows the principles of more likely be met. A stream transported through the stream conventional geomorphology, channel with the attributes system. The accumulation of which identifies a fairly distinct described above is more likely to be sediment within the over‐wide structure related to a functional and a feature that is appreciated by the channel is expected, reducing the stable stream structure. The Ohio community and integrated as a loading further downstream in the EPA’s Qualitative Habitat passive recreational attribute. system, and can lead to the Evaluation Index (QHEI) is based formation of a stable channel on the physical components of a Drawbacks feature though the natural process channel that are consistent with this The complexity of design and of aggradation. Alternatively, technique. Essentially, this construction may lead to higher portions of the excavated valley can technique includes channel features overall project costs when take on the qualities of a wetland such as functional pool (deeper compared to other techniques. Due environment, due to the connection water areas) and riffles (high‐ to the likely alteration of stream to groundwater and stream energy grade control features) and flow line elevation and gradient, it baseflow. The wetland a substrate material consistent with is often not possible to apply this environment, although not the bedload capacity of the stream. technique unless it is over a longer conducive to aquatic habitat All of these features are conducive contiguous reach of channel, which conditions, can provide water to both macro invertebrate and fish would require that it be quality benefits through the capture habitat expected to achieve a accomplished only as part of a of sediments and the capture and certain aquatic life use designation. large‐scale project. treatment of nutrients that are processed by the evolving The application of natural channel Stream Naturalization vegetative community. design requires the determination The concept of stream of stable channel geometry through naturalization is discussed in an Benefits the collection of data from an article published in Environmental A simple design process that is also existing stable channel reach and Management, Volume 24, No.3, not complicated to construct. Since the application of empirical design entitled “Interaction Between the flowline of the existing channel methods. Applied to channels Scientists and Nonscientists in is not affected, this technique can within the Hellbranch Run Community‐Based Watershed either be applied on a large‐scale or watershed, this technique would Management: Emergence of the on a localized level. Water quality likely involve both the excavation Concept of Stream Naturalization”. attributes are likely to occur related of the overbank area to establish the From that article, it is stated “that to the assimilation of TSS, TN and stable channel geometry and re‐ the goal of naturalization is to drive TP within the stream system. connect that channel to the the (stream) system as a whole floodplain, and the placement of in‐ toward a state of increasing Drawbacks stream material to accomplish the morphological, hydraulic and The resulting ecosystem within the pool‐riffle complex and to alter the ecological diversity, but to do so in stream channel may not facilitate gradient of the stream channel. a manner that is acceptable to the the aquatic life use designations Furthermore, the pattern of the local community and sustainable by promoted by the Ohio EPA. There stream channel would be altered to natural processes, including human is some uncertainty regarding the be less linear and have the intervention”. This approach to formation of either a channel or characteristics of a meandering stream restoration is derived from functional wetland, which will be stream. the premise that restoration affected by the nature of pollutants activities should consider both the being conveyed in the stream Benefits social and ecological consequences system and the watershed A functional natural stream channel of that activity. The social hydrology. design will be more likely to attain consequences are related to the the aquatic life use designations perceptions of the residents of the promoted by the Ohio EPA. The watershed regarding the purpose measure of a healthy stream, which and value of the watercourses,

3-32 / C H A P T E R 3 . 0 ― L A N D U S E P L A N B I G D A R B Y A C C O R D particularly those who rely on them along Clover Groff and Hamilton Benefits for agricultural drainage or flood Runs and the mix of land uses As with the over‐wide channel control. anticipated within the watershed, it technique, this stream restoration is reasonable to assume that the approach can involve a simple Stream naturalization includes passive recovery of those channels design and construction process, natural stream channel design but will require an extended period of reducing costs associated with allows for a departure from that time, likely decades, and that the those activities. A stable bankfull approach, recognizing the final outcome will be unpredictable. channel dimension must be fundamental limitations described Conceivably, they may never fully determined, but the other below. The factors listed below are recover. To address these morphological parameters not intended to discount the shortcomings and accelerate the associated with natural channel growing and evolving body of naturalization process, a variety of design are not associated with this knowledge and practice related to physical modifications that approach. Assuming the flow line stream restoration using natural essentially de‐channelize the stream elevation and gradient of the channel design. In recent years, can be performed. The channel will not be altered, the considerable knowledge has been predominant modification is to stream naturalization process can gained by the collective interests reestablish the stable bankfull be applied to shorter as well as an who continue to draw from condition and create an adequate extended reaches of a watercourse. experience and apply new solutions connected floodplain to toward finding a correct balance accommodate the dynamic Drawbacks that supports sustainable designs. condition that would allow for the Similar to the over‐wide channel • Restoration of a stream channel to a naturalization process. In an technique, the outcome of stream “natural” state indicative of the pre‐ incised channel, that typically naturalization may be difficult to disturbed condition will be based on means excavation of the overbank predict. Whether a geomorphically anecdotal references, influenced by areas to an elevation consistent stable channel evolves and whether changes in the environment that are a with the bankfull depth of the that channel contains elements departure from the actual pre‐ disturbed condition of the channel. From that point, it is supporting a higher aquatic life use watercourse that is being restored. anticipated that the on‐going designation may only be • The watershed associated with the process of stream degradation and determined over the course of time. stream channel may contain opposing aggradation will That outcome is a common link conditions, such as land uses, that are eventually begin to influence the between all of the stream not conducive to sustaining a pattern and profile of the channel, restoration techniques described in “pristine” restored channel. Altered trending toward a point of this document. There can be no hydrology and or the influx of morphological stability. certainty on how each will perform sediments and other pollutants attributed to either agricultural or in the long run when it comes to urbanized land uses are examples of The benefits and drawbacks listed biological integrity; however, in these conditions. below assume that the stream this case, some of the known naturalization technique is applied elements to support that condition The premise of stream as a departure from the strict are left to evolve over time. naturalization is that a stream interpretation of natural channel system may “passively recover design; otherwise, the benefits and from past channelization activities, drawbacks of that technique can be eventually assuming a form and referenced from the earlier function generated by and discussion. The assumption is that compatible with the prevailing a more passive approach to stream environmental conditions”. This naturalization is being considered suggests that a watercourse, left that may include re‐establishment alone, can regain ecologically of the bankfull condition and a sound characteristics; however, it connected floodplain. also suggests that those characteristics will be influenced by the surrounding watershed. Given the substantial hydromodification

B I G D A R B Y A C C O R D C H A P T E R 3 . 0 ― L A N D U S E P L A N / 3-33 3.6.4 Funding for Another method of developing 3.6.5 Regional Planning for Stream Restoration Activities funding for stream restoration is Restoration Typically, funding for stream through the process of mitigation. Numerous variables may influence restoration must come from a For the purpose of this discussion, stream restoration within the combination of resources. mitigation is a process associated Accord planning area, including the Stream restoration can be identified with impacts to stream corridors chosen restoration technique and as a priority when determining that may occur in conjunction with where and when restoration how funding from the general site development or public opportunities may arise based on revenues generated by the Accord infrastructure improvements. The future development. To establish should be allocated. In doing so, draft NPDES permit for the Big more formal guidelines that the Accord could identify the Darby Creek watershed stipulates promote uniformity and a stream corridors along Clover Groff mitigation for impacts to stream coordinated approach to stream and Hamilton Runs as priority buffers, requiring restoration of restoration, it is recommended that areas for acquisition of open space. other stream buffers or actual there be an oversight group Where development is anticipated, channel restoration. Furthermore, responsible to the Accord Advisory the set‐aside of that stream corridor impacts that occur directly to Panel that is comprised of will ultimately occur. Alternatively, existing stream channels must meet individuals knowledgeable in the the Accord revenue could be used both state and federal permitting field of stream restoration and to provide supplemental funding guidelines that also require connected to the implementation of for the stream restoration activities mitigation. Typically, mitigation is the various components of the land in support of grant applications, in the form of an equal or greater use plan. The knowledge of these described below. amount of channel restoration and individuals should encompass the stream buffer preservation. various sciences that deal with There are grant funding programs stream restoration, including that may be available to the Accord To apply this concept to stream geomorphology and ecology. The or other entities that would assist in restoration opportunities within the group should also contain non‐ funding stream restoration Accord planning area may involve scientists who are representatives of activities. Examples of these a system that is based on an in‐lieu the watershed and can share the programs are the Clean Ohio Fund, fee payment whenever perspective of the individuals who administered locally through the development activities impact will “use” the restored stream Mid‐Ohio Regional Planning stream corridors within the channels. Commission, and the 319 Grant planning area. Fees collected for the program, administered through the purpose of mitigation would then Section 5.3.1 discusses the be pooled and applied to stream Ohio EPA. formation of an Environmental restoration. This process requires a Monitoring Group (EMG) to responsible entity to ‘manage’ the oversee the recommended water collection of mitigation funds and quality monitoring. This group apply them to stream restoration would likely have the technical opportunities that would meet he capabilities required for criteria of the NPDES permit and coordinated stream restoration other state / federal permitting oversight and should therefore guidelines. There is a defined assist with developing guidelines process for establishing this for stream restoration. A primary mechanism that would need to be goal of this group should be to followed by the Accord or some establish priority goals for stream other designated entity. restoration. Consideration should

include demonstration of ecological integrity and achieving the aquatic life use designations in accordance with the TMDL.

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3.7 Floodplain Management respect to floodplain management, they have adopted criteria Communities participating within requiring that structures be the National Flood Insurance elevated at least 1.5 feet above the Program (NFIP) have adopted 100‐year elevation and that there be regulations that determine the a minimum setback of 20 feet from extent to which encroachments can the revised limit of the floodplain. occur within the 100‐year Due to the restrictions related to floodplain and floodway. The encroachment within the regulations must meet a minimum designated floodway, standard established by FEMA. grading/filling within that area Within the ten participating related to development is generally jurisdictions of the Big Darby avoided. Encroachments within the Accord, there are some variations floodway related to roadway on what the standard is for crossings are common as a practical floodplain management, but they measure to avoid bridge or culvert are consistently applied in that all designs that are excessively grading/filling activities within the expensive to construct. 100‐year floodplain require a permit from the local jurisdiction. It should be noted that Brown Generally speaking, the NFIP‐ Township has adopted a derived regulations create the comprehensive plan recommending restrictions listed below. that no grading/filling occur within • Within the designated floodway, no the 100‐year floodplain. activity shall occur that would cause Furthermore, as one of Columbus’ an increase in the 100‐year flood higher standards, their revised elevation, unless there is prior review Stormwater Drainage Manual and approval of the project by FEMA. requires that any fill placed within The affirmative response from FEMA the 100‐year floodplain be in this situation is a Conditional mitigated with an equal volume of Letter of Map Revision (CLOMR) that excavation, performed in such a must be issued to the local manner that there is no loss of jurisdiction prior to the issuance of a floodplain storage. permit for that project. • Within the remaining portion of the Stream restoration is an anticipated 100‐year floodplain, outside of the activity within a designated 100‐ designated floodway, grading and year floodplain and floodway. filling activities may be permitted by Furthermore, referring to Section the local jurisdiction without the 4.2, there may be circumstances benefit of a technical analysis to where fill is placed within the 100‐ determine the impact to flood year floodplain in conjunction with elevations. In this case, fill may be stream restoration. Policy placed to remove areas from the 100‐ recommendations for floodplain year floodplain, with the likely intent management pertaining to these to change the land use in that area. circumstances are presented in Section 4.7.4. The regulations contain specific provisions that provide adequate protections for any development that would occur within the floodplain, requiring that any structures be properly elevated. Using the City of Columbus as an example of a higher standard with

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4.0 Land Use and Development Policies

With ten jurisdictions in the • Tier I – floodplain, riparian corridors, planning area, a number of land in‐stream habitat areas, wetlands, use policies are in place, including critical groundwater recharge areas, comprehensive plans and zoning pollution potential zones codes, to address planned and • Tier II – highly erodable soils, permitted development within the wooded areas greater than 3 acres watershed. In addition, several • Tier III – trails, habitat buffer areas, existing regulations, policies and connectivity corridors environmental initiatives have been Erosion and down-cutting along considered in the development of Green Building “Son of a Ditch” Tributary this plan as described in Chapter 2. Each jurisdiction should encourage Source: The Nature Conservancy/ A key factor in implementing the development that meets the Anthony Sasson Big Darby Accord Plan will be prerequisites identified within the finding an approach to Leadership in Energy and coordinating and enforcing current Environmental Design (LEED™). policies and new policies in a LEED™ encourages and accelerates consistent manner to ensure the global adoption of sustainable watershed is protected. This green building and development chapter describes the supporting practices through the creation and policies that each jurisdiction will implementation of universally need to consider as they implement understood and accepted Improved stream corridor zone and pursue adoption of the Big standards, tools and performance Source: EDAW Darby Accord Plan. criteria (USGBC, 2006). Guidelines for LEED™ for Neighborhood would apply to all changes in land 4.1 General Development Design (LEED ND) are in draft use within the planning area. It Practices form and should be encouraged for may also apply as a retrofit to residential developments. If a existing agricultural land uses Protection of Environmentally development meets or exceeds under a prescribed incentive Sensitive Areas identified LEED™ targets the program. This plan assumes that The main goals of the Big Darby jurisdiction should consider the policy for riparian corridor Accord planning effort are to providing some type of financial protection applies to future preserve and protect areas that incentive to the developer. development activities where the contribute the most to water quality, to protect them from 4.2 Environmental degradation from development Components Section Outline PG land uses and to improve the 4.1 General Development overall aquatic habitat within the Recommended polices related to Practices 4-1 Franklin County portion of the Big the protection of the riparian 4.2 Environmental Darby watershed. To establish corridor, floodplain and wetlands Components 4-1 some priority to the protection of are described in the following 4.3 Open Space 4-6 different environmentally sensitive sections. 4.4 Conservation areas, conservation tiers have been Development 4-8 established based on best available 4.2.1 Riparian Corridor Protection 4.5 Rural Development 4-9 data (see Section 3.1). These areas Riparian corridor protection is 4.6 Town Center 4-10 can be protected through policies essentially the establishment of a 4.7 Stormwater and programs established by each stream setback that, once Management 4-12 jurisdiction and through land implemented, precludes certain 4.8. Stormwater Best conservation efforts between the activities from occurring within a Management Practices 4-15 Accord and its partners. specified certain distance of all 4.9 Utilities 4-26 stream channels. The setback 4.10 Transportation 4-28 4.11 Trails and Greenways 4-29

B I G D A R B Y A C C O R D C H A P T E R 4 . 0 ― P O L I C I E S / 4-1 Key Recommendations • Adopt permitted, conditional and prohibited uses for open space areas based on Plan recommendations.

• Perpetual easements should be required for open space areas in conservation developments along stream corridor protection zones.

• All easements should be held jointly and in perpetuity by home owners association or local conservation group and either local jurisdiction or Franklin Soil and Water Conservation District.

• Jurisdictions should develop consistent guidelines for easement maintenance.

• Easement should have a 5 year staggered performance bond to ensure successful planting and design.

• Land areas associated with Tier 1, 2 and 3 resources may be counted toward the calculation of gross density of a development site.

• Development in proximity of regional trail system should be required to provide connections.

• Develop a regional trail along Big Darby and Hellbranch.

• Require 50% open space in all conservation developments and offer incentives for increases in open space.

• The location of open space in conservation developments should be dictated by environmentally sensitive resources in Tiers 1, 2 and 3.

• Open space in conservation developments should link to adjacent open space.

• At least 75% of the open space area in the conservation development should be contiguous.

• Development in conservation development should not front external roadways.

• Large lot development applicants should collaborate in lot layout and design.

• Large lot development should encourage that at least 50% of the site be place in conservation easement.

• The County should adopt proper legislation to review all development proposals that are greater than 5 acres in size.

• Establish an Open Space Advisory Council.

• The proposed mixed use Town Center should set a new standard for sustainable urban development.

• Brown and Prairie Townships should coordinate the development of new zoning for the Town Center area.

• The proposed Town Center should include a mix of housing types as well as commercial, retail, office, institutional and park uses.

• The stream corridor protection zone (SCPZ) shall be the greater of either the 100 year floodplain boundary, the calculated streamway (beltwidth) or a minimum of 100’ setback from centerline of intermittent, perennial and ephemeral streams.

• The SCPZ should include designated wetlands and slopes exceeding 15%.

• Adopt permitted, conditional and prohibited uses for SCPZ based on Plan recommendations.

• Allow stream restoration as a permitted or conditional use within the SCPZ.

• Protect the integrity of wetlands and diminish their loss within the planning area.

• Mitigation of any filled wetland should occur in the Darby Accord Planning Area.

• The SCPZ used to compute gross density must be delineated on plan and on site and must be placed in a joint easement.

• Pursue acquisition along Clover Groff and Hamilton Run streams for stream restoration. stream setback can be incorporated conducted cooperatively by The determined an equation for into the development process. The Ohio State University and the Ohio calculating a ‘streamway’, also commonly applied terminology for Department of Natural Resources referred to as a ‘beltwidth’. The the stream setback is Stream (ODNR) determined the stream original streamway/beltwidth Corridor Protection Zone (SCPZ). corridor necessary to accommodate equation was used to determine the stable stream channel Tier 1 stream setback (riparian Determination of the Stream geomorphology. The research buffer) areas in the environmental Corridor Protection Zone examined the meander pattern of sensitivity analysis, is referenced by There is consistency among the streams within Ohio and compared the Hellbranch Overlay and the referenced policies and it to information for streams Ohio EPA’s draft stormwater environmental initiatives with outside of the state, and related that general permit, and is a consensus regard to establishing the width of physical condition to the watershed recommendation of the EAG. stream setbacks. Research area of the stream. The research

4-2 / C H A P T E R 4 . 0 ― P O L I C I E S B I G D A R B Y A C C O R D Key Recommendations (continued) • Stream setbacks should provide adequate area for restoration activities.

• Incentives should be considered to encourage regional stream restoration efforts.

• Explore wetland mitigation banking.

• Work with the farming community to implement BMPs.

• Post construction groundwater recharge rate must equal or exceed pre-development recharge rates (NPDES/OEPA permit).

• Groundwater recharge areas should be protected through binding conservation easements.

• All site development plans must include a Stormwater Pollution Prevention Plan (construction phase).

• A sediment settling facility must be provided with a goal of releasing a max of 45 mg/l of TSS for up to a .75” rainfall in 24 hours (construction).

• Water quality volume control is defined by OEPA draft permit & siting requirements should be developed as part of the site design.

• Stormwater treatment and BMP design criteria must meet water quality targets set by the OEPA TMDL for TSS, TN and TP.

• Non-structural BMPs should be evaluated as part of the conceptual site design process.

• Minimize directly connected impervious areas.

• Follow the 8 step BMP planning process to determine required level of BMPs for site development.

• Utilize BMPs as identified in the BMP toolkit or other appropriate practices to meet water quality targets and plan goals.

• All post construction BMPs require submission of a maintenance plan.

• Easements are required for all BMPs to provide access.

• Regional stormwater facilities in Town Center should be maintained by a public entity, and site level BMPs should be maintained by the homeowner or homeowner association with proper operation and maintenance plan.

• Available sewer capacity for Town Center is 5,000 equivalent dwelling units; additional capacity may be available in the future.

• Provisions for extension of sewer service have been developed by City of Columbus.

• Town Center will receive central sewer through extension of the Big Run Trunk sewer.

• The Hilliard growth area and LEED area will receive central sewer through extension of the Roberts-Millikin sub trunk sewer.

• Franklin County Sanitary Engineer is identified as candidate for owning and operating the central sewer lines in Town Center.

• Areas not receiving central sewer would receive sewer service through alternative community-based sewage treatment systems.

• New standards and regulations related to methods, application and regulation of both community based systems & on-lot systems that meet OEPA and Board of Health requirements must be developed & applied

• Franklin County Sanitary Engineer has been identified as candidate for owning and operating community based sewage treatment systems

• Limit the proliferation of single-lot sewage treatment systems and encourage alternative community based systems.

W ‐ width of streamway/beltwidth recommendation from the Accord Note: Research related to the development of DA – drainage area in square miles is to apply the updated equation for the streamway/beltwidth equation is on‐ determining the SCPZ, which is going and is anticipated to result in changes Original equation: consistent with HWF to the equation. Further coordination with 0.43 W = 117 x DA recommendations. ODNR would be required to determine the (for DA less than or equal to suitability of a revised equation to 16 square miles) Updated and recommended equation: conditions within the Accord planning area. W= 87 x DA 0.43 W = 129 x D.A. 0.43 (for DA more than 16 square miles) (for DA less than or equal to 16 square miles) A more recent version of the equation is presented in the City of Columbus’ revised Stormwater Drainage Manual. The final policy

B I G D A R B Y A C C O R D C H A P T E R 4 . 0 ― P O L I C I E S / 4-3 For watercourses meeting the Although there is an incentive for • Permitted Uses: passive recreation, definition of a stream channel, the stream restoration, consideration vegetative enhancement, and arterial SCPZ shall be the greater of the should be given to the larger goals street crossings. boundaries described below. for restoration that are discussed in • Conditional Uses: stream bank • The FEMA designated 100‐year Section 3.6. Stream restoration stabilization, public utilities and non‐ floodplain (see floodplain discussion activities within the planning area arterial streets (Notes: the City of below and in Section 4.7). should be guided by a committee Columbus’ Stormwater Drainage • The calculated streamway/beltwidth that understands the restoration Manual allows for wetland mitigation using the updated equation. needs in a regional context. and enhancement of existing • A minimum of 100 feet extending Restoration activities that are not wetlands to occur within the SCPZ. from the centerline of the stream consistent with the larger goals While there is no precedent for this in channel on both sides of the throughout the planning area the reference materials described watercourse. should not be encouraged. above, it is suggested that the SCPZ policy account for certain stormwater Presently the Ohio EPA is Permitted, Conditional and BMPs to occur within this area as a considering a change to the draft Prohibited Uses conditional use. These BMP’s, such as NPDES permit for the Big Darby Permitted uses are allowed within grassed or enhanced swales, should Creek Watershed that would allow the SCPZ without restrictions. only be allowed where they are the SCPZ to be less than the width Conditional uses may occur only necessary to facilitate an outlet to the of a designated 100‐year floodplain. after further consideration by the receiving stream channel.) This allowance applies only when overseeing authority and may • Prohibited Uses: grading activities stream restoration is to be require the application of and land uses commonly associated performed along the specified reach conditions to be met as a with a development process and land of the watercourse. In this case, the component of that activity. An application of waste water effluent. physical modifications to the example of such a condition would watercourse may redefine the be mitigating activities to restore It is recommended that activities SCPZ. Furthermore, it may provide disturbed areas. Prohibited uses related to stream restoration be opportunities for different land may not occur except if granted a considered either a permitted or uses within the residual portions of variance or exception by the conditional use within the SCPZ. the 100‐year floodplain. This overseeing authority. The variance Designation as a conditional use approach is a strong incentive for or exception process has not been would give the overseeing stream restoration and is developed; however, it is authority the ability to review recommended for use within the foreseeable that the process would stream restoration proposals and Accord planning area. include a multi‐step evaluation establish and apply conditions for intended to demonstrate that the consistency related to restoration use, if approved, would have no activities within the larger planning degrading impact to water quality area. and/or habitat within the stream channel and would require Other Considerations mitigation as in the case of a Other recommended policies conditional use. related to SCPZ are described below. A detailed discussion of permitted, • Area set aside within the SCPZ may conditional and prohibited uses be used in computing gross site within the SCPZ is provided within density associated with a the EAG final report, Appendix 9‐3 development. of the draft revised 208 Plan and in • The extent of the SCPZ must be the policy recommendations clearly delineated and labeled on all provided by the HWF. Given that zoning, platting and engineering extensive documentation, a detailed documents associated with a discussion of those uses is not development. The location of the presented here; however, general SCPZ must be delineated in the field descriptions are provided below. during construction and permanently Ashy Sunflower designated in an aesthetically Source: Metro Parks/John Watts

4-4 / C H A P T E R 4 . 0 ― P O L I C I E S B I G D A R B Y A C C O R D harmonious fashion (often reflect the current meander pattern of should be followed with the intent interpreted as intermittent split rail the stream channel and may not be of contributing to stream fencing with appropriate signage). uniformly distributed on both sides. restoration opportunities within the • The SCPZ must be platted as a • The SCPZ should be extended to Accord planning area. ‘reserve’ area, not included within include designated wetlands and any individual platted lots and slopes that exceed 15‐percent where 4.2.2 Wetland Preservation placed in a permanent easement held those features begin within the and Mitigation jointly by an established homeowners established SCPZ. One objective of the Darby Accord association (residential) , land Plan is to preserve existing conservation group (501c3), or other Exceptions Within the SCPZ wetlands to the extent possible. property ownership (commercial) The draft NPDES permit for the Big Identification of existing wetlands and either the local jurisdiction or Darby Creek watershed contains within the planning area was FSWCD. A planting plan and provisions related to mitigation for limited by existing information management plan should be any impacts that may occur within available through the National developed for the easement that the specified stream setback area. Wetland Inventory. The actual outlines a program for planting the Furthermore, state and federal determination of jurisdictional easement and the regular inspection permitting guidelines related to wetlands within the planning area and maintenance of the dedicated impacts to perennial, intermittent must occur as part of any SCPZ easement. and ephemeral streams require a development process, wherein a • Enhancement of a degraded riparian suitable mitigation. In both verified delineation should be area in the form of planting of instances, the provisions would required. As stated within the appropriate vegetation may be result in restoration to riparian SCPZ policy recommendations, any required or could be implemented buffer areas and/or stream channel wetlands at least partially within under an incentive program. restoration that vary depending on the SCPZ is included within and the extent of the proposed impact. wholly protected under the Application of the Stream Setback Section 3.6 provides information provisions of the SCPZ. Requirement regarding the mitigation process The stream setback requirement and how it can be used to generate For wetland areas not protected by applies to all perennial, intermittent beneficial restoration within the the SCPZ, the U.S. Army Corps of and ephemeral streams, as defined Accord planning area. Engineers and the Ohio EPA have by the US Army Corps of anti‐degradation requirements Engineers. When determining the Areas within the Town Center are related to jurisdictional wetlands. setback boundaries, the following likely to be a higher density of Under Section 404 of the Clean considerations must be accounted: development and may encounter Water Act, the Corps of Engineers • The boundaries of the 100‐year difficulties when applying the can require a permit for fill of a floodplain should be interpreted SCPZ to all stream channels, jurisdictional wetland. Depending using the published 100‐year flood particularly ephemeral streams. In on the size of the wetland fill, the profile and the best available recognition of the importance of the requirement may be for a topography along the watercourse. Town Center to the economic Nationwide Permit (NWP) or for an The use of published flood hazard viability of the General Land Use individual permit, including a information, including 100‐year flood Plan and the need to generate Section 401 permit from the Ohio elevations or flood boundaries, beneficial opportunities for stream should include any Letters of Map restoration within the planning Correction (LOMC) issued by FEMA area, it is proposed, as an exception that include revisions to that to the stated criteria that the Accord information. LOMCs include Letters permit impacts to those channels of Map Revision (LOMR) and Letters within the Town Center area where of Map Amendment (LOMA). avoidance is not practical. When

• The width calculated from the impacts to stream channels streamway/beltwidth equation is a corridors occur, both the NPDES total width including both sides of permit for the Big Darby Creek Wetland the stream. The mapping of this watershed and state and federal width along the watercourse should Source: EDAW permitting guidelines for mitigation

B I G D A R B Y A C C O R D C H A P T E R 4 . 0 ― P O L I C I E S / 4-5 EPA, which requires mitigation for the loss of wetland area. Mitigation is typically in the form of replacement wetland acreage within a larger watershed area. Whether a delineated wetland is preserved or impacted by development activity on a site, policies should protect the integrity of wetlands and diminish their loss within the planning area. At Serenbe, a conservation development in the hill country of Georgia, 70% of • All delineated wetlands should be the land is protected in open space. properly documented and shown on Source: EDAW zoning, platting and engineering 4.3 Open Space documents associated with the

development process. The Accord jurisdictions should Permitted uses within open space • Site development design should work cooperatively to permanently areas should first consider ensure that adequate hydrology is protect Tiers 1, 2 and 3 areas. The environmental regulations maintained to any preserved wetland protection of these areas will be described in earlier sections that under the post‐construction made possible through adopted may prohibit certain uses in stream condition; however, the wetland policies as well as programs and corridor protection zones or cannot be used as part of the new funding sources that will be wetlands. stormwater management scheme for created by the Accord. Efforts to • Permitted Uses: passive recreation a development. Preserved wetlands protect land must be coordinated including trails, vegetative should be adequately delineated in across jurisdictions and among enhancement, reforestation, removal the field and protected from agencies that are already working of damaged or diseased trees, stream stormwater runoff during in the planning area such as ODNR, bank stabilization/restoration, public construction. Metro Parks and FSWCD. utilities, non‐structural best

management practices, minor Verification of any required The identification of disturbances related to the permitting for wetland fills must be environmentally sensitive resources construction of the permitted use, provided as a condition of final should be a requirement for all land application of waste water approval of the site development development proposals as part of a effluent (outside SCPZ or wetlands) plan. Due to the length of time development review checklist that • Conditional Uses: active recreational commonly associated with an is further described in Section 5.0. uses limited to multi‐purpose fields, individual permitting process, Development plans and proposals playgrounds some consideration may be given to should demonstrate the protection • Prohibited Uses: grading activities allowing a demonstration that the of resources to the maximum extent and land uses commonly associated permitting process is substantially possible. The location of open space with a development process, complete. on any development site, such as a development

conservation development that sets Mitigation of any filled wetland aside 50% of the site, should be Land Acquisition areas should occur within the dictated by the location of The Accord should support Metro planning area and incentives can be environmentally sensitive features Parks, FSWCD, The Nature provided. Allowing wetland within the tiers and the topography Conservancy, NRCS, ODNR and mitigation to occur within the and features of the land. others in their efforts to acquire and SCPZ or within converted (from Development should be permitted protect land. The Accord General agriculture) or preserved within the Tier areas, subject to all Land Use Plan and conservation conservation open space that is part zoning, subdivision regulations, tiers should in no way limit or of the Accord planning area should permitting and environmental hinder conservation efforts of other be considered. standards set forth in this Plan and organizations for lands that may be

other regulatory requirements such outside the tiers. To implement the

as those issued by the Ohio EPA. plan and help protect water quality

4-6 / C H A P T E R 4 . 0 ― P O L I C I E S B I G D A R B Y A C C O R D goals, Accord jurisdictions should that are part of any conservation‐ Maintenance of Open Space Areas target acquisition efforts to Tiers 1 style development and along All jurisdictions should adopt and 2. Elements within these areas SCPZs. Easements can provide consistent guidelines for the that include: economic benefits to property maintenance and care for privately Tier 1 owners. For larger lot held open space lands or land held • Floodplain developments that occur outside of within easements. These guidelines • Riparian Zones conservation developments, local should be developed in • Wetlands jurisdictions should encourage at coordination with Open Space • Critical groundwater recharge areas least 50% of the site be placed in a Advisory Council. Overall, it is the • Pollution potential zones conservation easement to ensure desire that open space in Tier 2 proper care and natural vegetative conservation subdivisions is • Highly erodable soils features. managed such that the recharge • Wooded acres greater than 3 acres rate is maintained or improved. If All easements should be held onsite infiltration is infeasible, or if Open Space Advisory Council jointly and in perpetuity to allow open space is inadequate to The Accord should establish an for perpetual inspection and maintain this infiltration rate, Open Space Advisory Council to enforcement. Appropriate parties mitigation with off site infiltration provide guidance for land for the joint easements include may be allowed. acquisition, funding and other Home Owners Associations, conservation efforts. The Advisory qualified conservation groups To encourage the proper and most Council should include (501c3), local governmental entities, ecologically beneficial conversion of representatives from Metro Parks, or the Franklin Soil and Water denuded areas to areas with native Franklin Soil and Water Conservation District. vegetation and plantings, Conservation District, The Nature developers should be required to Conservancy, ODNR, OEPA, Appropriate uses for the open work with Franklin Soil and Water NRCS, OSU Extension and the local space, maintenance requirements, Conservation District and the local affected jurisdictions. and overall treatment of the jurisdiction to develop a planting Consideration can also be given to easement should be stipulated in plan for any open space easement. including interested land owners the easement agreement. A ‘double’ The planting plan should be and local conservation easement will allow access to the submitted at the time of application organizations. Members on the site for inspection, enforcement, and should identify appropriate Advisory Council should have a and monitoring of the open space native plants, soil requirements and role in land ownership and/or and enforcement of easement water requirements for the open oversight in the Accord planning requirements. In the event the party space area. area. The Accord and Open Space responsible for maintenance of the Advisory Council should organize open space easement fails to Developers should be required to a series of roundtable discussions to maintain all or any portion in plant the initial cover and should be encourage dialogue among reasonable order and condition, the subject to a 3 year performance residents about the benefits of land appropriate governing body should bond too ensure a successful conservation and to encourage assume responsibility for its outcome followed by a 2 year bond participation in programs. This maintenance and should enter the at a reduced rate to ensure effort should emphasize the value premises to take corrective action, maintenance procedures are of open space and can be including the provision of extended followed. The performance bond coordinated to educate property maintenance. The costs of such will be released upon inspection by owners about best management maintenance should be charged to the local jurisdiction. The use of practices. the homeowners association, or to stewardship fees should also be the individual property owners that considered as a way to cover Easements make up the homeowners administrative, inspection and legal To ensure that open space areas are association and may include costs associated with perpetual properly maintained and managed administrative costs and penalties. enforcement of easements. FSWCD over the long‐term and to ensure Such costs should become a lien on has developed a stewardship fee continuity of care between property all subdivision properties. model that should be consulted for owners, easements should be applicability. created for the open space areas

B I G D A R B Y A C C O R D C H A P T E R 4 . 0 ― P O L I C I E S / 4-7 Furthermore, as part of the planting 4.4 Conservation • Purpose and Authority plan, the applicant should submit a Development • Definitions long‐term management plan that • Requirements for clustering provides for the following: Conservation development is the • Designation and treatment of 1. Allocates responsibility (easement) recommended land use approach open space and guidelines for the maintenance for new development in areas • Regulations for open space and operation of the open space and outside the Town Center, in the • Permitted land uses and any facilities including ongoing Hilliard growth area, and in select residential densities maintenance and long‐term capital locations along the eastern border • Minimum acreage requirements improvements; of the City of Columbus. • Bonuses/Incentives 2. Cost estimates and staff requirements Conservation development will • Requirements for easements, for maintenance, operation and provide increased opportunities to maintenance and oversight insurance for the easement and protect important natural resource of open space identification of funding sources; features and water quality, provide • Provision of underground utilities 3. Provides for any changes to the plan opportunities to reduce costs • Other development standards to be approved by the local governing related to best management (setbacks, signage, trees) body; and practices through natural 4. Provides for future enhancement of applications and provide It is strongly recommended that the the plan and allows for stream opportunities for the application of Accord jurisdictions discourage restoration activities. approved community wastewater conventional subdivisions, which treatment technologies. A are inconsistent with the goals of minimum parent tract size of 20 this plan, by building in flexibility acres of contiguous land is and incentive opportunities with suggested for conservation conservation development. In developments in the rural and addition, conservation Hilliard growth areas. developments should strive to provide a mix of residential options Local ordinances must facilitate and housing types. conservation‐style development. Accord jurisdictions should work Character together to develop an (overlay) Conservation developments should zoning classification for celebrate the rural character of the conservation development areas watershed. Housing types should consistent with the General Land be varied within developments and Use Plan map. It is recommended encourage creativity to meet the that Brown, Prairie and Pleasant needs of mixed incomes. Dwelling Townships work together with the units should not be permitted to County to develop an overlay front along any existing external ordinance that could be applied to roadway. all three jurisdictions to address the rural conservation development Design and Open Space land use category. The City of Requirements Hilliard should create a Development potential of any conservation development zoning conservation development will district that parallels the rural need to take into consideration conservation overlay but is oriented environmental site conditions, to 1 unit per acre. Collaboration required best management among the jurisdictions will ensure practices, environmental policies continuity and consistency in and the availability of on‐site sewer application and provide property and water. Development should owners and developers with more minimize site disturbance and clarity. At a minimum, the promote the efficient use of land. conservation development zoning should address:

4-8 / C H A P T E R 4 . 0 ― P O L I C I E S B I G D A R B Y A C C O R D Land Land # of to 20 feet to reduce impervious Open Space Conserved Developed Bonus Lots or surfaces and encourage the slowing Preserved Acres Acres Density Units of traffic. If homes are provided Rural 50% 50 50 Zero 20 with garages and driveways Area roadways should not be required to 100 40 provide for on‐street parking. acres 60% 60 15% 23 Common driveways should also be encouraged. Other reductions in Figure 4.1 Example Rural Conservation Development Area Incentives impervious surfaces may be Source: EDAW achieved through the elimination of curbing or application of pervious Development in these areas must reduced. Appropriate density surfaces for sidewalks, driveways be designed using a cluster increases must consider impact on and pathways and flexibility in approach with a minimum of 50% local utilities and should be turning radii. General street design of the gross area of a development evaluated on a case by case basis. guidelines should allow flexibility. site set aside as natural open space.

This concept is commonly When considering density The design of conservation associated with and promoted by incentives, it is recommended that developments should be flexible to Randall Arendt in a book entitled the maximum increase of units be reserve the best available soils on “Rural by Design.” At least 75% limited to a 10‐15% increase over the site for sewage treatment of the open space within a the gross permitted density. purposes (Arendt, 1994). In conservation development (based Additional density bonuses may be addition to meeting proper on gross area of the site) should be appropriate in the rural areas if the regulations and standards, a contiguous tract. (OEPA 208 development proposal can community based sewage systems Plan). The open space should adjoin demonstrate it meets requirements will require dedicated land area to any neighboring areas of open for community‐based sewage function, and will have other space, other protected areas and treatment. Figure 4.1 shows how a design impact considerations that non‐protected natural areas that density bonus can be applied. will need to be factored into would be future candidates for development processes. protected open space. The Accord jurisdictions should contiguity requirement may be consider offering incentives for 4.5 Rural Development waived if the use of the open space applicants that agree to complete in another fashion is necessary to stream restoration. The method for Large lot development is defined achieve important ecological stream restoration should be for the purpose of this Plan as protection or to maximize consistent with Accord Plan exceeding 20 acres per unit. This ecological benefit. recommendations and should be style of development is currently encouraged on a regional scale permitted throughout the planning Any area of natural open space that where maximum benefit can be area and will continue to be is proposed to be disturbed during achieved. permitted, subject to applicable construction or otherwise not regulations and standards. Current preserved in its natural state Impervious Surfaces regulations also allow for lot splits should be shown on development Overall, impervious surfaces within of less than 20 acres. It is plans and should be restored conservation developments should recommended the County adopt with vegetation that is compatible be minimized through design and proper legislation to review all with the natural characteristics application of low impact development proposals that are of the site. development techniques. Accord greater than 5 acres in size. This jurisdictions should review measure would create an Density subdivision regulations to ensure opportunity for the County to Greater open space set asides are built in flexibility to allow for discuss potential incentives and encouraged in all conservation appropriate reductions in road alternatives to conventional development areas by a sliding width requirements, parking and development, including scale approach that allows the gross driveways. Roadways in conservation development. density to rise if the net area conservation developments should consumed by development is consider widths of no more than 18

B I G D A R B Y A C C O R D C H A P T E R 4 . 0 ― P O L I C I E S / 4-9 If there are multiple applications The portion of the Town Center extend to I‐70 where it would be for large lot developments or that falls within Prairie Township is appropriate to locate more smaller lot splits in a concentrated already zoned at densities that regionally oriented uses that have area, the local jurisdiction, or could support higher density access to I‐70 via a new county, should coordinate the residential development. However, interchange. developers and identify an the goal of the Town Center is to agreeable approach to achieving the promote a mix of uses including Character conservation areas in a contiguous parks and open spaces, a mix of The organization of the Town manner and providing shared residential housing types, Center should reflect traditional driveways and internal access commercial and office. To Town Center practices and roads to eliminate frontage lots on maximize the presence of adequate recommendations of the Big Darby external roadways. It is strongly infrastructure, the Town Center Accord Town Center general recommended that large lot owners should encourage development at design standards described below. maintain at least 50% of their home high densities. As part of the master Town Center development should site as a conservation easement planning process, Prairie and have the following characteristics: with natural, vegetated landscape Brown Townships should jointly • A mix of uses both horizontally and such as prairie grasses to minimize develop zoning regulations that vertically the application of fertilizers and allow for this mixed use Town • A mix of residential housing types improve infiltration capability. Center. Section 5.0 describes the including affordable housing recommended steps and • Pedestrian orientation/ADA Homes on large lots should considerations for completing a Accessible incorporate a range of best joint master planning process for • Quality streets management practices at the unit the Town Center. • Well organized public spaces, level including rain gardens, native including formal and informal parks plantings and pervious pavements Development Capacity of the • Architectural variety and interest as well as native landscaping. Town Center • Energy efficiency and The level of growth in the Town sustainable design Large lot developments will most Center will be dependent on both • Maximization of density likely require on‐site septic systems the ultimate sewer capacity as well and will be subject to regulations as the success of the Big Darby The Town Center should regarding the inspection and Accord in discouraging accommodate uses and densities monitoring of those systems. Lot development in conservation areas that allow for transitions from the design and layout will be impacted and focusing it in the Town Center. high density Town Center to the by the approach to on‐site For these reasons, the Town Center low density rural character treatment. should be developed in a series of surrounding the Town Center, as phases related to the extension and described in Section 3.0. 4.6 Town Center capacity of centralized sewer. Planning for sewer capacity should Town Center Land Use Policies related to the development consider the long‐term needs of the Policies related to defined land use of the Town Center are intended to Town Center and should be types in the Town Center should be provide basic guidelines. As a designed to allow the Town Center further developed in the Master priority, development of the Town to grow over time as improvements Plan process. The overall goal for Center should minimize impacts to to the sewer system are funded and the Town Center is to create a any existing environmental features completed and the ability to meet dynamic community with a high that currently exist in the area and water quality standards is quality of life for residents and strive to set a new standard for demonstrated. visitors. sustainable urban development. Detailed phasing of the Town Mixed‐Use Development Master Plan Center should be addressed as part Mixed use development should be The Accord jurisdictions should of the master planning effort. encouraged particularly along the immediately and jointly pursue the However, based on the proximity major pedestrian oriented streets. completion of a Town Center to existing sewer lines, Phase 1 Mixed‐use includes retail on the 1st Master Plan. should include areas along West floor with either office or Broad Street. Later phases should residential uses above. Mixed‐use

4-10 / C H A P T E R 4 . 0 ― P O L I C I E S B I G D A R B Y A C C O R D development should include windows, pitched roofs, step backs, count toward parking requirements continuous retail uses along key etc., can be utilized. and shared parking should be streets with generous pedestrian strongly encouraged. areas to encourage walking. Residential Subdivisions A variety of residential units should The building presence on a primary Individual Lot Commercial be available throughout the Town roadway should not be dominated Development Center, including multi‐family and by pavement. Parking should be Individual lots should adhere to an single family. It is recommended a placed behind buildings or in established streetscape plan. Town portion of the housing units in the parking structures where feasible. Center jurisdictions should Town Center be affordable units. Curb cuts should be limited on establish a street hierarchy and Multifamily units should be primary roadways for vehicular accompanying street typology to arranged in a traditional fashion and pedestrian safety. dictate the form of individual sites. with traditional building types, This will result in a street of either in townhomes or apartment Any parking associated with a large consistent and strong character. All buildings in the H, U or I form or a footprint building should be buildings located along the public donut form where residential units minimized by reducing the paved roadway in the Town Center surround a parking structure. areas, incorporating low impact should meet all standards Single family homes should also be development options (such as established for the street including traditional in architecture, scale and pervious pavement, swales, etc.) build‐to lines, pedestrian access, siting but allow for creativity and and integrating landscape islands, architecture and use. uniqueness. Garages should not or other means. Parking ratios dominate the façade; alleys should should be established as part of the Large Scale Commercial Development be provided at the rear to allow master plan process. Large scale developments that may garages to locate behind a house. include a ‘big box’ anchor store and Street Design outparcels should not be isolated Design Standards All roads within the Town Center developments. They should relate The following are recommended should adhere to an established to and connect to all other design standards for the Town hierarchy based on the type, development in the Town Center Center. amount of traffic and proximate and adhere to the established street uses. A streetscape plan should be hierarchy and typology. Vehicular Site Design created as part of the master plan to and pedestrian connections should Site design will be the greatest establish the typology for all roads be made on all sides of the contributing factor to the eventual and address sidewalk width, lawns, development to reduce traffic quality of life in the Town Center. street trees, distance from building pressure. The building arrangement to curb, relationship of the building should be well organized and any Build‐to lines should be established to the street, etc. Alleys should be internal circulation efficient and to create a built edge along any located behind all developable effective. Pedestrian amenities public roadway. This will parcels to provide rear access should be provided throughout contribute to the street character locations. Pervious materials the site. and organize the development. All should be considered for alleys. buildings should address all public Streetscape improvements should Large Footprint Buildings roadway and have strong be enumerated and required as part To achieve good design for a large relationship with the primary of each development. footprint building, careful attention roadway. The front door of a to siting and architecture is critical. building should be accessible by Connections Efforts should be made to minimize pedestrian walkways. Strong, safe and attractive the mass of the building by pedestrian and bicycle connections breaking up any building façades. Parking, Circulation and Access should be created throughout the Vertical elements should be Parking should not be a dominating Town Center. Pedestrian and car incorporated to break up the length land use in the Town Center and conflict points should be avoided of each face and horizontal internal circulation should be well and pedestrians should be able to elements should be used to reduce organized. Parking requirements safely maneuver from the street to the building massing. Fenestration should be flexible; on street parking any building door. Direct detail, recesses, extrusions, spaces on public roadways should connections from sidewalks to

B I G D A R B Y A C C O R D C H A P T E R 4 . 0 ― P O L I C I E S / 4-11 buildings should eliminate the need evoke architectural interest and regulations and policies used by the to navigate through a parking lot to variety to achieve design goals – various jurisdictions to oversee the access a building. faux storefronts and thin facades development process. To simplify above rooflines should not be this process, a single set of policies, Five foot sidewalks should be the permitted. Multi‐story buildings rules and regulations should be minimum width for any sidewalks and pitched roofs should be developed that is unique to the within the Town Center. Increased encouraged. Green roofs and other Accord planning area and can be sidewalk and street widths may be sustainable design elements (LEED) administered throughout the entire required to accommodate bicycle should be encouraged. area. facilities. Design and construction of sidewalks should consider a Public Spaces 4.7.1 Stormwater Quantity Control variety of options including Well organized and well designed The recommended detention impervious materials. A public spaces will be essential for (quantity) controls are adapted multiplicity of vehicular the success of the Town Center. Not from the City of Columbus’ connections should be made only should the preferred location recently revised Stormwater throughout the Town Center of public spaces be designated, a Drainage Manual. The criteria whenever possible to help relieve hierarchy should be established so represent an approach to traffic congestion and connect that all public space needs are met, stormwater detention referred to as neighborhoods. There should be no passive and active, formal and the critical storm method. isolated developments. informal. Leisure trails should • The runoff volume from a site during provide connections within and out a 1‐year, 24‐hour storm event is Landscaping of the Town Center. calculated for pre‐ and post‐ Landscaping and vegetation will be development conditions. The critical a necessary element for achieving 4.7 Stormwater Management storm for sizing the stormwater the overall goals of the Accord plan detention facilities is then determined related water quality. Vegetated Development in Accord planning based upon the percent increase in and natural areas reduce area will need to meet a new runoff volume due to the proposed impervious surfaces and can standard of quality in order to meet development (pg. 3‐3 of City of provide benefits for stormwater the water quality goals of the Ohio Columbus Stormwater Drainage management. Landscaping should EPA and of this Plan. Stormwater Manual). be required within all setback areas management policies for the Big • Runoff from storm events less than or abutting an existing or planned Darby Accord Plan are tied to equal to the critical storm calculated public right‐of‐way and be required maintaining and improving water event is to be released from the in all off‐street parking areas in quality and the aquatic life use development site at a rate no greater order to visually break up large attainment within planning area than the peak runoff during the 1‐ areas. Landscaped areas may serve watercourses. Stormwater year event under pre‐developed many functions and should be management requirements will conditions. integrated into the overall become applicable as development • Stormwater detention facilities are to stormwater management plan applications are submitted and be sized so that the peak runoff where applicable. reviewed. during the 100‐year storm event with the post‐developed condition is Screening Better Site (Low‐Impact) released at a rate less than or equal to Screening should be required for Design Principles for the peak runoff from a 10‐year storm parking, all utilities, dumpsters, Stormwater Management under pre‐developed conditions. mechanicals and other building It is recommended that better site necessities from all sides. design practices, as defined in 4.7.2 Groundwater Section 3.0, be incorporated into Recharge Criteria Buildings local zoning ordinances, planning Evaluation of the post‐construction Building types within the Town policies and/or subdivision groundwater recharge rate from the Center should vary. All buildings regulations within the Accord structural and non‐structural best should have a strong presence on a planning area. Further investigation management practices (BMPs) primary street. Building details is required to determine the nature within the developed area is should be traditional in nature and of the changes that will need to be required as part of the Ohio EPA’s incorporate natural materials that made to the current ordinances, draft NPDES permit.

4-12 / C H A P T E R 4 . 0 ― P O L I C I E S B I G D A R B Y A C C O R D stormwater BMP that promotes control measures that will meet the The draft permit requires that the infiltration. Implementation of requirement of the permit. For post‐construction groundwater infiltration‐based BMPs must take sediment control, specifically, a recharge rate must equal or exceed into account soil suitability and the sediment settling facility must be the pre‐developed recharge rates, potential for groundwater pollution. provided that has a measurable as defined within the permit. It is In this scenario, the groundwater goal of releasing no more than 45 recommended that recharge areas recharge facility would most likely be mg/l TSS for up to a 0.75 inch include areas such as low elevation owned by and the responsibility of rainfall in 24 hours. The size of the undisturbed hydric soils, the property owner or homeowners disturbed project area (greater than floodplains and riparian corridor association. A majority of the soils or less than 5 acres) may determine areas. An equation and table to be within the Accord planning area have the type and size of sediment used for calculation of the annual characteristics not suitable for settling facility required. For sites average groundwater recharge implementation of infiltration smaller than 5 acres, other rates from various land uses and practices. For most of the “filtering” measures of sediment control than soil groups is included in the draft BMPs discussed in Section 4.8, it is a settling facility are permitted; version of the NPDES permit. assumed that an underdrain system however, the likelihood of Furthermore, the draft permit will be necessary; however, even obtaining the target rate of TSS recommends that the groundwater those systems provide an advantage becomes reduced. recharge (infiltration) areas be toward promoting the interaction of protected through binding surface flows and the shallow aquifer Post‐Construction conservation easements that that is a contributor to a sustained Performance Goals identify a third party management stream base flow condition. The TMDL report for the Big Darby agency, such as a Creek defines allowable release homeowners/condominium 4.7.3 Stormwater Quality Control rates in kilograms per year for the association, political jurisdiction or Recommended policies related to pollutants of concern within the third party land trust. The addressing water quality are Accord planning area in addition to implementation of ownership of associated with stormwater runoff defining a percent removal for each groundwater recharge areas may criteria stipulated by the Ohio of those pollutants from the vary depending on the chosen EPA’s draft NPDES permit for the existing conditions within the practice for meeting the Big Darby Creek watershed, watershed. For example, within the requirements. including the specific criteria for Hellbranch Run watershed, the the portion of the watershed required percent reduction in the If the determined post‐ contained to Franklin County. The existing TSS and TP load within the development recharge rate is less Ohio EPA is currently in the watershed is 95% and 81%, than the pre‐development rate, two process of re‐visiting some of those respectively. There are separate options are available: criteria, and some of the specifics of values for percent pollution 1. Additional land within the planned those policies may be changed in reduction presented in the TMDL development can be converted to a the final version of the permit; for other areas within the Accord land use with higher recharge however, when final, the permit planning area; however, it is potential. This area should be part of will be a mandate for all anticipated that a performance goal the conservation open space that is development within the watershed. related to post‐construction water part of the development site or The various components of the quality will be adopted that is allocated off‐site open space areas NPDES permit as they pertain to uniform throughout the planning that are required to achieve the water quality are listed below. Each area. Presently, the Ohio EPA is proposed development density in of these was discussed in detail in contemplating a numerical non‐conservation development areas. Section 3. pollutant load requirement that In this scenario, the groundwater would apply to stormwater runoff recharge areas would be allocated Construction Phase released from a development site within land that is likely to be held in Stormwater Control rather than percent removal public trust as part of the open space All development site plans must efficiency as defined in the TMDL. component of the Accord planning include a Stormwater Pollution The pollutant load number, likely area. Prevention Plan (SWPPP) that in milligrams per liter, would allow 2. A portion of the runoff from a contains details and specifications for a quantifiable measure of development can be directed to a for runoff, erosion and sediment success simplifying the design and

B I G D A R B Y A C C O R D C H A P T E R 4 . 0 ― P O L I C I E S / 4-13 monitoring process related to As mentioned in Section 4.2, the storage. The documentation should implementing BMPs. Ohio EPA is considering a consist of volume (of fill and provision within their changes to excavation) calculations and a Furthermore, this plan includes the draft NPDES permit for the Big certification from a registered requirements for monitoring of Darby Creek watershed that would professional engineer that the individual site developments to allow the SCPZ to be less than the calculations accurately reflect the determine compliance within an extent of the 100‐year floodplain if proposed activity. established performance goal. stream restoration occurs along that Chapter 5 discusses the reach of the channel. Given this implementation of the monitoring consideration and the discussion of program and its associated existing floodplain regulations performance bond. under Sec. 3.7, the criteria listed below are recommended. Water Quality Volume The water volume criteria Floodway Encroachment contained within the Ohio EPA’s Stream restoration activities along draft permit will be the degraded stream channels that are determining requirement for the FEMA‐studied will certainly design of stormwater BMPs involve grading/filling within the sufficient to meet the drawdown designated floodway. In order to times also stipulated in the permit. permit this activity, it is Calculations prepared as part of a recommended that the established development site design would minimum standards of the NFIP be need to be prepared demonstrating followed, requiring a determination that the BMP feature is capable of through a technical analysis of the providing the storage volume and impact of the activity on 100‐year has an outlet structure adequately flood elevations. The same criteria sized to meet the drawdown time apply to any proposed bridges or criteria. culverts involving components within the floodway. It is possible 4.7.4 Floodplain Management that a CLOMR will be required The determination of the extent of from FEMA before the local the 100‐year floodplain boundary is jurisdiction can issue a permit for described in conjunction with these activities. Given the establishing the SCPZ (Section 4.2). recommended SCPZ criteria, no Within that section, it is generally other activities are anticipated that established that a FEMA‐ would require floodway designated 100‐year floodplain can encroachment and the application serve as the limits of the SCPZ. The of these criteria. protection of the 100‐year floodplain from encroachment due Floodplain Filling to fill placement is regarded as a The contemplated changes to the measure to both provide an NPDES permit for the Big Darby adequate riparian buffer along Creek will leave residual floodplain significant watercourses within the areas outside of the SCPZ that planning area and to also address could be filled for development flooding concerns along those purposes. Should fill be allowed watercourses. within the 100‐year floodplain under this condition, it is recommended that documentation be provided with the permit application demonstrating there will be no loss of floodplain

4-14 / C H A P T E R 4 . 0 ― P O L I C I E S B I G D A R B Y A C C O R D 4.8 Stormwater Best application of BMPs as a way to more suited for removal of fine Management Practices protect stream and water quality in sediments and dissolved addition to stormwater flow control constituents. Dissolved As recognized in the Columbus provides an added benefit to the contaminants require long Stormwater Drainage Manual, watershed. residence times, high soil‐water stormwater management, contact, and the opportunity for particularly in the area of BMPs have been categorized to vegetative uptake (Hellbranch stormwater quality management, is focus on those techniques most Watershed Pollutant Modeling an evolving science. Therefore, it commonly used for residential report, March 2005). Combining will be important to review development. The application of BMPs can often result in a more stormwater policies when BMPs is typically associated with efficient and effective treatment updating this plan as science, an entire residential development system. For example, a BMP system technologies, industry and design or subdivision. The BMPs discussed may incorporate a structural facility will likely evolve. Information herein span watershed level in combination with grassed within this section has been applications and individual swales, vegetative buffer areas, compiled from a number of property applications. The actual marsh vegetation or other resources including the Ohio design of a BMP typically falls into nonstructural BMPs in order to Department of Natural Resources one of three categories: structural, achieve the desired storage volume (ODNR), the Hellbranch Watershed non‐structural or management/ and site coverage requirements. At Forum (HWF), the Darby Creek policy related. times, non‐structural BMPs may be Watershed Task Force, the City of required or desirable in order for Columbus Stormwater Drainage The Hellbranch Watershed study the structural BMP to operate at Manual, the United States EPA, the reviewed BMPs and similarly maximum efficiency. Because BMPs Northern Virginia BMP Handbook, categorized them based on type: must slow down or temporarily the City of Olympia, Washington The most common examples of structural detain the stormwater runoff in Stormwater Manual and the BMPs include extended detention dry order to achieve the desired Chesapeake Bay. ponds, wet pond, and infiltration pollutant removal efficiencies, trenches. Some non‐structural BMPs, BMPs also provide a measure of Best Management Practices (BMPs) which may be used in conjunction with water quantity control as well. The are structural or non‐structural structural controls, include street extent to which peak runoff rates practices, management practices, or cleaning, vegetative buffer areas, grassed are reduced varies depending on a combination of these techniques, swales and fertilizer application control. the type of BMP applied. that when used in solitude or in Some BMPs such as ponds and swales, combination, minimize the impacts are generic features often provided in 4.8.1 BMP Planning Process of agricultural or urbanized land contemporary developments; however, As part of the preliminary planning uses on water quality by removing unless they were designed as BMPs, they process for development within the or reducing pollutants. may be ineffective at removing pollutants planning area, decisions will need from the stormwater runoff. BMPs have to be made regarding the types of BMPs are most commonly specific design and construction criteria BMPs that will be utilized on each associated with post‐construction and maintenance requirements that must site. Information was compiled to storm water management be adhered to in order to achieve the help both developers and plan techniques that treat runoff from a reported pollutant removal efficiencies reviewers in determining the development site after construction (Hellbranch Watershed Pollutant appropriate BMPs for a site. The is completed. BMPs capture and Modeling report, March 2005). information presented here is not treat pollutants found in runoff and meant to be exhaustive or exclusive; manage the frequency, volume and Pollutant removal processes vary other BMPs not listed here may be energy of the runoff so that water considerably among BMPs. Due to acceptable, but they will require resources are not degraded differences in these removal additional review and (ODNR). Historically, storm water processes, identifying target documentation to ensure that the ponds were used to reduce constituents is crucial for optimum goals of the Big Darby Accord are downstream flooding because they BMP selection. Most BMPs are being met. detain water and release it at a effective at removing large slower rate while also allowing particles, while well‐vegetated Limited performance and design settling of sediments (ODNR). The basins and infiltration methods are information is presented here; this

B I G D A R B Y A C C O R D C H A P T E R 4 . 0 ― P O L I C I E S / 4-15 information should only be used should be required prior to planning area in the Big Darby for determining which BMPs development plan approval. Creek TMDL report, however, it is should be selected for a site to meet possible that information exists for the appropriate design criteria. It is BMP Selection Considerations individual development sites and it the responsibility of the site Selection considerations presented is suggested that the developer designer to identify the specific here are aimed largely at water review all available resources to design criteria necessary to quality control but do not remove determine if additional data exists complete the design of the BMP the requirement for a development for their site. and present it to the reviewer. site to control the quantity of Much of the information presented stormwater runoff from their site. The following BMP planning here is adapted from the State of process can then be used by both Minnesota’s Stormwater Design Non‐structural BMPs, which reduce developers and by reviewers to Manual, November 2005. the volume and peak flow of select appropriate BMPs that stormwater runoff from a address both the proposed Green roofs, pervious pavement development site, should be development and the pollutants of and rain water harvesting (e.g. rain evaluated as part of the conceptual concern listed in the TMDL or any barrels, lot level rain gardens, dry site design process. The benefits to other documentation that may wells) are not primary BMPs, and both the developer and the become available in the future. should not be considered part of community from incorporating the required treatment train for a non‐structural BMPs is reduced Step 1. Determination of development. The implementation runoff, reduced pollutant load for whether development is large or of these particular BMPs will allow BMP treatment, reduced cost for small development the designer to decrease the amount drainage infrastructure, and If a development disturbs five or of impervious cover on a site, reduced long‐term site more acres of land or is part of a which can have an impact on the maintenance. Several approaches, larger common plan of design of the other BMPs specified. discussed in detail as part of “Better development or sale that will Site Design” principles (Section 4.7) disturb five acres of land, the BMPs The summary information include methods to reduce chosen for the site must either be presented in Figure 4.2 and Section impervious areas and to increase capable of treating the larger 4.8.3 includes an overview of infiltration through placement of drainage area, or the site must be information on design criteria, grass buffers and swales. split up into smaller, distinct sub‐ benefits and limitations as well as watersheds such that the BMP the mechanism by which the BMP Minimizing the directly connected limitations noted in the summary functions, the pollution removal impervious area requires a change table are not exceeded. efficiency (in percent removal), site in land development design design factors such as maximum philosophy. Traditional land Step 2. Determine whether or drainage areas tributary to the development practices do not focus not development site is BMP, depth to the water table, and on water quality concerns but tributary to a regional stormwater the scale at which each BMP is most rather promote runoff from the site management facility. effective (development level versus to a curb and gutter stormwater It is anticipated that parts of the lot level). Filtration practices, as conveyance system. This practice planning area, particularly the described below, include grass concentrates runoff quickly, town center area, will develop in channels, dry swales, wet swales resulting in large peak runoff rates such a manner that regional and filter strips. Infiltration during small storms. stormwater management facilities practices, as described below, will serve as part of the BMP include infiltration basins, The first step of planning for treatment train for multiple infiltration trenches, dry wells, and stormwater management BMPs developments. If a development underground detention. Filtration within a development begins with site is located within an area that is devices and hydrodynamic devices the collection of data on the local tributary to one of these regional are proprietary systems that are receiving waters and information facilities, it is likely that the on‐site available from multiple regarding pollutants of concern BMPs for the development will manufacturers, and evidence of within the downstream watershed have to meet a different pollutant independent testing of the area. The OEPA has already removal efficiency that has been performance of these devices compiled this information for the previously specified, as the regional

4-16 / C H A P T E R 4 . 0 ― P O L I C I E S B I G D A R B Y A C C O R D facility will meet a portion of the basin inserts, and manufactured include large wet ponds, wetland required control for the area. The systems. systems, media filtration and removal efficiency required at the manufactured systems. The site site level would then be determined Step 5. Determine if infiltration is suitability and design criteria for on a case by case basis. practical for pollutant removal. each BMP should be reviewed to Infiltration BMPs are effective determine compatibility of the BMP If a development site is not alternatives for both treating with the specific development site. tributary to a regional management stormwater runoff and for facility, the responsibility of addressing groundwater recharge. Step 7. Select BMP application meeting the target pollutant The effectiveness and applicability based on suitability to site removal efficiencies must be of infiltration BMPs is dependant The factors a designer should accomplished within the site. upon local soil properties. Factors consider as part of this step include which determine if infiltration is the items discussed previously, and Step 3. Determine site conditions practicable include soil type, also include the size of the runoff related to stormwater runoff location and depth to bedrock, the area, the final appearance of the The site conditions that a developer water table, presence of BMP and the functionality of the must determine include runoff impermeable layers, and proximity BMP. Information presented in volume, peak flow rates and water to wells, foundations, septic tank Figure 4.2 details both the runoff quality considerations. The drainfields, and unstable slopes. area that each BMP is best suited to stormwater runoff conditions Soil types which are appropriate for treat as well as the functionality of should be calculated for both the infiltration BMPs include coarse the BMP. The attached BMP pre‐ and post‐development sand to loamy sandy deposits. summary information also has condition such that the controls Infiltration practices can also be photographs of fully developed necessary for the post‐development used in clayey soils with the use of BMPs, so that developers can condition may be tailored to meet an underdrain system, connected to determine whether or not a specific the requirements outlined in other the stormwater conveyance system BMP will visually fit within the sections of this document. It is for the site. It is recommended that overall site plan. during this step that the developer infiltration BMPs be preceded by a should determine the post‐ pretreatment facility such as a pre‐ Step 8. Final Site Design development pollutants that are settling basin to reduce the and Layout likely to be present to assist in BMP sediment load entering the Following the selection and location selection. infiltration BMP. Infiltration BMPs of stormwater BMPs on the site, the include infiltration basins, developer should proceed to the Step 4. Determine the need infiltration trenches, and bio‐ final layout and design of the for oil control BMPs. infiltration swales. If infiltration is development. The development Oil control BMPs should be applied considered a practicable BMP for design must comply with all local to sites likely to generate high the site, a pre‐treatment BMP and zoning ordinances as well as with concentrations of oil due to high infiltration BMP should be selected all Accord development policies traffic turnover or the frequent and sited within the proposed and the Draft NPDES Permit for transfer of oil and gas. The development. Construction Activities. following urban area land uses should be considered as high use Step 6. Determine level of Final Review and Approval. sites requiring oil control BMPs: phosphorous control required. The developer must then submit railroad yards; fueling stations; The need for phosphorous control the finalized stormwater vehicle maintenance and repair is outlined in the TMDL for the Big management plan and report and sites; construction businesses; Darby Creek watershed. The level development plan to the reviewing industrial machinery and railroad at which phosphorous control is authority. equipment maintenance areas. If needed will be dependent on the the proposed development is likely type of development proposed and 4.8.2 System Ownership to generate excessive whether or not the site is tributary and Maintenance concentrations, an oil control BMP to a regional facility that may The long‐term inspection and should be selected. BMPs which provide some phosphorous maintenance of the stormwater control the oil content in runoff removal. BMPs that reduce the control facilities is critical to include oil/water separators, catch phosphorous content in runoff continued performance.

B I G D A R B Y A C C O R D C H A P T E R 4 . 0 ― P O L I C I E S / 4-17 The NPDES permit for the Accord Accord representatives have If it is determined that a BMP is not planning area requires submission suggested that all on‐site systems to be publicly owned and of a maintenance plan for all post‐ will be maintained through the maintained, the developer of a site construction BMPs. These plans are owner or homeowners associations should be required to submit an to be provided to the owner/ and all detention basins and operation and maintenance report operator of the site (including constructed wetlands will be that details, at a minimum, who is homeowners associations) prior to maintained by a public entity responsible for maintenance of the the completion of construction (county, community authority, facility, the frequency and type of activities. A description of the municipality, township, etc.). maintenance that will be required funding mechanism must be Regardless of the ownership for the facility and the method of included in the maintenance plan to specified during the planning reporting this information. Other ensure all BMPs are maintained in process, an easement will be details of the operation and perpetuity. required for all BMPs such that the maintenance of the facility may be public entity may gain access to required at the discretion of the For the planning area, maintenance ensure and facilitate maintenance reviewing authority. If it is of the stormwater facilities will be as necessary. determined that the responsible divided into these two basic party is not meeting the goals of the categories: The Town Center concept promotes operation and maintenance report, 1. On‐site systems (bioretention cells, regionalization for stormwater the public entity will have the swales, filter strips etc.) management facilities. These ability to access the BMP through 2. Detention systems regional facilities would be the required easement and perform (detention/retention basins or maintained by a public entity. Any maintenance required. There are constructed wetlands). site level BMPs required in this area several mechanisms for recouping will be maintained by the the cost of this activity from the site development site owner or owner/operator. Use of the homeowners association. performance bond (included in the discussion of monitoring) or assessments should be considered.

4-18 / C H A P T E R 4 . 0 ― P O L I C I E S B I G D A R B Y A C C O R D 4.8.3 BMP Toolkit Green Roofs Pervious Pavement

Design Criteria Design Criteria • Structural load capacity is a • Pervious pavement is typically used major factor in determining in low traffic areas including whether the green roof is overflow parking areas, emergency “extensive” or “intensive” vehicle lanes, and pedestrian areas • Vegetation selection is based • In‐situ soils should have field‐verified on numerous factors including, minimum permeability rates greater growth depth, microclimate, than 0.3 in/hr. Contributing runoff irrigation and maintenance from offsite should be limited to a 3:1 • A leak detection system is ratio of impervious area to pervious recommended to quickly detect pavement area Example of Green Roof and locate leaks • The selected systems load bearing Source: Low Impact • Modular products can increase surface should be suited to maximum Development Center installation and repair efficiency intended loads • Design storms should be infiltrated Benefits within 48 hours • Reduce, delay and cool stormwater runoff Benefits • Insulate buildings and lower energy • Good for highly impervious areas – consumption and costs particularly parking lots • Provide habitat for birds and insects • Reduces need for other storm water • Increase longevity of traditional BMPs by reducing runoff roofing systems by protecting from • Construction costs of some systems ultraviolet rays are less than traditional paving Example of Pervious Pavement • Reduce carbon dioxide levels and • Soil‐enhanced turf systems resist Blocks, Washington, DC heat island effect compaction, increase infiltration, and Source: Low Impact provide soils for healthier vegetation Development Center Limitations • Cost is higher than traditional Limitations roofing systems – can be • Construction costs of some significant for retrofits systems are more expensive than • Leaks can cause significant damage traditional paving and can be hard to locate and repair • Use depends on infiltration without detection system rates of underlying soils • Conditions can be harsh for • Maintenance costs are higher than vegetation establishment conventional paving • Maintenance needs can be higher • Not recommended for high traffic than traditional roofing systems areas because of durability concerns Example of Pervious Pavement Application in Residential Area Source: Low Impact Development Center

B I G D A R B Y A C C O R D C H A P T E R 4 . 0 ― P O L I C I E S / 4-19 Rain Water Harvesting Chemical and Biological Treatment Design Criteria • The system should be watertight, Design Criteria have a smooth interior surface, be • Properties of water to be treated located on level and stable ground, (pH, sediment concentration, etc.) have a tight‐fitting lid, good screens • Level of treatment desired on the inlet and outlet and have an • Requirements for discharge of treated emergency overflow device water to receiving water bodies • To prevent the breeding of • Type of facility required or present mosquitoes, empty the water in less • Pre‐treatment or secondary treatment than 5 days or place a fine screen over requirements all openings • Maintenance and monitoring • Material can withstand the pressure requirements of the system Example of Rain Water Harvesting of water over long periods of time Residential rain barrel ― Stillwater, MN • Disconnect and drain rain barrels and Benefits cisterns in the winter to prevent • Quickly removes suspended freezing and deformation of the rain clays and silts water harvesting system • Can be used as pre‐treatment to remove suspended sediments prior Benefits to infiltration • Protects water supplies by reducing • Can help project meet stringent water use during peak summer months clarity and sediment bound pollutant • Mimics the natural hydrology of the removal standards area by infiltrating a portion of the • Suitable for cold climates rain water falling on the site Example of Chemical and • Reduces volume of storm being Limitations Biological Treatment delivered to downstream waterbodies • Ongoing operation and maintenance Tanners Lake alum injection facility ― • Results in cost savings by reducing of the chemical addition system may Oakdale, MN municipal water bill be required • Monitoring may be required to Limitations determine the impact on • Not suitable for the following roof downstream resources types: tar and gravel, asbestos shingle • A pond or sediment collection area is and treated cedar shakes necessary downstream of the • Depending on the design, requires a treatment site for settling out the certain amount of operation and flocculants maintenance • May require permitting from • Proprietary systems can be expensive OEPA for discharge • Expensive to build and operate Example of Rain garden Source: EDAW

4-20 / C H A P T E R 4 . 0 ― P O L I C I E S B I G D A R B Y A C C O R D Filtration Devices Hydrodynamic Devices

Design Criteria Design Criteria • Pollutants of interest for reduction • Expected flow rates • Desired removal efficiency • Pollutants of concern • Design flow for volume, site • Desired removal efficiencies constraints on size, desired location • Site constraints for size of treatment unit • Installation and maintenance costs, • Pre‐treatment requirements life of unit • Installation and maintenance costs, • Need for accessory structures life of unit Benefits Benefits • Units are typically underground and • Units are typically underground or do not consume much site space within existing structures and do not • Can often be easily incorporated into consume much site space fully developed sites • Filtration devices can be customized • Can be used for pre‐treatment prior to reduce a specific pollutant of to other practices concern • Suitable for cold climates if installed • Can often be easily incorporated into below frost line fully developed sites • Can be used for pre‐treatment prior Limitations to infiltration practices • Each type of unit has specific design Examples of Filtration Devices • Relevant for use on industrial sites constraints and limitations for use Proprietary systems used as examples because filters can remove pollutants • Treatment may be reduced if frequent only, NOT an endorsement such as metals and oils maintenance is not conducted • May not meet local standards when Limitations used alone • Efficiency has not been widely tested • Generally good for solids and litter, • Each type of unit has specific design but much less effective for other constraints and limitations for use common pollutants • Can be more costly than other treatment methods • Treatment may be greatly reduced if frequent maintenance is not Example of Hydrodynamic Device conducted Courtesy of Minneapolis Public Works • Subject to freezing in cold climates Department

B I G D A R B Y A C C O R D C H A P T E R 4 . 0 ― P O L I C I E S / 4-21 Bioretention Filtration Practices

Design Criteria Design Criteria • Infiltration requires suitable soils • Ensure adequate space for • Minimum 10‐foot setback and located filtration system down grade from home foundations • Some installations require • Best applied to drainage areas with 2‐6 feet of head relatively flat slopes (5%) • Removal potential of the key pollutant Example of Bioswale Planting Benefits • Parent material and potential for Source: EMH&T • Can be very effective for removing ground water contamination fine sediment, trace metals, nutrients, bacteria and organics Benefits (Davis et al. 1998) • Good for highly impervious • Provides many additional areas with low sediment/high environmental (habitat, improves pollutant load (e.g. urban land use air quality, urban micro‐climates), and retrofit scenarios) social (creates a unique sense of • High pollutant removal rates place), and economic benefits • May be used in a variety of soil types (reduces development and • Good for treatment of hotspots maintenance cost, greater lot yield, because it can be isolated from increases property values) ground water if contamination • Well suited for high impervious areas concerns exist Example of Filtration Practices • Reduces runoff volume Public Library, Alexandria, VA • Flexible design, affording many Limitations Source: EDAW opportunities for creativity • Higher maintenance requirements • Some installations (media filters) Limitations have higher construction costs • Susceptible to clogging by • Potential to cause odor problems sediment; therefore maintenance • Minimal treatment of soluble and pretreatment is necessary to nutrients maintain effectiveness • Potential for nitrification in • Not effective for large drainage areas media filters where anaerobic (use multiple structures, closer to conditions exist source of runoff) • Space consumption (5%‐10% of drainage area)

4-22 / C H A P T E R 4 . 0 ― P O L I C I E S B I G D A R B Y A C C O R D Infiltration Practices Stormwater Ponds

Design Criteria Design Criteria • Contributing drainage area • Irregularly shaped with a minimum • Underlying soil types length to width ratio of 1.5:1 • Depth to the water table, bedrock or • Permanent pool volume to 1800 cubic other impeding layer feet per acre draining to pond • Proximity to buildings, drinking • Permanent pool depth 3‐foot water supplies, karst features, etc. minimum, 10‐foot maximum at • Source of stormwater runoff deepest points Example of Infiltration Practices • Extended detention (ED) Infiltration trench, Benefits storage sufficient to treat water Lino Lakes City Hall ― Link Lakes, MN • Reduces volume of quality volume stormwater runoff • Pre‐treatment required • Increases groundwater recharge (sediment forebay sized at 10% of • Improves surface water quality pond area recommended) • Provides thermal benefits • Stabilized emergency overflow and (e.g. to cold water fisheries) energy dissipation at all outlets • Mimics pre‐development hydrology Benefits Limitations • Able to effectively reduce many • Unusual construction considerations pollutant loads and control runoff • Potential for groundwater flow rates contamination • Relatively straightforward design Example of Infiltration Practices • Tendency to lose effectiveness over procedure Underground storage and infiltration, time due to clogging – if not properly • Potential wildlife habitat and Bradshaw Celebration of Life Center ― constructed and maintained aesthetic or recreational enhancement Stillwater, MN • Not recommended for areas with • May be used as temporary steep slopes sedimentation basin during • May require landscaping: construction consideration should be given to periods on inundation and drought Limitations • Relatively large space requirement • Tends to increase water temperature and may cause downstream thermal impact • Potential for nuisance insects or odor • Problematic for areas of Example of Stormwater Pond low relief, high water table, Source: EDAW or near surface bedrock • Possible safety concerns

Example of Stormwater Pond Source: EDAW

B I G D A R B Y A C C O R D C H A P T E R 4 . 0 ― P O L I C I E S / 4-23 Stormwater Wetlands

Design Criteria • Water budget should be calculated to ensure proper drainage area and to ensure that wetland conditions can be maintained. • Minimum length to width ratio of 2:1 should be maintained during low Example of Stormwater Wetland flow or baseflow conditions. Stillwater, MN • Minimum of 35% of the total wetland surface area should have a Minnesota BMP images were taken depth of 6 inches or less; 10% to 20% from the State of Minnesota Stormwater Design Manual, November 2005 of surface area should be deep pool (1.5 to 6 feet deep) • Constructed wetlands require about 2% to 4% of the area that drains to them. • Thermal effects of discharged waters from stormwater wetlands on receiving bodies of water should be considered.

Benefits • Good suspended solid and annual nutrient removal • Provides good wildlife habitat and aesthetic value • Low maintenance costs • Provides ground water‐surface water interface

Limitations • Requires more land than other practices • Requires careful design and planning to ensure wetland hydrology is maintained • Water quality behavior can change seasonally

4-24 / C H A P T E R 4 . 0 ― P O L I C I E S B I G D A R B Y A C C O R D

Figure 4.2 Structural BMP Summary

B I G D A R B Y A C C O R D C H A P T E R 4 . 0 ― P O L I C I E S / 4-25 4.9 Utilities would own and maintain the sewer certain provisions, some of which lines that extend or connect to the are listed below. These provisions 4.9.1 Centralized Sewer Big Run Trunk Sewer and then would become policy associated Centralized sewer service will be contract to the City of Columbus for with the Accord planning process. provided to both the designated treatment. The detail of these provisions and Town Center and the proposed the possibility of other provisions Hilliard growth area that resides The Franklin County Sanitary are still being developed. within the City of Hilliard’s Engineer, recognized as a • The local authority must adopt contract service area. Hilliard’s Designated Management Agency the Big Darby Accord Plan current contract service area is (DMA) within the Regional Facility • The local authority must north of Roberts Road and extends Planning Area (RFPA) that includes show evidence of adequate west of Alton and Darby Creek the Accord planning area, has been public service related to fire Road. These central sewer systems identified as a candidate to act as and safety to serve the would eventually discharge to a the local authority responsible for development areas. larger sewer system that is owned owning and operating the sewer • The planning process must and operated by the City of lines in this area. As noted incorporate a provision for a Columbus. Current capacity previously, there is a recognized component of affordable housing limitations exist within the central sub‐Regional Facility Planning Area stock within the Town Center. sewer system. Additional central that overlaps with the Town Center • The planning process considers sewer capacity may be made (Lake Darby Estates). If they are environmentally sound mechanisms available over time as not, themselves, responsible for for providing wastewater treatment improvements to the overall system providing the sewer service within applications in areas of their RFPA are completed. Decisions regarding that area, then a formal agreement that are not going to be served by the allocation of any future capacity with Ohio American Water would central sewer systems. would need to be determined. be required under the 208 plan to allow the local authority to have The phasing of development within Centralized sewer service will also that responsibility. A review of the the Town Center will facilitate the be provided to the LEED area east provisions of the draft revised 208 initial extension of the trunk sewer of Alton and Darby Creek Road. plan and coordination with the to within proximity of the Town Capacity exists for approximately Ohio EPA is necessary to determine Center development area. It is 1,400 equivalent dwelling units in the requirements related to possible that the local authority will this area. Central sewer service may establishing the Franklin County have to develop a funding also be provided in a manner Sanitary Engineer as the recognized mechanism that would assist with consistent with the Accord general DMA for this area and address any the initial cost of extending the land use plan to some sites closer to issues related to the establishment trunk sewer line, which would then the existing system that were of a sub‐Regional Facility Planning be reimbursed as additional previously annexed or are zoned Area or “satellite community” development occurs. for development. designation associated with the Town Center. Hilliard’s Growth Area Town Center The Hilliard growth area will The Town Center will receive sewer Based on an analysis of available receive sewer service through the service through the extension of capacity within the Big Run extension of and connection to the and connection to the Big Run Sanitary Trunk Sewer line, the City Roberts‐Millikin Sanitary sub‐ Trunk Sewer. Presently, the trunk of Columbus currently estimates Trunk Sewer. Presently, the sub‐ sewer terminates near Broad Street the sewer capacity available to the trunk sewer terminates east of at the eastern edge of the Accord Town Center area is 5,000 Alton‐Darby Creek Road and north planning area. The City of equivalent dwelling units. of Roberts Road. Several smaller Columbus has suggested that Additional capacity in the trunk sewer lines extend from the sub‐ service would occur in a manner sewer may be made available over trunk sewer to other areas within similar to other contracted satellite time as improvements to the overall Hilliard and within proximity to communities within the central system are completed. Because this the extended contract service area; Ohio area, such as Hilliard. area would remain unincorporated, however, these were designed for Without the area being annexed to the City has requested that the local local capacity only and some of Columbus, the local authority authority adopt and implement these extensions include pump

4-26 / C H A P T E R 4 . 0 ― P O L I C I E S B I G D A R B Y A C C O R D stations. An analysis of the systems (HSTS) (also referred to as being sought in terms of meeting a available capacity of this sewer line household sewage disposal high degree of certainty that the determined sufficient capacity systems). Presently, there is a systems will provide a long‐term and exists within the Accord planning proliferation of HSTS within the cost‐effective solution to sewage are for an additional 2,000 rural areas of the planning area and treatment. equivalent dwelling units. concerns have been raised • The management and operations are regarding the operation and effective, and regulatory oversight is Hilliard will likely annex this area performance of these systems, sufficient. The working group as development occurs and, particularly with regard to home recommends that the systems would therefore, the development and aeration systems. be acceptable if they are publicly associated sewer service will be owned and operated, they are subject to the provisions of Section 2.2 references committees installed in compliance with an Ohio Hilliard’s service contract with the working on technical and EPA Permit to Install, and they are City of Columbus. regulatory issues pertaining to operated in compliance with an sewage treatment in non‐central acceptable Ohio EPA Permit to LEED Area sewer areas (referred to as working Operate. The Ohio EPA does not The Accord general land use groups). The technical committee currently have a Permit to Operate plan designates an area east of has developed preliminary mechanism for these systems. The Alton and Darby Creek Road and recommendations for alternative Ohio EPA will be publishing south of Roberts Road, known as wastewater systems that are proposed rules to create this the LEED area, for development at included in Appendix F. mechanism in the near future. The approximately 3 dwelling units per working groups propose that these acre, in addition to an area of mixed Community‐based Alternative rules must adequately address the use. The LEED area may be Sewage Treatment Systems criteria listed below. annexed by Columbus and is The intent of these systems would 1. Effluent limitations designated to receive central sewer be to collect sewage from a 2. Monitoring requirements service via the Roberts Millikin combined area for treatment, 3. Operator qualifications sanitary subtrunk. The capacity for including land application of 4. Siting criteria, considering this area is approximately 1,400 effluent, avoiding a direct discharge field tiles, soil types and equivalent dwelling units, although to any watercourse. The working isolation distance the mixed use development will groups (referenced in Section 2.0) 5. Storage of effluent include non‐residential uses. discussing these systems have 6. Application rates/conditions for both identified the Franklin County spray and drip irrigation Additional Central Sewer Areas Sanitary Engineer as a candidate to Upon issuance of the proposed Ohio The Columbus central sewer be the local authority that would EPA rules, the working groups system may also have additional own and operate these systems. As propose to review and determine if capacity for some areas closer to with the issue of the central sewer all stipulated provisions have been the existing system, currently systems elsewhere in the Accord adequately provided. annexed or zoned for development planning area, the issues related to and able to be served, in a manner the provisions of the 208 Plan must On‐lot Systems consistent with the Accord general be investigated to establish which Although it is intent of the Accord land use plan. are applicable to this arrangement. Plan to limit the circumstances The working groups have under which a single‐lot sewage 4.9.2 Non‐centralized Sewer identified the described approach treatment system would be A substantial part of the planning to be the preferred method of required, it is anticipated that some area is identified for rural wastewater treatment service for low‐density development will conservation development. These those areas that are not intended to continue to occur that is not part of areas are removed from where be served by centralized community‐based systems. As such central sewer service is planned; wastewater treatment systems it is anticipated that future home therefore, these development areas under the following conditions: sewage treatment systems (HSTS) would need to be served by an • The technology applied is applications are likely. Current alternative community‐based appropriate. Land application, or rules and regulations pertaining to treatment system or would have drip irrigation, systems have various permitting and oversight of these household sewage treatment applications and the state‐of‐the‐art is systems are inadequate.

B I G D A R B Y A C C O R D C H A P T E R 4 . 0 ― P O L I C I E S / 4-27 Maintenance and care of these causing organisms in groundwater The technical committee addressing systems by individual homeowners and surface water the issue of HSTS is determining is a concern and has likely resulted 10. Standards for bacteria, BOD5, and recommendations on HSTS design in malfunctioning systems that, TSS, and enabling local government standards. These recommendations collectively, are a contributor to to establish nutrient reduction will consider issues related to water quality degradation within standards (e.g., nitrate, designing for curtain drains, the the Accord planning area. phosphorous, etc.) acceptable minimum depth to 11. Criteria for the installation of seasonal high water table, pre‐ The working groups discussed in gradient drains (installed around the treatment applications and whether Section 2.2 are considering this entire HSTS) and interceptor drains to recommend household irrigation issue, standards and regulations (installed upslope of a ‘Wisconsin systems or lagoons. governing these systems. Currently, Mound’ system) these systems are under the 12. HSTS design standards to protect 4.10 Transportation authority of the Franklin County human health and surface flow and Board of Health and would remain groundwater With the Town Center being the under that authority. The Ohio 13. Installation inspection requirements heart of development within the Department of Health Ohio Sewage of new HSTS Big Darby Accord, it is imperative Treatment and Disposal Rules will 14. Education of the homeowner on the that a more detailed transportation become effective January 1, 2007. operation and maintenance of HSTS plan be defined for the immediate These rules contain most of the 15. Mandatory service contracts for drip area. Since the transportation plan elements necessary for regulation, distribution or any HSTS with a has a significant influence on the oversight and management of the ʺpre‐treatmentʺ component appearance, character and vitality alternative wastewater treatment approved by ODH of the area, it must provide for safe, and disposal systems proposed for 16. Mandatory one‐time 18 month convenient and efficient movement consideration by the Darby Accord. inspection of all new HSTS after of vehicular, pedestrian and bicycle These necessary elements are listed effective date of rule traffic within and adjacent to the below. Town Center. 1. Soil absorption criteria and site The Franklin County BOH intends evaluations to rescind their current rules and When an overall master plan is 2. Demonstration of competency in enforce the minimum State rules by developed for the Town Center, the performance of soil and site the effective date of those rules. The traffic engineering and evaluators, septage haulers, working groups recommend for transportation studies should be designers, and installers consideration by the Accord the undertaken as various land‐use and 3. Responsibility (homeowner) for adoption of the following local urban design plans are considered. proper siting, design, installation, BOH rules by the effective date of Through this process, traffic monitoring and operation/ the State Rules: volumes can be projected and maintenance • Require mandatory monitoring, assigned to the roadway systems. 4. Oversight of the county Board of operation and maintenance service Based on analyses of the projected Health (BOH) by the Ohio contracts in accordance with link and intersection volumes, Department of Health (ODH) on manufacturerʹs recommendations or roadway needs in terms of number compliance with the new rules BOH operational permit of lanes can be determined. The 5. Criteria related to subdivision requirements for all new HSTS. roadway cross‐section needs can development with HSTS • Consider the establishment of an then be married with the desired 6. Installation Permit requirements Operational Permit Program for all street character (such as open ditch 7. Operation Permit issued by BOH for existing HSTS not regulated by such or curb and gutter, median, tree all new HSTS permit (e.g., septic tank and leach lawn, sidewalk, bike path, etc.) to 8. Requirements for on‐going field type systems) and, further, for identify desired right‐of‐way monitoring, operation, maintenance the Operational Permit to include the widths. Guidelines should also be of HSTS by homeowners requirement for monitoring, established regarding access 9. Adequate separation from limiting operation and maintenance service management for streets and soil conditions (e.g., seasonal high contracts. roadways within the Town Center water table, etc.) to allow for to maintain the integrity and treatment in the soil profile to mobility function of the roadway protect human health from disease system – particularly along the

4-28 / C H A P T E R 4 . 0 ― P O L I C I E S B I G D A R B Y A C C O R D conceptual north‐south spine road any adopted parkland dedication connecting US 40 with I‐70. requirement. The network of greenways and trails throughout Over time it will be important for the planning area should link the Accord jurisdictions to further neighborhoods with one another, consider long‐term transportation with schools, parks and other implications of the plan for the natural areas. broader planning area. A regional traffic study would help direct Public and private trails should be infrastructure investments. It could developed for river access and the also provide guidance as local enjoyment of nature. Trail jurisdictions work with specifications include: development proposals to ensure that proper access is provided and Paved Trails necessary improvements are made • Trail surface: (hard) asphalt to the surrounding roadway system or concrete to ensure a minimum level of • Trail width: minimum 10’ ‐ service. Regional traffic studies maximum 12’ have been undertaken in Franklin • Clearing width: maximum 20’ County on several occasions with (clearing width not included as the multi‐jurisdictional Northwest part of setback) Traffic Study being a recent nearby • Distance from the edge of the example. stream: minimum 300’ • River access points may be 4.11 Trails and Greenways developed but must be unpaved • Private trails should not have The Accord should support efforts crossings and crossings on public to develop regional and local trail trails are a conditional use and systems that link parks and open should be permitted only if they are spaces. Development of a regional part of a comprehensive trail plan trail along both the Big Darby and Hellbranch Run within dedicated Unpaved Trails easements should be pursued in • Trail surface: coordination with developers, (soft) compacted gravel or land owners and Metro Parks. In approved natural surface addition, the Accord should • Trail width: minimum 5’ ‐ support the development of a maximum 12’ trail along the existing rail corridor • Clearing width: maximum 20’ that extends from Columbus to the (clearing width not included as Big Darby. part of setback) • Distance from the edge of the stream: The design and construction of minimum 200’ greenways and trails should be a • River access points may required improvement for all be developed development plans that are within proximity of a regional trail and considered for smaller site developments. Developers should be required to provide and construct these amenities during the site development. The local jurisdiction should provide flexibility to meet this requirement evaluating whether it could satisfy

B I G D A R B Y A C C O R D C H A P T E R 4 . 0 ― P O L I C I E S / 4-29

4-30 / C H A P T E R 4 . 0 ― P O L I C I E S B I G D A R B Y A C C O R D 5.0 Implementation

Implementation of the Big Darby 5.1 Big Darby Accord development of the site. Both steps Accord Plan will require Advisory Panel require review under existing coordinated effort among a jurisdiction processes; however, number of key stakeholders, A fundamental goal of the Big currently no mechanism ensures including property owners that Darby Accord is to ensure that the consistency among Accord will be multi‐jurisdictional, multi‐ zoning and site development jurisdictions when reviewing plans level, and multi‐faceted. Figure review processes are fair, consistent in accordance with this Plan. 5.1 has been developed to and apply evenly to all areas of the A Big Darby Accord Advisory illustrate the major levels of planning area so the plan Panel is recommended to fulfill an activities needed to implement implementation moves forward. oversight function to the review the Plan, including a new Big process and create a mechanism for Darby Accord Advisory Panel, The processes for zoning and site collaboration among the technical review activities among development are different. Zoning jurisdictions. The recommended the jurisdictions and other changes the use and development structure is similar to the Rocky regulatory agencies, a requirements for a site and is Fork‐Blacklick Accord Panel that Community Authority and other usually the first step in has successfully reviewed partnerships. These levels are development. Site development development plans in the Plain further defined in the following includes a building program, and Township area for Columbus and sections. site plans are created for New Albany since 1997. The Big Darby Accord Advisory Panel enhances the standard review Key Recommendations process that exists today, • Establish a Big Darby Accord Advisory Panel facilitating it for both the developer • Establish an Environmental Monitoring Group and Accord jurisdictions while • Establish an Open Space Fund ensuring the protection of the Big Darby Creek. • Establish a Land Stewardship Program

• Create a uniform parkland dedication ordnance The broad role of the Big Darby • Develop a Purchase of Development Rights Program Accord Advisory Panel would be to • Explore Density Transfer Charges and Transfer of work together to implement the Development Rights Programs Plan. Confirming that land use • Establish a backyard conservation program changes and zonings are consistent with the general land use plan and • Prepare a Town Center Master Plan plan policies, establishing open • Establish a New Community Authority space conservation areas, ensuring • Establish Tax Increment Financing (non-school) • Establish Developer Contributions with flexibility Section Outline PG • Establish level of service needs for community services 5.1 Big Darby Accord • Establish a Monitoring Program with watershed and site-level Advisory Panel 5-1 applications 5.2 Development • Appoint staff to carry out implementation Review Process 5-2 • Update the plan every 5 years 5.3 Other Coordinated Activities 5-8 • Develop centralized tracking system for development/conservation 5.4 Open Space and Land • Revise the development review process and incorporate a Protection Programs 5-18 development review checklist 5.5 Revenue 5-25 • Complete a Memorandum of Understanding among the 5.6 Early Actions 5-28 Accord jurisdictions

B I G D A R B Y A C C O R D C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N / 5-1 unincorporated areas of Franklin County should continue with the added responsibility of ensuring consistency with the Big Darby Accord Plan. Technical committee roles are described in Figure 5.2.

The Big Darby Accord Advisory Panel should be comprised of a combination of representatives from the Accord jurisdictions. The composition of the panel may be influenced by existing personnel resources and available expertise; however, it should represent the interests of all of the jurisdictions within the planning area. Figure 5.3 sets forth a recommended panel representation; the composition of the Panel will ultimately be determined by members of the Accord.

The Accord jurisdictions should consider the need for having dedicated staff to assist the Big Darby Accord Advisory Panel in its roles and duties. Dedicated staff could serve administrative duties and facilitate coordination among the jurisdictions and various Figure 5.1 Various Roles and Responsibilities for Plan Implementation technical agencies and partners.

5.2 Development adequate public facilities and recommendations would be Review Process overseeing adaptive management strongly considered in the formal principals are the focus areas for review process. Each jurisdiction Coordination related to the the Advisory Panel. will continue to be responsible for development review process and final plan approval or denial for the role of the Big Darby Accord The Big Darby Accord Advisory proposals in their area. Advisory Panel and supporting Panel would share responsibility technical review is described this with the local governing Specific details related to the site section. jurisdiction to review and render development process would remain advisory, non‐binding opinions on under the review of the The description of the zoning and zoning applications and site jurisdictional authority. Established site development review processes development plans in terms of processes for coordinated technical is intended as a general explanation conformance with the Accord Plan. review in the municipalities, and an of the steps that should be followed A Memorandum of Understanding established Technical Review for any site within the Accord among the Accord jurisdictions Committee comprised of County planning area. suggests that the panel departments and agencies for

5-2 / C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N B I G D A R B Y A C C O R D Department or Agency Development Issue review body. This body outlines the Board of Health On-lot septic systems process, provides initial feedback, answers questions and highlights Columbus/County Sanitary Regional sewerage treatment issues Engineers key issues or red flags. The technical reviewers should be County Engineer Roads, stormwater, public utilities, etc. capable of analyzing biological, Soil and Water Conservation District Stormwater, NDPES compliance hydrological and scientific Development Department (City or information and follow a Zoning, lot splits, subdivision plats, etc. County) development review checklist to Township Official Zoning ensure adequacy of plan information and detail, as described Figure 5.2 Technical Committee Roles in Planning Area in Section 5.2.2.

Jurisdiction Appointees Proposal Submitted City of Columbus An applicant desiring to rezone 3 (City Council and Mayor appointments) land for development or develop in City of Hilliard the planning area should submit an 1 (City Council and Mayor appointment) application to the appropriate Franklin County jurisdiction (county/township or 2 (Board of Commissioners appointment) city). The application will ensure Brown Township conformance to applicable criteria 1 (Trustee appointment) such as water quality monitoring, Prairie Township open space requirements, fees, etc. 1 (Trustee appointment) Pleasant Township Application Certified as Complete 1 (Trustee appointment) The application materials for Suburban Municipality zoning or site development are 1 (Grove City) reviewed by the local jurisdiction At Large for completeness in light of 1 jurisdiction and Accord Plan requirements. A complete Figure 5.3 Recommended Accord Panel Composition application is forwarded to the Big Darby Accord Advisory Panel. An 5.2.1 Zoning and Site general flow for zoning and site incomplete application would be Development Review Processes development approvals. held until all required materials are All applications for zoning, provided. subdivisions, minor lot splits, and Zoning applications should not site development within be considered without completing Jurisdiction Technical Review the Big Darby Accord planning this process, and plat or minor lot At a regularly scheduled meeting, area should follow this process. The splits should not be able to be the designated technical review process outlined for review is recorded, nor a building permit body reviews the details of all meant to address future issued, without completing this completed application plans for redevelopment and development process. The site development compliance with the Accord Plan efforts that affect land use change. process applies to all development and jurisdiction requirements. Staff It is not the intent of this Plan to applications that will result in the should have technical expertise and evaluate minor changes such as placement of habitable, non‐ be capable of analyzing biological, minor house additions, new agricultural structures. hydrological and other scientific porches, etc. The zoning and information. Review should development processes are Pre‐Submittal Meeting address environmental and described together due to It is recommended that any infrastructure requirements related significant overlap in steps. Where applicant with a proposed project to issues such as best management necessary for clarity, zoning and (zoning or site development) within practices, waste water treatment site development are articulated the planning area meet with the system, water quality monitoring, separately. Figure 5.4 depicts the jurisdiction’s designated technical development fees, required

B I G D A R B Y A C C O R D C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N / 5-3 Figure 5.4 Generalized Development/Zoning Review Process permits, open space, land use and 3) table the project at the request of Following development plan density, etc. Technical reviewers the applicant to allow provision of approval (Prior to Construction/ should follow a development additional information at a future Building Permit), final site plan review checklist. meeting. review and a construction monitoring plan must be approved. Jurisdictional Staff Review Recommendation The staff of the jurisdiction with Forwarded to Jurisdiction Final Site Plan Review authority over the project site The recommendation of the Big Following approval of the prepares a staff report for the Big Darby Advisory Panel meeting development plan, the final plan Darby Accord Advisory Panel. This would be forwarded to the should be reviewed for technical report should be based on appropriate jurisdiction for compliance by the local review recommendations and input from inclusion into the regular review committee to receive final the technical review body. The staff process in the form of a Record of certification and sign‐off that all report should be shared with the Action prepared by the attending conditions and requirements have appropriate staff of all Accord staff. This Record of Action should been met. This step may not be jurisdictions prior to the meeting. be shared with all Accord necessary if the final plat is in jurisdictions for their records. accordance. Alternatively, this step Big Darby Accord Advisory may necessitate the need for Panel Meeting Standard Jurisdictional additional review by the Big Darby All applications should be heard at Review Process Begins Accord Advisory Panel, pending a regularly scheduled meeting of Upon receipt of the the outcome of final plan review. the Big Darby Accord Advisory recommendation (Record of Panel. This Panel has non‐binding Action), the controlling jurisdiction Construction Site Monitoring review authority. This meeting follows its standard zoning review Plan Approved would be similar to a Planning process. Zoning submittals for land Prior to commencement of Commission meeting: public within the Accord planning area construction, all site protection and notices are sent in advance, the should not be considered by any monitoring measures should be Panel members receive the jurisdiction without the non‐ installed. These measures should be application and staff report in binding recommendation of the Big reviewed and approved on‐site by a advance, the responsible Darby Accord Advisory Panel. designated Chief Building Official jurisdiction staff makes a Final legislative authority for the and/or technical expert. presentation at the meeting, the zoning continues to rest with the The final step before an occupancy applicant is heard, public appropriate city Council or Board permit can be issued involves an comments are invited and the Panel of Commissioners. Following final approval process involving a post votes on a recommendation for the legislative action, a notice should be construction review. project. The Panel has three sent to all the Accord jurisdictions options: 1) recommend the project and the Darby Accord Advisory for approval with any conditions, 2) Panel indicating the action taken. recommend denial of the project or

5-4 / C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N B I G D A R B Y A C C O R D Prior to Occupancy Permit Site Investigations intended improvements to those Post‐Construction Review Site investigation information transportation corridors represented All Best Management Practices should identify areas within the by the Accord Plan or other planning (BMPs) required as part of the site, such as the stream setback documents associated with the approved plan should be certified areas and conservation open space individual jurisdiction where the by a technical expert. If that could be part of an easement or project resides. discrepancies are detected, an as‐ land dedication. built plan should be required of the 1. Soils Preliminary Site Planning developer and any issues resolved • Determine the location of hydric soils 1. Establish open space commitment prior to issuance of an occupancy within the site, based initially on the within the development site. The permit. Construction and post‐ published Franklin County Soil open space commitment should be construction water quality samples Survey Maps. On‐site investigation of determined based on the ability of the should be provided. soils may be necessary to clarify the site to preserve and enhance the extent of hydric soils and sub‐surface existing environmental conditions. 5.2.2 Detailed Review Process investigations may be necessary to • For Conservation Development A more detailed review process is determine the suitability of soil areas, the open space commitment described below to provide an conditions for later evaluation of must be equal to or greater than understanding of the level of detail stormwater BMPs applications. 50% of the land area dedicated to that will need to be part of any site the development site. development proposal in the 2. Environmental Conditions • For all other sites, establish areas planning area. • Identify existing topography and for parkland dedication in contours. accordance with the requirements Step 1: Preliminary Site Approval • Delineate the location of all of the Accord general land use The first step of the process should jurisdictional streams within the plan or other planning documents establish the suitability of the site limits of the project site, including all associated with local jurisdiction. for development in accordance with ephemeral, intermittent and • For wetlands to be preserved the Big Darby Accord Plan. The perennial streams, identifying each within the site, delineate the buffer developer should provide due watercourse by this classification area in accordance with the criteria diligence aimed at understanding system. Also identify and map within ODNR’s Rainwater and Land the constraints of the site related to existing drainage patterns on site and Development (draft) document. existing environmental conditions. determine and map the extent of the • Identify preliminary planting plan Information collected during this SCPZ. and management plan for all open process should be used to make • Delineate the location of all space areas including easements. informed decisions regarding the jurisdictional wetlands. appropriate utilization of the • Identify existing tree cover on site 2. Depict conceptual lot and roadway property balanced with the need to and delineate large (greater than 3 alignments within the development protect environmentally sensitive contiguous acres) wood lots within site. areas. This step would result in the the limits of the project site. • Where low‐impact development developer submitting a site • Delineate critical groundwater standards are to be applied, development layout identifying recharge areas and pollution potential demonstrate noted exceptions to areas of conservation and zones (information established by the current zoning ordinances, development, accompanied by the ODNR’s DRASTIC mapping is an planning policies and/or supporting technical acceptable resource for this subdivision regulations. documentation as described below. information). • For wetlands proposed to be filled, A complete site investigation provide information regarding should consider extending beyond 3. Existing and Future Infrastructure mitigation alternatives to be the development site area to • Identify the location of existing considered during the anti‐ identify contributing resources on utilities and their respective degradation process. adjacent lands. easements. • Depict and describe all proposed • Identify all existing road rights‐of‐ development activities that way impacting the project site. The constitute permitted and delineation of roads and their rights‐ conditional uses associated with of‐way should include a reference to the SCPZ. any available information depicting

B I G D A R B Y A C C O R D C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N / 5-5 3. Provide information regarding water Step 3: Permitting and Compliance EPA will issue a permit directly to the and sewer service for the site. Prior to the start of construction, project (site) owner and will request • For the portions of the land use evidence of permits for all activities that the contractor performing the site planning area designated as the related to the site should be work submit additional Town Center or within the City of provided to the jurisdiction within documentation as a co‐permittee. Hilliard’s designated contract which the development site resides. • Permit‐to‐Install (PTI): A filing must sewer service area, sewer will be Additional information regarding be made to the Ohio EPA that provided through a central relevant permits is described below. includes engineering plans related to collection system. The preliminary • Environmental Permitting: A any component of the project that site development plan must nationwide 404 permit from the U.S. includes the construction of sanitary indicate the intentions for and the Army Corps of Engineers, or sewer systems to extend an existing ability to connect to that system. individual 401 Water Quality central sewer system. The Ohio EPA • For other development sites within Certification from the OEPA and a requires that all such plans bear the planning area, where central 404 permit are required for all evidence of review and approval by sewer is not provided, the sewer is proposed impacts to jurisdictional the governing jurisdiction where the intended to be provided through waters if the U.S., including filling of sewer is to be installed, prior to their community‐based alternative streams and wetlands. All such review and approval of those plans. treatment facilities. Again, the activities must be done in accordance The City of Columbus will also be preliminary site development plan with the established provisions of the signatory to any sanitary sewer must indicate the intentions for Accord. Given the complexity and plan approvals that involve an and the ability to connect to that time consuming nature of this extension of or connection to the system. permitting process, the Accord may central sewer systems that will • If on‐lot septic systems are consider allowing for a discharge to the City. proposed, then the preliminary site demonstration that this process is • Building Permit: individual development plan should be substantially complete when jurisdictions may have different accompanied by evidence of approving development. processes related to issuing building coordination with the Franklin • Floodplain Permitting: A Special permits for individual structures or County Board of Health in Flood Hazard Area Development other aspects of a site development. determining the suitability of the (SFHAD) permit is required from the The Accord should defer to and site to that approach. governing jurisdiction when any maintain those processes. grading activity (fill or excavation) is Step 2: Site Design Process proposed within a FEMA‐designated The compliance process represents After completing preliminary flood hazard area. Again, all such the last step prior to the planning for the site, the next step activities must be done in accordance commencement of construction. for site development requires a with the established provisions of the Evidence of the relevant permits functional layout and design that Accord. For certain activities affecting should be readily available for incorporates the conservation a FEMA‐designated floodway and inspection at the construction site, principles represented by the Darby where those activities would cause an in anticipation of site visits from the Accord. This includes developing a increase in flood elevations, prior various regulatory agencies or the suitable approach for stormwater review and approval of the activity Big Darby Accord Advisory Panel. management and meeting the are required from FEMA. It is also recommended that each water quality standards through • Notice of Intent (NOI): A filing must jurisdiction establish a reliable implementation of BMPs. The result be made with the Ohio EPA with repository for permits issued to of this process would be the sufficient advance notice prior to each development. Such a submission of engineering beginning earth moving activities repository is mandated for all documents, including a that will disturb an area larger than SFHAD permits under the comprehensive stormwater 1.0 acre. The submission of an NOI jurisdictions’ participation in the management report, detailing all of must be accompanied by a National Flood Insurance Program. the features of the site as well as Stormwater Pollution Prevention management plans for identified Plan (SWPPP) as prescribed in the Step 4: Construction Phase easements. statewide NPDES permit (refer to the Once all permits have been permit being developed specific to obtained, site work may begin. The construction activities within the Big provisions of the approved SWPPP Darby Creek watershed). The Ohio should be implemented to ensure

5-6 / C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N B I G D A R B Y A C C O R D that erosion and sediment control analyzed. Monitoring information is • Surface Waters practices are in place prior to to be collected and provided to the • Drainage Patterns beginning any significant earth‐ Accord in accordance with the • Wetlands moving activities. Provisions for provisions discussed in Section 5.3. • Floodplains compliance with criteria related to • Evidence of a performance bond that • Stream Corridor Protection Zones monitoring and testing stormwater will be maintained throughout the • Ephemeral, Intermittent and runoff from development sites must prescribed site‐level monitoring Perennial Streams be accounted for. The performance program. • Subwatershed boundaries goal for the monitoring of • Water Quality of Streams (based on stormwater runoff during the Only once the required information OEPA Use Attainment) construction phase of a project is has been provided to the Accord • Significant Habitat (land and water prescribed by the Ohio EPA in the should the developer be allowed to based, including any listed species ) draft NPDES permit for the Big begin the one‐year warranty period • Topography Darby Creek Watershed. for the public improvement • Wooded Areas portions of the project. • Soils Site water quality monitoring • Field Tile during construction is not part of 5.2.3 Development • Historical and Cultural Resources the monitoring program proposed Review Checklist • Open Space or Natural Areas by the Accord; however, evidence To facilitate coordinated review • Recreation Resources or Community of non‐compliance with the and consistency, two review Facilities (adjoining properties) established performance goal checklists should be developed for • Stormwater Management Facilities should result in a course of action both technical review and Accord (on site and on adjoining properties) by the Accord to ensure that Advisory Panel review. • Steep Slopes appropriate remediation action is • Existing Wells and Septic Systems taken. The first development review (adjoining properties) checklist should be adopted by • Easements Planting and Step 5: Post‐Construction Phase Accord jurisdictions and used Management Plan Upon completion of the consistently by all staff as part of • Monitoring Program construction of the development technical review efforts in each site (or individual phases of the jurisdiction. Components of the The Accord should also consider development), the items listed technical review checklist should incorporating Low Impact below should be provided to the address plan requirements related Development concepts into the local jurisdiction and the Big Darby to polices, standards and checklist to identify opportunities Accord Advisory Panel by the regulations. for incorporating such techniques developer. into the design process. It is • An as‐built survey of the various It is important that both developers important that the development components of the stormwater and reviewers consider the review process facilitates the management system. The submitted surrounding environment of a site application of low impact material should verify that these and that development plans are not development techniques and does components were constructed to prepared in isolation. This concept not make it more difficult to within an acceptable tolerance in is important to promote implement LID principles. For terms of elevation, area and volume. connectivity to existing resources example, requirements for lot For projects that vary from this such as natural or open space areas dimensions, parking, driveways tolerance, the developer may submit and to understand how activities at and roadway standards should necessary calculations to determine one site are part of an overall offer flexibility and not become that the stormwater management ecosystem. Early and frequent obstacles to applying LID system will still function as needed; discussions between the local principles. otherwise, physical modification to jurisdiction and developer should the system may be required. identify any opportunities to In addition an Accord Plan review • Evidence of implementation of the connect with adjacent or nearby checklist should be developed to site‐level monitoring plan, amenities. A development review help the Accord Advisory demonstrating the responsible party, checklist should ensure the Committee in its review. The and the means and methods by which identification and/or mapping of checklist is less about technical information will be collected and the following elements: aspects of each development and

B I G D A R B Y A C C O R D C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N / 5-7 more about compliance with the 5.3 Other pollutants of concern as defined by overall goals of the Accord Plan. Coordinated Activities the TMDL. Appendix D provides an example of a preliminary Accord Advisory To initiate implementation of the Watershed Level Monitoring Panel review checklist. Plan, the Accord will need to also A two‐tier watershed approach is coordinate activities related to recommended with the tiers having Measuring Plan Progress establishing a monitoring program, different objectives in verifying the Monitoring overall conservation developing a Town Center Master health of the ecosystem of the efforts and development activity Plan, and providing adequate planning area. The purpose of Tier I across jurisdictions will be community facilities as addressed monitoring is to determine that the necessary to understand how the below. Ohio EPA’s aquatic life use plan is being implemented and designations for Hellbranch Run, what, if any, changes are needed to 5.3.1 Monitoring Clover Groff Run and Hamilton ensure the plan is still meeting the To ensure that the integrity of the Run are being attained, or at a mission of the Accord. To assist in water quality within the portion of minimum are trending towards this effort, the Accord should the Big Darby Creek watershed attainment. The purpose of Tier II develop a method for tracking affected by the Accord land use monitoring is to establish a cause development that documents the plan does not decline due to and effect relationship between on‐ number of units built across implementation of the land use going land use changes and jurisdictions so that reports can be plan, monitoring of water quality observed biological indices within generated on overall development. parameters will need to be the stream system. The two‐tiered In addition, information related to implemented throughout the approach is described below. successful conservation efforts planning area. The purposes of the should be recorded. Reporting and monitoring program should be to Tier I entering this information into a determine whether or not the Monitoring at the Tier 1 level is centralized system should be part OEPA aquatic life use designations envisioned as a long‐term effort of the development review for the streams in the planning area and, therefore, has no defined end checklist requirement. are being met and to gather enough date. Tier 1 monitoring points data to develop meaningful trend should be located in the Hellbranch The Accord jurisdictions should analysis of the health of the Run Watershed and along the Big work with the County to develop watershed. The monitoring Darby Creek. an approach for the centralized program should be utilized to more tracking of development and precisely determine where water In some cases a geomorphic conservation activities. Yearly quality degradation may be assessment is recommended which reports about development activity occurring and the likely source of is a collection of specific physical will help local officials and the that degradation. Monitoring will parameters defining the stream public understand the relationship allow for a timely response to channel, including cross‐sectional between policy and the plan and potential problems before they have data at pools and riffles, a will identify any inconsistencies a long term impact on the health of longitudinal profile and a pebble between local actions and plan the stream. count (a statistical measurement of recommendations. substrate). A thorough geomorphic The recommended monitoring assessment must make note of any The Big Darby Accord Plan program involves both watershed physical evidence of a bank‐full should be updated every five to level and development site level indicator, such as forming bank‐full ten years. The Plan update should monitoring. The primary purpose benches or other abrupt change in include a map update, policy of the watershed level monitoring is the cross‐section of an incised review an overall evaluation on to ensure that the aquatic life use channel, changes in point bar development and conservation designations for all reaches of the composition (bed load indicators) efforts and updated stream are being met. The primary and the overall stability of the implementation strategies. purpose of the development site channel banks. The assessment level monitoring is to ensure these sites are not exceeding determined should comprise a length of stream allowable release rates for channel that is between 20 and 30 times the measured (or anticipated)

5-8 / C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N B I G D A R B Y A C C O R D bank‐full width of the channel. Big Darby Creek Monitoring Points At other sites that fit the purposes As part of this assessment, it is Just upstream and just downstream of the type of monitoring (exact recommended that permanent of confluence with Little Darby locations to be determined) markers be installed at each cross‐ Creek: necessary to establish experimental section location to allow for • IBI, ICI, and QHEI once every and control levels of data. comparison of the physical features three years • TSS, P, and N based on flow at the sites from observation to characteristics, probably 3 or 4 observation. At three sites near the confluence times a year • Geomorphic assessment of stream with Hellbranch Run; just in year 1 and year 3 Hellbranch Run Watershed upstream, just downstream and

Monitoring Points along Gay Run just upstream of its Development Site Level Monitoring At the USGS gage for continuous confluence with Big Darby Creek: The purpose of site level flow monitoring: • IBI, ICI, and QHEI once every three years monitoring is to determine whether • USGS provides monitoring of or not site level (or regional) BMPs TSS, N, and P • Geomorphic assessment (defined The next two sites are optional as are meeting their targeted pollutant below) of the stream in the vicinity of they are indicators of what is removal rates, and that pollutant the gage once every three years occurring within the overall Big rates are not exceeded. The Darby Creek watershed, but recommended monitoring period Just downstream of the confluence outside of the Big Darby Accord for site level data is for at least five of Hamilton Run and Clover Run: planning area. The information years, but no more than ten years. • Flow monitoring they would provide is potentially • TSS, N, and P during high‐flow useful in determining the source of Locations for data collection events between March and October any impairments to water quality, if include outfalls of all new • Will likely require an automated stormwater conveyance systems. sampling device they exist. An automated sampler will be • Geomorphic assessment of the stream once every three years At the county line where Big Darby required at the outfall of the Town Creek enters Franklin County (2 Center conveyance system and all At 14 of the established EPA actual locations): other regional conveyance systems. monitoring sites as well as 4 • IBI, ICI, anf QHEI once every Grab samples should be gathered at additional locations: three years all other outfalls. • IBI, ICI, and QHEI once every three years At the county line where Little In addition, monitoring for TSS, P, • Geomorphic assessment once every Darby Creek enters Franklin and N should take place a three years County: minimum of twice per season ‐ • IBI, ICI, and QHEI once every once during a dry period (no Along McCoy Ditch near the three years precipitation for three days), once confluence with Hellbranch Run: during a rain event of 0.75 inches in • IBI, ICI, and QHEI every year for Tier II 24 hours and as needed during three years (to establish a baseline), Monitoring at the Tier II level other rain events. then once every three years should be collected for a minimum • Geomorphic assessment of the stream of three years and will require once every three years A summary of monitoring automated monitoring equipment recommendations is shown in (i.e. ISCO samplers). Tier II data Figures 5.5 and 5.6. gathering locations are described below.

At half of the established OEPA monitoring sites TSS, P, and N based on flow characteristics, estimated to be 3 or 4 times a year • Geomorphic assessment of stream in year 1 and year 3

B I G D A R B Y A C C O R D C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N / 5-9 Location Data Gathered Time Period End Date USGS Gage Flow, TSS, N, P, Flow-continuous Geomorphic TSS, N, P-at least once per month Geomorphic-once every three years D/S confluence of Flow, TSS, N, P, Flow, TSS, N, P-high flow events March-October Hamilton and Clover Geomorphic Geomorphic-once every three years Groff 14 EPA sites and 4 IBI, ICI, QHEI, Once every three years others Geomorphic Hellbranch Run McCoy Ditch near IBI, ICI, QHEI, IBI, ICI, QHEI-every year for three years, then once Hellbranch Run Geomorphic every three years Geomorphic-once every three years Just U/S and D/s of IBI, ICI, QHEI Once every three years confluence with Little Tier I Darby Creek Just U/S and D/S of IBI, ICI, QHEI Once every three years Hellbranch Run and No defined end date along Gay Run just Big Darby Creek U/S of Big Darby At county line where IBI, ICI, QHEI Once every three years

Watershed Level Monitoring Big Darby Creek enters Franklin County (2 locations)

Optional At county line where IBI, ICI, QHEI Once every three years Little Darby Creek enters Franklin County Half of OEPA TSS, P, N, TSS, P, and N-based on flow characteristics, likely Established sites Geomorphic 3 or 4 times per year Geomorphic-once every three years Area years Tier II Other sites, to be TSS, P, N, TSS, P, and N-based on flow characteristics, likely Planning

determined Geomorphic 3 or 4 times/year Minimum 3 Geomorphic-once every three years Outfalls of all new TSS, P, N Minimum of twice per season stormwater -once during dry period (no precipitation for three conveyance systems- days) automated at Town -once during rain event of 0.75 inches in 24 hours Center and other -as need during other rain events

Site Level regional systems, grab Monitoring Minimum 5 than 10 years Planning Area

samples at other years, no more outfalls

Figure 5.5 Summary of Monitoring Recommendations

Rainfall Monitoring which is the threshold for gathering Data guidelines. Level 3 data is In order to more accurately data. If the gauges are to perform equivalent to the methods used determine when water quality this function, they will need to be by the Ohio EPA personnel and is sampling is needed, a system of tipping‐buckets gauges that can the only level of data that is able to rain gauges is recommended within transmit their information to a be used for regulatory purposes the planning area. It is anticipated remote location for observation. by the Ohio EPA. that approximately 18 rain gauges will be needed, with the exact Data Collection Requirements Any monitoring data collected number and location to be To meet the legal standard for should comply with the most recent determined. The information from establishing aquatic life use OEPA requirements of the Credible the gauges would be used by those designation, Tier I data should Data Program as outlined in Ohio performing the sampling of water comply with the OEPA Level 3 Administrative Code Chapter 3745‐ quality data to determine when 0.75 data as established under the Ohio 4, effective March 24, 2006. inches of rain has fallen in 24 hours, EPA’s Volunteer Monitoring Monitoring of additional

5-10 / C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N B I G D A R B Y A C C O R D parameters beyond those listed locations for the rain gages and determined. The bond could be should be conducted on an as‐ monitoring locations. executed under any one of the needed basis. Additional following circumstances; monitoring locations will be The EMG should also assist with 1. Submitted monitoring data incorporated as development developing consistent guidelines indicates that the BMP is not occurs and as conditions warrant. for stream restoration that can be meeting performance goals. 2. Submitted maintenance logs indicate used by local jurisdictions to that maintenance is not being As data from the monitoring evaluate stream restoration performed as outlined. program are compiled and proposals that are part of 3. Monitoring data is no longer analyzed, it should be utilized to development plans. Guidance from being provided by the developer review the development the EMG could include developing and the EMG must continue the requirements and determine goals and priorities related to monitoring program. whether or not changes need to be where stream restoration should 4. Maintenance records are no longer made to stormwater management occur and developing being provided by the developer requirements for water quantity or recommendations on preferred and the EMG must continue the maintenance program. quality. design criteria for stream

restoration applications. The bond should be released to the Partnerships should be developed developer once the required between the Big Darby Accord and The EMG should produce a “State monitoring period outlined above other organizations (e.g. The Ohio of the Darby” report every two to has been completed satisfactorily. State University, Ohio EPA, Ohio five years to report on water quality

DNR, Franklin Soil and Water trends within the watershed Hellbranch Watershed Forum Conservation District and others) to compared to the TMDL and Plan The Hellbranch Watershed Forum obtain the necessary monitoring goals. This report should state (HWF) also developed monitoring data for the watershed level concerns and identify any guidelines for the Hellbranch program. Site level monitoring data recommended action for mitigating watershed and a summary of their gathering is the responsibility of the impacts. recommendations is presented developer for the site, and it also below. The purpose for the HWF must comply with Ohio EPA’s Monitoring Funding Options monitoring is “…to measure the Credible Data Program. A The USEPA Targeted Watersheds changes that occur in the watershed developer could also rely on Grant Program is a competitive and assess the impacts of those another organization to gather and grant program that encourages the changes on the streams. The interpret data from their site as long protection and restoration of the monitoring program results will be as it complies with the applicable country’s water resources. The used to evaluate the effectiveness of requirements for monitoring of the program supports environmental management strategies designed to planning area. stewardship and action by protect and enhance the watershed providing needed funding to and to identify emerging issues Environmental Monitoring Group watershed organizations for on‐the‐ including: The Accord should establish an ground restoration and protection • What are the effects of watershed Environmental Monitoring Group efforts designed to achieve quick, improvements? (EMG) to assist with developing a measurable environmental results • How have land use changes affected comprehensive water quality (www.epa.gov/owow/watershed/in the health of the watershed? monitoring program for a itiative). Other funding sources • How have policy changes affected the watershed. Initially this group may be available through potential health of the watershed?” should include The Ohio State partnering groups including OSU, University, Ohio EPA, ODNR, Ohio EPA, Ohio DNR, FSWCD, the In order to meet the purposes of the Franklin Soil and Water Nature Conservancy and others. HWF monitoring program, they Conservation District and one Performance Bond recommend reviewing Franklin outside environmental interest Site developers should provide County Auditor aerial photography group (e.g. The Nature proof of a performance bond for all of the watershed to determine what Conservancy). The EMG should new development occurring within land use changes have occurred. In assist in identifying the final the planning area. The amount of addition to the land use changes, the bond will need to be the HWF recommended in stream

B I G D A R B Y A C C O R D C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N / 5-11 Figure 5.6 Water Quality Monitoring Program monitoring at the 10 OEPA sites that were used in the development of the Biological and Water Quality Study of the Big Darby Creek Watershed and Selected Tributaries, 2001/2002.

The in‐stream monitoring recommended by the HWF includes biological health, habitat quality, flow and chemical water quality, all occurring annually in accordance with OEPA CDP Level 1 requirements. Habitat monitoring was to utilize QHEI; flow monitoring was to occur using the Travel‐Time Method at locations other than the USGS gage and occur at the same time and locations as the QHEI scoring. For biological monitoring, the HWF suggests partnering with the ODNR Ohio Stream Quality Monitoring (SQM) Project to gather Level 1 data at many of the sites referenced above, as ODNR indicated they would not be able to assist with all of the sites identified. Water quality data recommended to be gathered includes pH, temperature, dissolved oxygen

5-12 / C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N B I G D A R B Y A C C O R D and specific conductance as they The following section provides a jurisdictions they should also be can all be gathered using probes detailed description of these involved in identifying the shortlist or test kits in accordance with elements. and preferred team for the project. Level 1 data. The team should have a range of Step 1: Organizing Key skills and demonstrated excellence 5.3.2 Town Center Master Plan Stakeholders and Sponsoring related to land use planning, One of the key recommendations of Organizations environmental planning, urban the Big Darby Accord plan is the A committee or task force should be design, engineering, transportation, preparation of a detailed master established that includes a diverse and market analysis. plan for the town center area as cross‐section of stakeholders. This identified within the general land group should include: Step 3: Preparation of the use plan. This area generally falls • Private Property Owners Master Plan between I‐70 on the north, West • Jurisdiction Representatives Once a consultant team has been Broad Street on the south, the • Environmental Interests contracted, the committee and Hellbranch Run on the east and • Real Estate/Development Interests consultant team should work Hubbard Road on the west. This closely in developing the master plan would help establish a more The goal of this committee would plan. This process should include a specific vision for the development be to establish a process and significant amount of community of the Town Center and would schedule and to help define the involvement and individual provide a detailed set of final scope of work and required stakeholder involvement. The recommendations including level of level of expertise and skill sets master plan should include the development, infrastructure needed to perform the work. This following key elements: requirements, design guidelines group may also be involved in and phasing. A Master Plan of this determining the approach to how Existing Condition Analysis type would require approximately to fund the study. Once these basic This includes more detailed one year to complete and should elements are agreed upon, a analysis of the physical conditions include a number of key Request for Proposals (RFP) Process of the area including natural stakeholders in the process. The should be initiated. This should be resources, infrastructure, roadway master plan should address not sponsored by one of the systems, existing development, and only the public and private jurisdictions; similar to how the any other physical features. properties within the Town contract for the Big Darby Emphasis should be placed on Center but it should also Accord operated. documenting sensitive incorporate the adjacent areas as environmental features. part of the study. This will help Step 2: RFP Process to Select ensure the town center Consultant Team Current Plans and Policy Review complements and is compatible The RFP process would include This includes more detailed review with the surrounding areas. releasing the RFP, reviewing of existing zoning and previously responses to the RFP, interviewing prepared studies that address the A number of steps are required in a short listed group of firms and area (including local, state and the preparation of the master plan. identifying the preferred team. The federal studies). At a minimum Brown and Prairie RFP would include background Townships should lead the Master information on the project, a Summary of Key Opportunities Plan effort, in coordination all suggested scope of work, schedule and Constraints members of the Accord, and identify the key stakeholders. As a summary of the physical particularly the City of Columbus The RFP should require that analysis and review of plans and due to utility provisions. Process respondents provide qualifications policies a summary is prepared to steps include organizing the on their firm or firms, key team identify key issues, opportunities stakeholders/sponsoring member resumes, skill sets and and constraints for development organizations prior to beginning experience, a proposed project within this area. the process, identifying a team to approach and scope and a prepare the master plan, proposed fee. The responses to the Case Studies preparation of the master plan and RFP should be reviewed by a It may also be useful to prepare a implementing the master plan. committee or subcommittee brief set of case studies illustrating representing the stakeholders and other comparable town centers

B I G D A R B Y A C C O R D C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N / 5-13 within Central Ohio or around the based solely on one of the addresses number of lanes required, U.S. This should include pictures alternatives. This plan should again and intersection improvements. In and illustrations to help everyone be reviewed by stakeholders and addition, the transportation plan understand the physical the community. should address other modes of development options for a town movement including trails and center. Emphasis should be placed Supporting Master Plan Elements pedestrian systems. The plan should on communities that incorporate Once a preferred plan is identified, identify appropriate locations for low‐impact development a number of supporting plans these elements and suggested widths techniques and other innovative should be prepared to provide key for sidewalks. design. guidance in the ultimate • Stormwater Plan development of town center. A Stormwater Plan identifies Market Study • Development Program appropriate locations and types of A detailed market study is A development program includes a stormwater treatment based on the recommended to provide some recommended range of development proposed land use plan. This plan parameters for the level and by type of use. This includes number addresses both the physical amount of development that could and type of residential units, retail requirements as well as the treatment be expected over a period of time. uses, commercial uses, institutional level requirements to ensure the This study should provide an uses and other supporting uses. development is meeting water quality expected range in the number and This program includes a geographic goals stipulated in this Plan and types of housing units that could be representation illustrating the per OEPA. constructed and forecast level or range of development to • Design Guidelines development demand measured in occur on a block by block basis within Design Guidelines provide square footage, unit type and town center. recommendations for the physical business type for five and ten year • Land Use Plan development of the town center for increments. The market study A Land Use plan is a block by block both public and private areas. The should also provide a range of level plan that provides detailed land design guidelines include pricing that could be expected for use recommendations. This also architecture, site planning, the various uses. includes specifics regarding streetscape, landscaping and parks recommended first floor uses within and open space recommendations. Town Center Alternatives the mixed‐use areas. Guidelines are largely graphic in Based on the physical analysis and • Open Space Plan content illustrating the concepts for market study, a series of An open space plan provides a the physical development. alternatives should be prepared for framework for open space, • Phasing Plan the town center. These alternatives illustrating appropriate locations for A phasing plan is linked to the could address both program and the various types of open space market analysis, infrastructure site planning variations. including natural areas, wetlands, availability and land ownership. The Development and evaluation of urban parks, neighborhood parks and phasing plan establishes a reasonable these alternatives should include passive recreation areas. This also expectation of the timing for the public involvement either in a provides program recommendations development. workshop or meeting format. The for the park areas such as • Regulatory Plan alternatives should include a playgrounds, ball fields, trails or A regulatory plan addresses any program summary, a site plan and other appropriate uses. recommendations regarding zoning, supporting diagrams and • Infrastructure Plan density, land use, building heights. illustrations that help describe the An infrastructure plan addresses This plan provides the jurisdictions ideas behind each alternative. anticipated sewer and water detailed recommendations that could requirements, how these might be be incorporated into the jurisdictions Preferred Town Center Master Plan provided and the timeframe for zoning or other regulatory Once the Alternatives have been providing this service. requirements. sufficiently reviewed and • Transportation Plan • Draft and Final Master Plan Report commented on by the stakeholders A transportation plan provides a The Master Plan and supporting and community, a preferred Master recommended road network to elements should be documented in a Plan is to be prepared. The support the town center along with report. The preparation of the report preferred Master Plan may include specific improvements required for includes a draft report for review and elements of each alternative or be the existing roads. This plan a final report incorporating the

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comments on the draft plan. The Fire Protection Average response time of 5 minutes or less; report should be highly graphic and Average of 0.85 firefighters per 1,000 residents. avoid extensive sections of text. Police Protection Average of 2.3 officers per 1,000 residents Step 4: Implement Master Plan Once the Master Plan has been Parkland 10 acres per 1,000 residents completed, the jurisdictions will need to adopt the necessary policy Libraries 0.5-square feet per capita; changes to implement the plan. In At least 3 books per capita; addition, the jurisdictions and Within 5 miles of a facility stakeholders should work closely with the property owners and Childcare 2.5 providers per 1,000 residents development community to move the plan forward and enable Figure 5.7 Community Facility Level of Service (LOS) Considerations development to begin. It will be critical that property owners are willing to cooperate in this process Jurisdictions should work together and facilities should demonstrate to ensure a smooth process for to consolidate facilities (schools, excellence in architectural design. development. libraries, post offices, parks) to

create focal points of activity As the area grows and attracts new 5.3.3 Community Facilities whenever possible. This will be residents, local leaders will need to As growth continues in the Darby especially important for the Town respond to changing demographics. Accord area, jurisdictions must be Center to foster community Therefore, community facilities mindful that this growth will interaction and congregation. The should be flexible in function to require additional facilities and Accord process has created ensure adaptability to the changing expanded service areas. increased opportunities to share needs and demographics of the Jurisdictions should use the Accord amenities that would not otherwise Accord area. Plan and land use maps as a guide be feasible on an individual for community facilities decisions. jurisdictional basis. This can extend Level of Service The Accord Plan should give from basic functions such as A level of service (LOS) should be insight to areas that will need grounds keeping and maintenance, established by all jurisdictions future services and facilities. trash collection and recycling to within the watershed in Franklin

more specialized amenities such as County. The level of service that The provision of the basic health, recreation centers, senior centers should be pursued is described safety and welfare services is and community pools. Joint below. necessary, including reasonable contracting opportunities should be access to health, education, encouraged throughout the Town Center Community Facilities recreation, police and fire planning area and with The proposed Town Center will protection, library and postal surrounding jurisdictions. have a greater demand for services services. These services provide for than the other parts of the Accord a high quality of life for those living The development practices of area (police, fire protection, social, and visiting the area. As community facilities, particularly healthcare and recreation), due to development is planned and public buildings, should set an concentration of residents. constructed, service areas should be example for other developments However, the development pattern evaluated and established for within the Big Darby Creek and density provided will allow it various community facilities such watershed. Jurisdictions should be to be served very efficiently, as schools, parks, libraries, fire, encouraged to go beyond standard maximizing the serviceable area. police and emergency response practices and incorporate With cooperation between all services. Equally important, sustainable building techniques jurisdictions, resources should also adequate funding and phased such as those designated by the be shared. Recommendations for delivery of service must be U.S. Green Building Council future community facilities and considered. (LEED). The design and services for the Town Center are

construction of public buildings outlined below.

B I G D A R B Y A C C O R D C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N / 5-15 • Each jurisdiction should evaluate its Parkland Requirements Accord jurisdictions should, current service capabilities for police, Parkland requirements and level of likewise, provide flexibility in fire and medical response in order to service standards vary within the meeting parkland requirements. gauge existing response times and planning area. It is recommended Both Columbus and Hilliard coverage areas. Initial development that the Accord jurisdictions adopt maintain that if there are a number of phases in the Town Center should level of service standards for of constraints in which a parkland utilize the existing services and parkland of 10 acres per 1,000 dedication cannot be made, a fee‐ facilities until further expansion is residents to anticipate future in‐lieu (based on a determined fee required. A Town Center Master Plan growth and demographic changes or appraised value of the market should address long term community and evolving trends in recreation. value of land area) is acceptable. facilities needs. The City of Hilliard has both open • As service demands for the Town space and parkland dedication Rural Residential Center increase, new facilities should requirements for residential Community Facilities be properly located and service areas developments. In addition to The proposed rural residential re‐districted to maximize the requiring that 10% of the gross land areas are intended to be developed populations and areas served. to be developed be set aside within as clustered developments. This • Cooperative agreements between the the residential development, pattern of development will bring township jurisdictions should be Hilliard requires a land dedication with it unique challenges to formulated to share health and safety for recreational facilities intended community facility administration services. Existing contracts for health to serve the greater population of (police, fire protection, social, and safety services such as those the City. The City of Hilliard has healthcare and recreation). established with the County Sheriff adopted a goal of providing 10 Although the population will be should be expanded upon as needed. acres of usable recreational land for less than what is intended for the • Provision of services within the Town every 1,000 residents. town center, this area will increase Center could be financed through the in population from its current level Community Authority. The In the City of Columbus a which will require more services. Community Authority should have dedication for parkland is required To be effective in a lower density the right to subsidize jurisdictions for either through a land dedication or area, the community facilities must the provision of services that is the a monetary payment and is applied be properly sited not only to be most economically feasible. The to both residential and commercial effective, but also efficient. Community Authority should serve zonings. The City of Columbus has as an advisory body to those entities an overall goal of providing 5.5 Fire Services providing protection services. acres of land for every 1,000 Currently the Fire Services in the

residents. Parkland dedication townships are addressed by Pleasant A number of facility amenities credits may be granted for a Township Fire Department, would be appropriate for the Town number of circumstances and are Prairie Township Fire Department, Center in order to promote civic determined by the recreation and Norwich Township Fire Department identity, create interaction between parks commission as appropriate: and Washington Township Fire residents and help spur • Credit may be given for private Department (Brown Township surrounding business patronage. outdoor recreational facilities contracts with Norwich Township These include: provided in residential and provides a Fire House in Brown • Community recreation center developments. The maximum credit Township that is staffed by Norwich • Public pool is 50% the required land dedication. Township Fire Fighters).

• Senior center • In the event that a wet storm water retention area is proposed to be • Youth Activity Center Mutual aid agreements between the dedicated, it can constitute no more • Active Recreation Fields (ball fields, townships and the municipalities than 25% the dedication requirement. multi‐purpose fields, courts, etc.) • Credit shall be given for previous should be reviewed to ensure the • Fire station land dedications for land to be quality of Emergency Services in not • Neighborhood police sub‐station rezoned from one residential impacted by the increase in • Public meeting hall/auditorium classification to another residential population. • Branch library classification based on the • Schools incremental increase in density. • Health center

5-16 / C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N B I G D A R B Y A C C O R D Without centralized water, rural Schools Hilliard City Schools residential areas would be without The two primary school districts The Hilliard City School District is the hydrant infrastructure to assist in located within the Franklin County experiencing rapid enrollment fire fighting. Therefore, all new portion of the watershed are the increases as the district continues to developments within the rural Hilliard School District and the post strong residential growth. The residential areas should provide Southwestern City School District. district grew from 9,949 students in amenities to assist township fire 1995 to 14,530 students in 2005 and it services. These amenities may include The school district boundaries meet now has the 9th largest enrollment in dry hydrants with the necessary at the railroad tracks between the state. District officials expect the easements of access for each Interstate 70 and Broad Street in the school population to increase at a rate subdivision. middle of the proposed town of 300 to 400 students per year and center. project enrollment of nearly 19,000 Police Services students by 2015. Currently all five townships within Win‐Win Agreement the watershed do not maintain their The land developed as part of the Recently the district residents own township polices service. The town center is intended to remain in approved a new levy to fund a third Franklin County Sheriff’s Department the township and will not be annexed high school. The site for the third provides patrol services for the to Columbus. This means that the high school is located on Walker Townships with dedicated officers residential units built there would not Road in Brown Township. The two assigned to contracted areas. become part of the Columbus City existing high schools house 4,350 Schools; students would remain in students with capacity for only 3,600. With the increase in population in the suburban school districts as the western Franklin County the boundaries are currently drawn. In the Accord area the City of Hilliard dedicated patrol hours will need to be has an expansion area that would reevaluated. It is likely that an School Construction allow 2,000 new housing units. increase will be needed in the number Any school construction in the Additionally, low density rural of patrol cars and the amount of time watershed should adhere to the residential development and town dedicated. This is an opportunity for strictest environmental standards. center development will include new the townships to work together and Surface water quality and quantity housing units within the Hilliard with the Franklin County Sheriff’s should be managed to produce the School District. Office to determine the need and fewest impacts on water quality. the most efficient means of serving School sites, especially high schools, South‐Western City Schools that need. come with additional and unique South‐western City Schools is the challenges to environmentally second largest school district in Washington, Brown, Prairie, Norwich friendly building and site design. It is Franklin County and the sixth largest and Pleasant Townships should recommended that school in Ohio. Southwestern City Schools address the need collectively. While construction adhere to LEED will see an increase in the student Brown Township and Prairie principles for both building and population from the town center Township will service the Town site design. development as well as rural Center, Pleasant Township is home to residential subdivisions that may the largest Metro Park in the State of Neighborhood Schools occur in Pleasant Township. Ohio and with that comes its own Land within the town center should Currently, the district expects to additional service need. This need be provided for the location of exceed capacity in the next six to will likely grow as conservation areas neighborhood schools (for eight years and will need an grow and more destinations are elementary and middle schools) for additional high school, a middle created in the watershed. All of these Hilliard and Southwestern school school and 2 to 3 elementary schools. factors should inform the five districts as the population increases. townships while making decisions Neighborhood schools will be an about emergency services. important component to the success of the town center

B I G D A R B Y A C C O R D C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N / 5-17 5.4 Open Space and Land Metro Parks represents a 5.4.1 Land Conservation Tools Protection Programs formidable and well respected To accomplish the plan principle of organization that provides a valued providing mechanisms to acquire The goal of this plan is to protect all resource to the watershed and the environmentally sensitive areas lands within the Land Conservation community. As part of their (Tiers 1, 2, and 3), a number of Strategy through a suite of Strategic Plan, Metro Parks has existing and new programs will be programs that balance individual identified a goal of preserving an needed. Furthermore, jurisdictions landowner rights with the rights of additional 7,000 acres of land in the of the Accord will need to enter into the larger community for a clean Darby Watershed in cooperation partnerships with established and healthy environment. The best with public and private partners, agencies that have experience and way of preserving land and focusing on land along stream expertise in land management, real permanently protecting sensitive corridors such as the Big and Little estate transactions that can assist areas is to purchase land and Darby Creeks, Hellbranch Run and with targeting available funding remove it from development their major tributaries. The Darby sources from federal, state and local potential; however, purchasing Accord should cultivate a resources. land requires money. relationship with Metro Parks to leverage available resources in the As a newly established partnership, Sources of money at the local pursuit of conservation lands that the Accord is not yet ready to take government level are often limited; meet both the goals of the Accord on land ownership and therefore, relying solely on public and Metro Parks. management of conservation lands. funding for protection of land is However, over time, the Accord often unreliable. Some communities Goals for Conservation could evolve and develop the will support general bonds or agree The conservation of Tiers 1, 2 and 3 ability to own and manage land to increases in taxes to support could yield a conservation network within the planning area and could preservation and conservation of almost 15,000 acres. When possibly have a role as a land efforts. Establishing a recurring combined with land that is already conservancy at the local level or funding stream strengthens a protected in Metro Parks, even watershed level. community’s ability to achieve community parks and easements, conservation goals. Having as well as land within protected Open Space Advisory Council multiple programs and a variety of floodways or Beltwidth, (about It is recommended that the Accord funding mechanisms further 10,000 acres) the conservation establish an Open Space Advisory expands these opportunities. potential reaches 25,000 acres. Council to provide guidance for land acquisition, funding and other To leverage its ability to achieve As an overall goal, the Accord conservation efforts. The Advisory this goal, the Accord will need to should work toward creating a Council should include work with existing agencies, like conservation network of 25,000 representatives from Metro Parks, Metro Parks, to secure funding and acres of public land within the Franklin Soil and Water facilitate the transfer of lands into Franklin County portion of the Big Conservation District, The Nature conservation and to enforce Darby Watershed, including areas Conservancy, ODNR, NRCS, OSU development policies that govern already held in parks and Extension, and the local affected the management of conservation easements. Priorities for jurisdictions. Membership could areas on public and private lands. conservation efforts should be also be extended to interested Organizations like Metro Parks, linked to the Tiers described in the landowners. Members should have Franklin Soil and Water Conservation Strategy in a role in land ownership and/or Conservation District (FSWCD), the Section 3.1. oversight. The Accord and Open Nature Conservancy (TNC), Darby Space Advisory Council should Creek Association, Ohio organize a series of Roundtable Department of Natural Resources Discussions to encourage dialogue (ODNR), Natural Resources among residents about the benefits Conservation Service (NRCS) and of land conservation and how to The Ohio State University (OSU) participate in programs. can provide increased visibility to conservation efforts and help the Accord reach its conservation goals.

5-18 / C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N B I G D A R B Y A C C O R D The Accord and the Open Space Accord should continue to evaluate The following new conservation Advisory Council should play a its ability to take on more programs should be considered: lead role in monitoring the land responsibility including the ability 1. Open Space Fund conservation efforts in the planning to own and manage land. Many communities and agencies are area and promote regional already working with land owners to conservation efforts. It is 5.4.2 Recommended purchase land in the planning area recommended the Accord and its Conservation Programs for use as parks or other public conservation partners meet on a Across the country, communities facilities. The concept behind an open regular basis to review single and are successfully developing tailored space fund includes a recurring joint conservation efforts. The programs aimed at protecting funding stream, similar to a purchase Accord, with the help of the Open environmentally sensitive areas, of development rights (PDR) Space Advisory Council, should culturally important sites and program; however, the goal of the produce a brief, annual summary quality of life values that contribute program is to purchase and acquire report that indicates achievements, to community character and land (not rights). A major identifies cooperative future efforts community health. The Darby consideration in the pursuit of an and monitors overall progress for Accord jurisdictions will need to open space initiative program is the both public and private establish a series of new programs level of resources required to accept conservation efforts and that will allow them to work ownership and maintenance effectiveness at overall protection of toward achieving the conservation responsibilities that come along with the watershed. By providing an of Tiers 1, 2 and 3 and the creation acquiring land. annual summary the Accord can of the Darby Town Center. evaluate its efforts and help build Metro Parks could be a formidable public support for conservation A number of valuable programs partner in the establishment of an efforts. Reporting should recognize already exist through the Natural Accord‐wide open space fund local efforts and landowners for Resources Conservation Service program. Metro Parks and the their contribution to the Accord (NRCS), Franklin Soil and Water Accord could work together to efforts and consider the land that is Conservation District (FSWCD), structure an agreement whereby local being conserved through Ohio Department of Agriculture, jurisdictions would contribute conservation style development. Ohio Department of Natural funding to strategic Metro Park Resources (ODNR) and Ohio acquisition efforts in the planning Through the creation of a Environmental Protection Agency area, based on the Darby Accord Community Authority and other (OEPA). Many existing programs general land use plan. Local creative revenue generating are oriented toward a specific jurisdictions may be able to techniques discussed in Section 5.5, purpose, such as agriculture successfully target state and federal the Accord anticipates generating a easements, conservation easements, grant resources as matching funds in substantial amount of revenue for or incentives for restoring acquisition efforts. Accord land acquisition. Revenue raised for grasslands. The Accord will need a jurisdictions and residents would land conservation should be broader suite of programs to meet need to work together to identify an leveraged with funding from other the goals of the plan. All programs agreeable contribution level for local agencies in the pursuit of identified in the Plan such as funding in establishing an open space conservation goals that meet the easements, purchase and donation initiative and consult with potential objectives of the Darby Accord Plan require willing property owners partners. Local businesses, as well as the objectives of the and funding. Another commonality organizations and other non‐profit agencies with who the Accord among all programs is sufficient groups could also provide monetary partners. The Accord Plan should funding and resources for program support to acquisition efforts and in no way limit or hinder implementation and management. raise awareness for the program. An conservation efforts of other In addition to the programs open space initiative could become a organizations for lands that may be suggested below, policies for major initiative for the Accord and outside the tiers. By partnering development are intended to lead to a brand identity for the Big with key agencies, the Darby create more opportunities for open Darby and more public awareness Accord can provide financial space and are further described campaigns for educational and resources for land acquisition and in Section 4.0. outreach purposes. avoid the burden of land management. Over time, the

B I G D A R B Y A C C O R D C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N / 5-19 Each community within the Accord transfers, this program could accept can be referenced in determining should continue to evaluate their asset contributions other than real requirements for Accord ability to issue general revenue bonds estate, which could be used solely for jurisdictions. Emphasis on parklands that would support conservation the acquisition or preservation of should be geared towards creating efforts. conservation areas or parkland. neighborhood parks, contributing to Establishing a flexible program for the regional Metro Parks system, or 2. Land Stewardship Program. donation could encourage property providing new parks to meet With a dedicated funding stream, it is owners to donate entire parcels, or increased demand for recreational recommended that the Accord portions of their land (i.e. along uses. In all cases, parks should establish a program to purchase Tier stream corridors) for conservation incorporate low impact development 1, 2 and 3 lands from willing property purposes. techniques and innovative materials owners. This program could be called that reduce the amount of impervious Darby Greenspace Initiative, Darby 3. Parkland Dedication Ordinance surface for parking areas. Land Stewardship Program, Darby All residential subdivisions (major Retention/detention ponds and other Open Space Initiative, or some other and minor) of land should contribute stormwater facilities should not count agreed‐upon title. In addition to to the overall parkland and open toward parkland dedication acquiring land by purchase, this space system of the Accord planning requirements program should be used to facilitate a area. New development will result in charitable contribution of land increased demand for recreational Town Center through a gift, testamentary gifts, resources and create opportunities to The Town Center Zone should charitable remainder trusts, land proactively plan for future demand accommodate a number of conservation easements and other and recreational trends. A parkland neighborhood oriented parks that are types of transfers that would benefit dedication ordinance, adopted within close walking proximity to both the landowners and the local among all jurisdictions is residents. The amount of land jurisdiction. This new program recommended to help build a park dedicated should focus on the should be established to acquire, by system that includes different scales amount of people it would be serving purchase and/or charitable donation, of parks such as neighborhood, because of the greater density land in the watershed that will be community and regional parks. development pattern. It is used for open space or parks that is recommended that there be at least 6‐ consistent with Plan priorities. The parkland dedication ordinance 10 acres of parkland per 1,000 people should offer developers a range of provided within the Town Center. The Accord should focus efforts for options in meeting the parkland Neighborhood parks should be purchase on priority conservation dedication requirement including a located within at least ½ mile radius lands in Tier 1. The Accord could dedication of land that becomes of all residential properties. A Master assume ownership and maintenance deeded to the respective jurisdiction, Plan for the Town Center should of land, or the land could remain a transferred dedication of land, or identify appropriate parkland that under private ownership with fee‐in‐lieu‐of one of these options. can provide a range of activities. restrictions placed on it through a Jurisdictions should work with The location of park land should be conservation easement in perpetuity. developers during the early stages of oriented toward protecting Tier 1 Restrictions may include public plan development to determine and 2 elements. access rights if the area is determined which option would best meet the to provide a special linkage or needs of all parties. Parties should be Outside Town Center (including opportunity for future greenway or flexible in negotiating requirements Conservation Development overlay) trail alignment. to meet this obligation. Not all land is The conservation developments suitable parkland. already require that 50% of the land To enhance and implement the be dedicated for open space. Portions objectives of this program, the Accord Parkland dedication requirements of this open space, which are not should make arrangements to have should be linked to development preserved because of important financial/tax professionals available patterns in the Accord area; a single environmental considerations, could for consultation with residents who standard for parkland dedication be appropriate for certain desire to sell or donate their land and encompassing the entire Accord area appropriately designed recreational to assist with the transfer of land for is not practical. Other communities, amenities, playgrounds and public green space and conservation such as Dublin and Columbus spaces. The amount of land provided purposes. In addition to land maintain parkland requirements that for public use for major and minor

5-20 / C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N B I G D A R B Y A C C O R D subdivisions should be between 3 Procedures For residential dwelling units which and 5% of the total gross open space Plat Dedication are not constructed as part of a area and include a set acres per The general arrangement of parkland subdivision, the fee for each dwelling unit amount (Dublin uses and how it serves the neighborhood residential dwelling shall be ½ % of .03 acres per unit plus a minimum of and greater community should be the total land and building costs of 2% of the total gross site). A fee in reviewed and subject to approval of the residential or dwelling unit, with lieu of payment could also satisfy a the local jurisdiction. The local a minimum fee of $300 and maximum dedication requirement. In no case jurisdiction should evaluate the fee of $1000 per unit, regardless of the shall the open space requirement amount of parkland provided, the acreage involved. This fee will be exceed 25% of total gross site area. distribution of parkland, and the evaluated each year by the local quality of the land provided. The jurisdiction and adjusted accordingly Land Dedicated as Parkland local jurisdiction and the developer in order to meet the parkland goals of If a developer chooses to dedicate should meet early in the planning the Accord. land to meet the requirement, the process to discuss options and ideas location of the parkland should for meeting the requirements. Early Dedication Transfers consider the Conservation Strategy of discussions will facilitate approval Dedicated land for parks could be the Plan and should also be linked to during the preliminary plat stage. transferred from one subdivision to any future Master Plan for the Town another if providing parkland on that Center. Any land dedicated for Fee in lieu site is not feasible, there are no parkland will need to be carefully If land dedication is inappropriate or priority environmental protection evaluated to ensure that it can serve insufficient, the local jurisdiction may areas or it is more logical to provide it its intended use. Lands dedicated as request that the subdivider pay a in an adjacent area as a part of a park should not be an after thought park fee‐in‐lieu‐of. The total fee larger green space. These transfers to the development process and should be based on the amount of must be evaluated carefully. should be determined in consultation land dedication required for final plat with the local jurisdiction. Key approval. Each jurisdiction will have 4. Purchase of Development Rights considerations should include: to establish an average value of land (PDR) Program • Preserves and protects Tier 1, 2 or 3 per acre upon recommendation of a A PDR program would allow Conservation areas qualified land appraiser based on landowners to voluntarily sell the • Proximity to other park lands recent land transactions with a development rights of their property, (ensure even distribution) suggested price per acre for raw land or a portion thereof, to the Accord, or • Roadway accessibility (for regional within the jurisdiction. The total fee similar organization. The landowner serving parks) will also be based upon the average would retain ownership and • Opportunities for pedestrian and value of land. The total fee provided maintenance of the land; however, as bicycle connections (off‐road) by the subdivider is determined by: part of the land transaction, the • Vistas and scenic qualities property, or a portion thereof, would • Preserves and protects any Total amount of land dedication X be placed under a conservation woodlands and incorporates them Average value of land per acre easement which would limit any as a park amenity further development. Restrictions • Open to the public (private Fees will be collected and deposited may also stipulate public access recreational facilities should not in a fund managed by the rights if the area is determined to count toward parkland dedication Community Authority. The funds provide a special linkage or requirements) will be used for the acquisition of opportunity for future greenway or recreational facility sites, parkland, trail alignment. Ideally, this program Subdivisions occurring adjacent to and/or the maintenance and will facilitate the conservation of land existing park lands should provide operation of publicly owned for open space and will lead to land linkages to the existing park as part of recreation sites and facilities. Monies being returned to natural, prairie or the open space requirement and any will be issued to the Community open grass lands. All conservation dedicated parkland. Authority at the time of the final plat. easements should be held jointly and No building permits will be issued in perpetuity by an individual unless and until the fee has been property owner or Home Owners provided. Association (HAO) and either the local jurisdiction or the Franklin County Soil and Water Conservation

B I G D A R B Y A C C O R D C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N / 5-21 District. Property owners of a review process for applications; community wants to protect; easements will be required to develop determine which applications it will therefore, they could be classified as a planting plan and management fund; hire personnel to perform an open space program. Fees are plan that will guide the conversion of appraisals and provide assistance to assessed to development proposals land from its current use to carry out the transaction. that wish to increase density and conservation. those fees are used to protect A PDR program within the Darby sensitive lands or resources. To A PDR program could also be used to Creek Watershed that uses public implement the use of a density help farmers retain their land as funds could be leveraged with other transfer fee program, Accord active farmland. It is recommended public agency funding, such as jurisdictions would need to develop that any approvals for PDR for active MetroParks, to realize significant the appropriate zoning language to agriculture lands be subject to the advantages. A recurring funding allow fees to be collected in areas that application of best management source is recommended for a PDR would be subject to increases in practices as part of the agreement. program, similar to that suggested by density, such as the town center area. a more simplified open space fund To provide guidance to the Accord on initiative. Accord jurisdictions would Density transfer charges are triggered how to spend available funding for need to work together to identify an with rezoning requests. They can purchasing rights, the PDR program agreeable contribution level for work with minimum (base) and should be linked to plan priorities establishing a PDR program. maximum (threshold) zoning and have an established application A PDR program could be a stepping densities or can be applied to any process for interested landowners stone to a longer‐term goal of a rezoning that involves an increase in that integrates criteria for protecting TDR program. If the development density or intensity of use. In order to Tier 1, 2 and 3 areas. Preference rights are held and placed into a receive the increase in density, a should be given to properties that “bank” they could be instrumental in developer is charged a transfer fee exhibit environmentally sensitive initiating the first transactions of a per unit of increase. For example, the resources related to protecting TDR program because developers base zoning for a 1 acre parcel (in a water quality. would not have to pursue the DTC zone) is 2 dwelling units per purchase of development rights from acre but the maximum density is 5 A PDR program would require a individual landowners. units per acre (achievable through sufficient funding stream in order to DTC). Assume that each unit of facilitate the out‐right purchase of the 5. Density Transfer Charge density costs $8,000; the developer development rights. The Accord Density Transfer Charges (DTC) are could seek an increase in density up would also need to establish a also designed to guide development to the maximum by paying $24,000. process for severing rights from land; away from sensitive areas that a The money from the transaction would be used to purchase land or easements in the areas that are identified for conservation. With DTCs, conservation efforts are funded by development rather than through public sources and taxes. The Accord should consider developing a density transfer program to capture funds related to requests for increases in density. Although establishing a DTC program does not necessarily require a re‐zoning of the base zoning in all areas, in the case of the town center area a rezoning would be recommended to ensure base levels of development are sufficient to support and warrant public utilities.

Big Darby Creek Source: Metro Parks

5-22 / C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N B I G D A R B Y A C C O R D DTC programs differ from TDRs in the Accord using DTC funds but TDR requires the development of a that they can be used almost those areas could develop as more detailed process for the transfer anywhere. DTC programs do not currently zoned. of the rights, including rezoning require sending and receiving areas sending and receiving areas, or the participation of sellers and Areas approved for up‐zoning establishing administrative processes buyers, although communities can through the use of DTC must be for the transfer of rights and include these elements and other compatible with the overall plan for a extensive outreach to the public about TDR‐like elements, as part of a DTC community. Increasing density on a how the program works. ordinance. DTC programs do not case by case basis will ultimately require any off‐site preservation like increase overall development and It is recommended that the Darby a TDR program. would need to be weighed against Accord continue to support a change factors such as environmental in state legislation that would enable To implement DTC, the Accord impacts and adequate infrastructure the transfer of development rights jurisdictions would need to create an and serviceability. Furthermore, up‐ between any and all jurisdictions ordinance that spells out the purpose zonings across the planning area (incorporated and non‐incorporated). and procedure for the program. The would need to be monitored to The current boundaries of the Town ordinance will need to state the understand the cumulative impact on Center should serve as a receiving amount of the transfer fee and clarify overall growth and development in area and Tiers 1, 2 and 3 would how those funds will be used for the watershed. become sending areas. The informal conservation efforts. Density fees transfer of rights could occur today must consider the valuable increment Within the Darby Watershed, DTC within a single jurisdiction among of the additional development unit. may be most appropriate on a limited agreeable parties. Informal transfers Fees should be reasonable and set at case by case basis. However, because should be encouraged as a way to an amount that still provides a public sewer and water will not be conserve land in the Tiers and help reasonable return on investment for made available in all areas, increases create the Town Center. A successful the developer; otherwise the program in density will most likely not be TDR program requires an active will not be used. Developer fees are suitable for remote areas of the housing market and a supportive calculated and typically collected planning area. Any DTC program for public that participates in the when building permits are issued. the Accord area should be applied to program. TDRs offer landowners each jurisdiction and coordinated another option for realizing the value A disadvantage of using a DTC is among all ten jurisdictions. By of their land. that it potentially postpones many of pooling funds collected through the the decisions that are made at the program, the Accord jurisdictions 7. Land Owners Roundtable Series start of some classic TDR programs could better leverage their funds and This planning process has revealed a (Pruetz, 2003). In some TDR target specific areas for preservation need to hold a series of roundtable programs, receiving areas are not or conservation. discussions to inform landowners only designated, but rezoned so that about the priority conservation areas developers are administratively 6. Transfer of Development Rights and to explain conservation options approved to exceed the TDR (TDR) Program such as easements, donations, threshold as long as they comply As a long term goal, the Accord purchase of development rights and with the code and buy the necessary should consider the development of a other programs. The majority of land TDRs. In DTC, developers propose TDR program as part of the tool box in the watershed is within private zoning changes on a parcel by parcel of options to achieving the land holdings. A pro‐active approach basis, with each proposal evaluated conservation of Tiers 1, 2 and 3. A with land owners could result in an separately (Pruetz, 2003). This TDR program would allow willing increased willingness to contribute provides less certainty to developers. property owners in Tiers 1, 2 or 3 land into an open space network and In many TDR programs, sending (sending areas) to negotiate and sell land conservation strategy. The areas are clearly identified and in their development rights to buyers Accord should consider establishing some cases down‐zoned to reflect that then execute them in appropriate a core group of landowners, community preservation goals and ‘receiving areas’ (town center). The representative of all Accord promote conservation and the use of value of a development right is jurisdictions, for this effort. This TDRs. This is not an approach found determined through negotiation group can serve as ambassadors to in DTC programs; areas identified for between the buyer and seller and is a other landowners and interested conservation would be pursued by function of the real estate market. citizens, distribute information and

B I G D A R B Y A C C O R D C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N / 5-23 provide a voice for landowners. Key Another example of a backyard partners in this effort should include conservation program can be found Accord jurisdictions, FSWCD, ODNR, in the Northern Virginia Planning Metro Parks and key local District Commission’s “Maintaining institutions. Your BMP” handbook. The book is designed for property owners and 8. Backyard Conservation Program. suggests basic maintenance and Similar to the program established by planting tasks for BMPs. the Friends of Olentangy Watershed 9. Nutrient Reduction Programs for Farmland. Nutrient reduction programs for farmers are one way to encourage better site management in active agriculture areas. A program in the Stillwater watershed in Ohio led by Ohio State University Department of Agricultural, Environmental, and Development Economics is running such a program. The Ohio State The Friends of Olentangyy Watershed University Group performance provides signs to those members contracts tie payments farmers practicing backyard conservation. http://www.olentangywatershed.org/ receive for reducing pollution loads to measurable pollution reductions downstream, using small sub‐ (FLOW), a backyard conservation watersheds of 1000 – 2000 acres and program provides guidance to groups of 5 – 15 farmers. (Sohngen, homeowners in how to maintain their March 2005). Farmers must purchase property in harmony with the the equipment and payment for watershed. The program could be nutrient reductions is measured part of an overall Healthy Streams collectively downstream marketing campaign designed to (Taylor, Sohngen, Randall and engender support for conservation Pushkarskaya, 2004). projects and raise awareness of the role that each resident has in protecting the Darby watershed. Program components could include lawn care, pest management, suggest native tree and vegetative plantings, include instructions on how to develop and maintain a rain garden or other lot‐level best management practices. This program could be expanded to school‐aged children.

Franklin SWCD assisted in the development of the FLOW program and is working to develop a central Ohio‐wide Backyard Conservation program for dissemination to all residents. Franklin SWCD is a potential partner for the Accord in developing a Healthy Streams program.

5-24 / C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N B I G D A R B Y A C C O R D 5.5 Revenue It is also worth noting that these school districts would be held three revenue sources should not be harmless. The result is that the tax The following section addresses a viewed as the only revenues increment financing revenue stream key element in the implementation available to fund the plan. Other that is the basis for these projections strategy for the Big Darby Accord: sources that should be considered is limited to the “non‐school” share the funding opportunities. These and pursued for Plan of each real property tax dollar funding opportunities are based on implementation include state and generated by any new development potential revenue that could be federal grants and water and sewer permitted in the planning area. The realized for the planning area revenues. TIF revenues shown below include through the implementation of a any non‐school amounts that are new community authority, tax The revenue assessments also subject to potential sharing increment financing and/or completed as part of this effort with overlapping townships and developer contributions. For the should be regarded as preliminary county agencies. purposes of this plan, there has in nature and indicative only of the been an analysis and initial set of order of magnitude of the financing With respect to a new community projections prepared for all three capacity for each tool, but by no authority charge, projections are sources of revenue. This analysis means definitive. This is due to the based on a ten mill charge that includes a number of assumptions, fact that these projections are based would be imposed on each new noted in the following discussion, on development assumptions that residential unit or structure for 30 and several assumptions regarding are subject to change. years. the level of fees and assessments that would be applied. Although As possible sources for funding Over the 30 year period, it is provided as part of this plan, these aspects of the plan, revenue streams assumed that the allocation for the matters will require further and related capital evaluations of first 20 years would be one half (5 discussion among the various financing capacity were prepared mills) to local public infrastructure jurisdictions and stakeholders that for the following three sources: improvements and community would be impacted by these costs 1. A new community authority facilities, and one half (the other 5 to determine the appropriate fees (NCA) mills) to regional improvements, and assessments. These 2. Tax increment financing (TIF) with the full ten mills allocated jurisdictions and stakeholders 3. Development fee contributions. entirely to regional improvements would also be participants in the for years 21 through 30. implementation of these revenue These three revenue sources were sources. evaluated because of their proven It was also assumed in the case of central Ohio track records in both tax increment financings and An important factor in considering funding public infrastructure in the new community authority that the level of revenue sources that connection with new residential each would apply to both could be generated is determining and commercial development in residential and commercial how these funds could be used. Hilliard, Powell, Dublin, New development. This Plan identifies a number of Albany and the City of Columbus’ priorities that should be pursued as recently adoption of all three of For both tax increment financing implementation efforts coalesce: these revenue sources as part of its and new community authority • Infrastructure (utilities and roads) “Pay As You Grow” policy. charges ‐‐ which are applied to the • Regional stormwater management assessed value of each new (acquisition, construction, 5.5.1 Key Assumptions structure or unit ‐‐ a growth factor maintenance) A number of key assumptions have of 3% of that value with every • Open Space and Land Conservation been used for the basis for revenue triennial update or sexennial (in partnership with other agencies) projections. reappraisal was assumed. It was • Water Quality Monitoring assumed that the true value of each • Community Facilities In connection with any tax increment unit as determined by the county • Stream Restoration financing, it is assumed that the tax auditor would be approximately • Supporting resources to implement increment financing would be for 90% of the sale or per square foot and update the Accord Plan (plan the maximum legally permitted 30 value, with that true value then review, coordination) years in duration on each improved reduced to tax value of 35% of parcel, but that the overlapping true value.

B I G D A R B Y A C C O R D C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N / 5-25 With respect to any development fee management practices, regional projected revenues are expressed in contribution, a $2,500 per unit fee stream restoration efforts, sewer terms of both the actual amount to was assumed that would be paid at extension to the Town Center area, be collected over a described period the time a building permit is drawn and/or community‐based of years, as well as the “PV” or for each residential unit. If a wastewater treatment systems in “present value” of that long term development fee is already the rural conservation areas. stream of revenues. Present Value imposed by a local jurisdiction, that is the value of that future cash flow jurisdiction could receive the 5.5.2 Projections discounted (in this case at the rate balance of the proposed $2500 per The above assumptions were of 5%) into its value in today’s unit fee to be applied to items applied to build‐out assumptions in dollars. Present Value is also a very consistent with the Plan. In connection with each of the rough measure of the financing addition, jurisdictions could identified development areas of the capacity of that long term revenue discount developer contributions Town Center, Hilliard growth area stream. by allowing credit for extraordinary and the areas identified for rural costs incurred by a development conservation development. Town Center Residential associated with regional best In the figures that follow, the Residential development in the town center assumes a build‐out of NCA Charge 400 residential units built per year TIF Fees Local Share Regional Share commencing in 2009 with an Amount (millions) $213.6 $12.5 $36.6 $79.1 average sales price of $200,000. PV (million) $71.3 $7.8 $14.0 $21.4 Based on a minimum build‐out Per Unit $1,500.00/yr $2,500.00 $630.00/yr scenario of 5,000 total units with Length per Parcel 30 years One time 30 years build‐out complete in 2021, the Figure 5.7 Town Center - Minimum Build-out Scenario approximate revenues and Approximate Revenues – 5,000 Total Units (Build-out Complete 2021) financing capacity for a non‐school TIF, a $2,500 developer contribution NCA Charge fee and a ten mill new community TIF Fees Local Share Regional Share authority charge in this area are Amount (millions) $89.4 $5.0 $14.3 $30.9 identified in Figure 5.7. PV (millions) $32.2 $3.5 $6.1 $9.3 Per Unit $1,500.00/yr $2,500.00 $630.00/yr Town Center Commercial Length per Parcel 30 years One time 30 years For Town Center commercial, the Figure 5.8 Hilliard Growth Area revenue and financing projections Approximate Revenues – 2,000 Total Units (Build-out Complete 2017) assume a build‐out of 850,000 square feet (SF) of office space NCA Charge costing $100 per square foot over TIF Fees Local Share Regional Share ten years. Projections also assume a Amount (millions) $534.1 $12.5 $99.4 $214.5 build‐out of 900,000 SF of large PV (millions) $178.2 $7.0 $34.1 $52.0 commercial space at $75 per square Per Unit $3,920.00/yr $2,500.00 $1,575.00/yr foot of construction cost over ten Length per Parcel 30 years One time 30 years years and another 500,000 SF of Figure 5.9 Low Density Development (Conservation Development Areas) small commercial space at Minimum Build-out Scenario Approximate Revenues – 5,000 Total Units construction cost of $75 per SF over (Build-out Complete 2023) the same ten year period. Finally, it assumes that build‐out begins in 2009. NCA Charge TIF Fees Local Share Regional Share Based on these assumptions, a non‐ Amount (millions) $837.1 $30.0 $150.3 $324.5 school TIF would generate PV (millions) $281.7 $18.3 $54.2 $82.7 approximately $51.4 million of Length per Parcel 30 years One time 30 years revenue over 30 years, yielding a Figure 5.10 Aggregate Projections - Minimum Build-out Scenario financing capacity at a 5% Approximate Revenues– 12,000 Total Units borrowing rate of approximately $17.5 million.

5-26 / C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N B I G D A R B Y A C C O R D Hilliard Residential 5.5.4 Uses of Revenues The charge may also be applied to For the Hilliard growth area, the Based on their legally permitted operation and maintenance costs of following projections are based on uses, the nature (one time or those facilities, and thus is more 200 residential units per year, sustaining over time) of each, the flexible than TIF revenues. It may commencing in 2008, for a total of source of payment and other also be possible to fashion a 2,000 units, with an average sales considerations, likely priority “prepayment credit” against this price of $200,000. “uses” for the three revenue revenue stream for developer streams evaluated might be as conservation expenditures in support Low‐Density follows: of the Big Darby Plan. For low‐density residential development outside of the higher 1. Tax Increment Financing Revenues 3. Developer Contributions growth areas, assumptions include These revenues are generally limited Developer contributions might most 200 built residential units each of to capital financing of “public logically be segregated into a fund for the first five years and 400 units infrastructure improvements” and the acquisition of land and built in each year thereafter, therefore would be used to pay or development rights to implement the commencing in 2009. All units are finance capital costs of the following Big Darby Accord and Plan. It may assumed to have an average sales in connection with the Plan: also be possible to establish credits price of $500,000. Given the long ƒ Public roads and highways; against these contributions based on term nature of this build‐out, the ƒ Water and sewerlines; the value of development rights or build‐out assumption is based on ƒ Stormwater and flood remediation land acquisition and donation that is 5,000 total units as reflected in projects, including stream made by a developer. Figure 5.9. remediation; and ƒ Land acquisition. In addition to the revenue sources Aggregate Revenue Projections named above, other possible The aggregated revenue projections Although regional improvements traditional public finance revenue from all three revenue sources for called for by the Big Darby Accord sources for various public the Town Center, Hilliard and low‐ may be the first priority for these infrastructure improvements exist. density development assumptions resources, they may also be allocated These include, for example, the use set forth above, are presented to public infrastructure of utility revenues in support of Figure 5.10. improvements in each jurisdiction. sewer and waterline extensions into The jurisdictions may also determine developing areas. In light of the 5.5.3 Summary Revenue that a portion of the TIF revenues extensive infrastructure and Big Considerations (with Respect to should also be allocated to the public Darby Plan conservation needs Build‐out Assumptions and agencies that normally benefit from identified for the area, all revenue Revenue Projections) real property taxes. sources will likely be needed to All of these revenue tools are fund development and the plan. assumed to reflect an agreed upon 2. New Community Authority consensus among the members of Community Development Charge Any tax increment financings the Accord and the development This charge may be applied to pay which would need to be authorized community that would be active in costs of: by the relevant overlapping the Accord area, as was the case ƒ Land acquisition as part of the Big township or county or municipal with Columbus Pay As You Grow. Darby Accord development jurisdictions, while any community This consensus is important program; authority would need to be because these tools are only ƒ Land development including water approved by the City of Columbus revenue‐producing to the extent distribution systems, sewers, and the Franklin County they are agreeable to the sewage collection systems, roads, Commissioners. development community. If the streets, curbs, gutters, sidewalks, combination of tools is overly storm drainage facilities and other burdensome to development in installations or work, whether these areas, development will not within or without the new occur resulting in reduced community district area; and revenues. ƒ Community facilities.

B I G D A R B Y A C C O R D C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N / 5-27 5.6 Early Actions Update Development Review Timeframe: 6‐12 months Processes Accord jurisdictions should work The participating jurisdictions Perform Facilities Planning for together to establish the necessary should update their development Services processes and programs that are review processes to integrate the Accord jurisdictions should vital for plan implementation. The Big Darby Accord Advisory Panel, perform facilities planning for the following early action items as described in Section 5.1. provision of water and central and identify priority steps for plan non‐centralized wastewater implementation. The emerging Update Submission Requirements services according to the Accord Memorandum of Understanding Each jurisdiction should review and Plan. Accord jurisdictions should (MOU) provides further refinement make changes to their development continue to work together with of these actions. application submission technical experts to address issues requirements to reflect the priorities concerning the treatment of waste Timeframe: 1‐4 months of the Big Darby Accord Plan. This water for areas that will not be process should include the serviced by central sewer and Facilitate Accord Plan Adoption agreement to use a development water. This will include identifying Each jurisdiction should submit the review checklist. appropriate technologies, Accord Plan to elected officials and management, regulation and approving bodies for review and Update Utility and Service Permits enforcement. Strong consideration approval. Each jurisdiction should The jurisdictions should examine should be given to establishing an follow their established public and modify, if necessary, their inspection and enforcement review processes for plan adoption. utility and service permit process program for HSTS to ensure proper in order to adhere to function. Appendix F offers draft Complete a Memorandum of recommendations outlined in the recommendations put forth by the Understanding Big Darby Accord Plan. Darby Alternative Wastewater The participating jurisdictions Treatment Technical Advisory should agree to a memorandum of Timeframe: 6‐9 months Committee related to options for understanding which outlines the alternative wastewater treatment relationship and obligations of the Identify Staff Resources to Carry systems. jurisdictions within the Darby Out Plan Implementation Accord Plan framework. To ensure that plan implementation Initiate a Town Center is occurring, and that efforts are Master Plan Timeframe: 2‐6 months moving forward, it is A Master Plan for the proposed recommended that the Accord Town Center should be developed Update Local Regulations jurisdictions appoint at least one to adhere to recommendations Each jurisdiction should update staff person to coordinate made in the Big Darby Accord Plan. land use policies and documents implementation efforts, including including comprehensive plans, the Big Darby Accord Advisory Timeframe: 6‐18 months zoning and subdivision regulations Panel. Accord jurisdictions should Establish a New Community to ensure consistency with the jointly fund this position. This Authority (NCA) and Non‐school Accord Plan. Jurisdictions should person should be charged with Tax Increment Financing (TIF) work together on this task. coordinating activities in the Revenue Mechanisms immediate months after plan The participating jurisdictions Timeframe: 4‐6 months completion, pursuing funding and should create a new community creating partnerships. Outreach authority and adopt appropriate Establish the Big Darby Accord and advocacy to other communities legislation for the creation of such Advisory Panel in the watershed should also be an entity. The creation of the This panel should include members pursued and could be coordinated Authority will require the of the Accord. This panel should by staff. establishment of by‐laws among provide non‐binding review of other procedural requirements development‐related proposals for including funding priorities. consistency with the overall Participating jurisdictions should Mission Statement of the Accord also establish a non‐school TIF. and the Big Darby Accord Plan.

5-28 / C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N B I G D A R B Y A C C O R D Designate an Environmental Monitoring Group and Open Space Advisory Council. The Darby Accord jurisdictions should establish an Environmental Monitoring Group to lead and facilitate development of a water quality monitoring program (and procedures) and an Open Space Advisory Council to coordinate land conservation efforts.

Timeframe: Ongoing

Education and Outreach The Big Darby Accord Advisory Panel and supporting partners should continue education and outreach to inform property owners, developers and elected officials of the goals and objectives of the Accord Plan, as well as the means being employed to implement the Plan. Efforts should be made to reach out to other watershed communities to encourage regional collaboration and adoption of Accord standards.

B I G D A R B Y A C C O R D C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N / 5-29

5-30 / C H A P T E R 5 . 0 ― I M P L E M E N T A T I O N B I G D A R B Y A C C O R D Big Darby Accord Watershed Master Plan Appendix

Prepared for City of Columbus Pleasant Township City of Hilliard Prairie Township Grove City Washington Township Brown Township Village of Harrisburg Norwich Township Franklin County

FINAL / JUNE 2006 Prepared by EDAW Inc

In Collaboration With: MSI Design EMH&T Ohio State University Extension Squire, Sanders & Dempsey LLP Schottenstein Zox & Dunn Trans Associates Appendix A • Final Modeling Study • Final Pilot Study Model Appendix B • Funding Sources Appendix C • Reference Information • Inventory of GIS Data Appendix D • Development Review Checklist Appendix E • Stormwater Utility Appendix F • Alternative Wastewater Treatment THIS PAGE LEFT INTENTIONALLY BLANK Big Darby Accord Water Quality Modeling Summary Report

EMH&T, Inc. June 2006

Table of Contents

A. Purpose...... 1 B. Pollutant Loading Considerations...... 1 C. Initial Model Set-Up ...... 1 1. Digital Elevation Model (DEM) ...... 1 2. Spatial Extent ...... 1 3. Delineation of Sub-basins, Hydrologic Response Units (HRUs)...... 2 4. Revision of Sub-basin Areas...... 3 5. Revision of Main Channel Widths/Depths, Channel Lengths ...... 3 6. Study Period...... 4 D. Data Inputs...... 4 1. Weather/Climate Data...... 4 2. Soil Data...... 6 3. Land Use Data...... 6 a) Baseline Conditions ...... 6 b) Final Land Use Scenario ...... 7 4. Initial Groundwater Pollutant Concentrations...... 9 5. Agricultural Data...... 8 6. Fertilizer Application Data...... 8 a) Crops ...... 9 b) Livestock Manure Application...... 10 c) Lawns ...... 12 d) Recreational Fields/Parks...... 12 e) Golf Courses...... 12 7. Urban Land Use Parameters...... 13 a) Build-up/Wash-off Parameters...... 13 b) Runoff Curve Numbers and Percent Impervious Values ...... 13 E. Calibration/Baseline Model ...... 14 F. Final Land Use Scenario Model...... 18 G. Conclusions...... 20

BIG DARBY ACCORD APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. / A THIS PAGE LEFT INTENTIONALLY BLANK A. Purpose

The purpose of the water quality modeling was to determine the impact on water quality, measured in terms of pollutant loading, related to projected land use changes within the Big Darby Accord planning area. Using the Soil and Water Assessment Tool (SWAT) software, a baseline condition model was created similar to the Generalized Watershed Loading Functions (GWLF) model established by the Ohio EPA for the Big Darby Creek TMDL analysis and draft report. The SWAT baseline model was calibrated for flow to the USGS gage along Hellbranch Run; the model was then calibrated to the EPA’s GWLF model results for Total Nitrogen (TN), Total Phosphorous (TP), and Total Suspended Solids (TSS). Although the Ohio EPA did not publish calculated TN loadings in the TMDL report, we were provided detailed and summary model results by the Ohio EPA that included those values for the Hellbranch Run watershed and the 14-digit HUC’s that are at least partially within the Big Darby Accord planning area.

The final calibration model’s parameters were then used to analyze the effects of the final land use plan, comparing the resultant pollutant loadings predicted by the SWAT model to the target water quality goals published in the OEPA draft TMDL report. The model results were also used to evaluate the requirements for stormwater best management practices (BMPs), in an effort to mitigate the impact of development on pollutant loadings.

B. Pollutant Loading Considerations

The pollutant constituents chosen for this analysis, Total Nitrogen (TN), Total Phosphorous (TP), and Total Suspended Solids (TSS), are those that are commonly considered and are most likely to be affected by changing land use conditions. Heavy metals, especially within the Big Darby Accord planning area, did not appear to be a significant consideration in the Big Darby Creek TMDL. Furthermore, there are no anticipated future industrial land uses within the Big Darby Accord area that would be a significant contributor of those pollutants.

C. Initial Model Set-Up

1. Digital Elevation Model (DEM)

The first step in the modeling process was to create a Digital Elevation Model (DEM). Using the Arc/INFO “TOPOGRID” command, a 15-ft DEM was created from the following data inputs: x Franklin County Auditor’s spot elevation data x Franklin County Auditor’s 2-ft contours x Madison County Auditor’s 5-ft contours x 1:24,000 scale USGS Digital Line Graph (DLG) contours (for Pickaway County) x Blue line streams from Franklin County Soil and Water Conservation District’s (FSWCD) hydrography layer x Blue line streams from USGS Digital Line Graph (DLG) hydrography, manually edited to include only stream centerlines and to better correspond to contour data (for areas outside of Franklin County)

2. Spatial Extent

The Big Darby Accord planning area consists of the portion of the Big Darby Creek watershed located within Franklin County. To restrict the automated sub-basin delineation to Franklin

BIG DARBY ACCORD APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. / 1 County, a mask was used. However, instead of simply using a mask equivalent to the Franklin County boundary, small portions of Madison County and Pickaway County were also required for SWAT to correctly delineate the portion of Big Darby Creek that forms the Madison County/Franklin County boundary and the stream network at the southern part of the Big Darby Accord planning area.

Therefore the mask used during the sub-basin delineation only limited the extent of the sub-basins along the eastern, western, and northern sides. Along the eastern and western sides, the mask extent was for the most part identical to the initial boundary of the Big Darby Accord planning area, which consisted of the Madison County/Franklin County boundary on the west and the HUC 14 Big Darby Creek watershed boundary on the east. (Note: the Accord planning area’s eastern boundary was later revised; this is discussed below in the section “Revision of Sub-basin Areas”.) However, for Big Darby Creek to be correctly delineated along the Madison County/Franklin County boundary, the mask actually extended 100 feet west of the Big Darby Creek centerline into Madison County. Along the northern side, the mask extent was equivalent to the Franklin County boundary and the Hellbranch Watershed Forum (HWF) boundary for the Hellbranch sub-watershed.

3. Delineation of Sub-basins, Hydrologic Response Units (HRUs)

Sub-basin outlets were selected according to the following criteria:

x Within the Hellbranch Run sub-watershed, sub-basin outlets corresponded to those utilized by the Hellbranch Watershed Forum (HWF) to maintain general agreement with the HWF for potential comparison of model results. The SWAT sub-basin boundaries delineated using the DEM were in general agreement with the HWF sub- basin boundaries.

x For areas outside of the Hellbranch Run sub-watershed, a sub-basin outlet was placed at each blue line stream’s confluence with Big Darby Creek. Additional sub-basin outlets along Big Darby Creek were selected such that an average sub-basin size of approximately 1,000 acres was maintained.

x Sub-basin outlets were created at the outlets of each of the 14-digit HUC’s contained or at least partially contained within the study area, to allow for potential pollutant calibration with EPA data. However, with the exception of the Hellbranch sub- watershed outlet, these outlets were not used as calibration points since the majority of the area within each 14-digit HUC was actually located outside of the modeling study area and would therefore not provide for an accurate calibration.

x A watershed inlet was created at the confluence of Little Darby Creek with Big Darby Creek, which corresponds to a 14-digit HUC outlet, to better allow for OEPA/GWLF point source pollutant loadings for areas outside of Franklin County to be added to the model. After the establishment and calibration of the baseline SWAT model, however, a decision was made not to include point source loadings for areas outside of Franklin County since these values were unable to be accurately projected for the time period corresponding to the final land use scenario. The resultant exclusion of the Little Darby Creek tributary area from the SWAT model was determined to have little to no impact on the model results, since the majority of the land in this region is currently

2 / APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. BIG DARBY ACCORD MetroPark forested land and continues to be designated as forested land in the future land use scenario.

The result of the SWAT sub-basin delineation process was a 53,068-acre watershed comprised of 51 sub-basins (average of 1,041 acres per sub-basin). The SWAT sub-basins along with the Big Darby Accord planning area can be seen in Figure 1. The modeling study area is essentially comprised of two large sub-watersheds: the Hellbranch Run sub-watershed (25,154 acres) and all other areas within Franklin County that are directly tributary to Big Darby Creek. It should be noted that a small area in the southwest corner and the very northernmost tip of the Big Darby Accord planning area are actually located outside of the Big Darby watershed boundary, so these regions were not included in the modeling efforts. The 51 sub-basins initially created for the SWAT calibration model were also utilized for the final land use scenario model so results from the two models could be readily compared.

To adequately capture the diversity of land uses and soils present within each sub-basin, the SWAT model then divides each sub-basin into even smaller units, referring to unique combinations of land use and soil type as Hydrologic Response Units (HRUs). HRUs allow for increased accuracy in the model since loadings from each HRU are calculated independently, based on specific parameters that correspond to land use/management operations and soil type (i.e., percent impervious, plant species, fertilizer application rates, soil hydrologic group, etc.). Although the sub-basin boundaries were consistent for the baseline/calibration model and the final land use scenario model, since the land use coverages for the two models varied significantly, the total number of Hydrologic Response Units (HRUs) analyzed in each model differed. On average each SWAT model contained at least 10 HRUs per sub-basin; a further discussion of the HRU delineation process for each model is included in the “Land Use Data” section below.

4. Revision of Sub-basin Areas

For some sub-basins along the eastern boundary of the study area, the sub-basin areas were manually revised in SWAT to include additional drainage area. This revision was due to a change in the eastern boundary of the Big Darby Accord planning area that occurred after the sub-basin delineation process had already been completed and work on the calibration model was underway. The revised boundary corresponds to either the Hellbranch Watershed Forum boundary or the HUC 14 Big Darby Creek watershed boundary, whichever is “greatest”. Where the boundary was changed, a larger total drainage area is reflected in the SWAT model. For the majority of the sub-basins with revised areas, the additional drainage area was simply distributed proportionally amongst the various HRUs already established. However, where significant differences were observed in terms of land use percentages within a sub-basin, HRUs were added, revised or deleted as necessary to maintain accuracy in the model.

5. Revision of Main Channel Widths/Depths, Channel Lengths

The default SWAT values for main channel widths and depths were overwritten; instead, the main channel widths and depths were calculated using the following regional curve equations provided by The Ohio State University (OSU): Width (meters) = 0.477 x (Drainage area in ha)0.4032 Depth (meters) = 0.0474 x (Drainage area in ha)0.3167

BIG DARBY ACCORD APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. / 3 Based on a GIS analysis of the river shapefile delineated by SWAT, some main and tributary channel lengths were also manually revised, since the SWAT program had incorrectly clipped or merged some river segments.

6. Study Period

The designated modeling study period was selected to match that used by the OEPA in its TMDL analysis: April 1, 1994 through March 31, 2004.

D. Data Inputs

A summary of the data inputs used in the SWAT water quality modeling process is shown as Table 1. This data (with the exception of the baseline land use data) was used for both the baseline/calibration model and the future land use scenario model.

1. Weather/Climate Data

Precipitation and temperature data for April 1994 through March 2004 were provided by the OEPA from its Big Darby Creek TMDL efforts. This data was collected from eight gages, none of which were located within the Big Darby Accord planning area. Of these, the Columbus, London, Marysville, and Delaware gages were in closest proximity to the planning area; however, when comparing the relative magnitude and timing of precipitation events to the observed flows at the U.S. Geological Survey’s (USGS) Hellbranch Run gage, none of the gages had data that was consistent with the Hellbranch sub-watershed over the entire span of the study period.

Various combinations of gages and individual gages were then tested in the model: the average of the nearest four gages, the average of all eight gages, and individual data from the Columbus and London gages. However, all yielded poor calibration results. As a result, additional precipitation data sources were explored. Data from the three nearest City of Columbus gages were incomplete and inaccurate for large portions of the ten-year study period. Finally, after evaluating precipitation data from a variety of sources, the National Weather Service (NWS) gage at the Port Columbus International Airport was determined to most accurately represent the conditions within the Hellbranch Run sub-watershed. The precipitation events recorded at the NWS gage best corresponded to the flow data from the USGS Hellbranch Run gage in terms of both relative magnitude and the timing of events.

For consistency, temperature data from the same NWS gage was then also selected for use in the SWAT model. However, NWS precipitation and temperature data were only available for the duration July 1996 through March 2004, which does not include the beginning of the designated ten-year study period (April 1994 through March 2004). Therefore, for the time period ranging from April 1994 through June 1996, precipitation data from the Ohio Agricultural Research and Development Center (OARDC) Columbus Station gage and temperature data from the OARDC Delaware Station gage were utilized. This substitution did not have a significant effect on the accuracy of the SWAT model or the interpretation of its results, since these gages are located in close proximity to the study area and are also considered to be adequately representative of the weather/climate in this region. Also, since the SWAT model requires one to two years for initial conditions to equilibrate, the calibration period was set as study years three through 10 (April 1996 through March 2004), during which the majority of the precipitation and temperature data consisted of the NWS gage data.

4 / APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. BIG DARBY ACCORD All other weather/climate data (solar radiation, wind speed, relative humidity, and potential evapotranspiration) were simulated by SWAT, which uses a database of national weather information to create approximations customized to a specific geographical area.

Table 1 SWAT Data Input Summary

Applies to Data Input SWAT Land Data Source(s) Use(s) OARDC Columbus Station gage (Apr 1994-Jun 1996); Precipitation data All land uses NWS Port Columbus Airport gage (Jul 1996-Mar 2004) OARDC Delaware Station gage (Apr 1994-Jun 1996); NWS Temperature data All land uses Port Columbus Airport gage (Jul 1996-Mar 2004) All other Approximated within SWAT using national weather/climate All land uses weather/climate data database Soil data All land uses NRCS Soil Survey Geographic Database (SSURGO)

Baseline land use NA OEPA Hybrid Land Use Coverage data Initial groundwater concentrations of All land uses OEPA nitrate and soluble phosphorus Agricultural operations including Agricultural crop types/rotations, NRCS, research conducted by OSU, OSU Extension Land - Row tillage practices, Bulletin E-2567 (http://ohioline.osu.edu/e2567) Crops (AGRR) fertilizer application rates Manure application Pasture (PAST) OEPA from livestock Pervious Lawn fertilizer OSU Extension FactSheet HYG-4006 portions of all application (http://ohioline.osu.edu/hyg-fact/4000/4006.html) urban land uses OSU Extension FactSheet SRT-2-05 Recreational field (http://ohioline.osu.edu/srt-fact/0002.html), Purdue Parks (PARK) fertilizer application University's Turfgrass Science report AY-325-W (http://www.agry.purdue.edu/turf/pubs/AY-325-W.pdf) Virginia Cooperative Extension Publication Number 430- 399 (http://www.ext.vt.edu/pubs/turf/430-399/430- Golf course fertilizer Golf Courses 399.html), Delaware Department of Natural Resources and application (GOLF) Environmental Control "Turf Nutrient Management" report (http://www.dnrec.state.de.us/water2000/Sections/Watershe d/WS/fact_appo_turf_nutrient.pdf) Impervious Build-up/wash-off portions of all SWAT, OEPA parameters urban land uses Runoff curve All urban land numbers and percent SWAT, NRCS TR-55 documentation uses impervious values

BIG DARBY ACCORD APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. / 5 2. Soil Data

NRCS SSURGO data was utilized due to its more detailed determination of the soil types. Additionally, this soil data was utilized by the OEPA for the TMDL. To minimize the number of HRUs created while still maintaining the distinct data attributes used by SWAT, the SSURGO soil types were reclassified into soil series. Figure 2 displays the predominant soil series within the modeling study area (those soil series comprising at least 1% of the overall watershed area).

3. Land Use Data

a) Baseline Conditions

The land use coverage used to represent baseline conditions in the calibration model was provided by the OEPA and is identical to that used in the OEPA’s TMDL analysis. This hybrid land use dataset includes data from the USGS National Land Cover Dataset (NLCD - 1992), OEPA’s analysis of forested land cover using 1997 Landsat 5 satellite imagery, an OEPA-funded land use study based on 2000-2001 Landsat 7 satellite imagery conducted by the University of Cincinnati, and land use data based on 1997 Landsat Thematic Mapper data provided by Dr. Steve Gordon at The Ohio State University (OSU). To verify that this hybrid land use information reflected the most current land use within the Accord planning area, a parcel-based MORPC land use coverage representing 2003 conditions was revised using 2005 Franklin County Auditor's land use codes, taking into account any changes from agricultural land or open space to other land uses. This revised MORPC dataset (showing urban land uses/zoning type categories only) was then merged with the natural land cover data from the hybrid land use coverage to create an updated 2005 existing land use layer.

After comparing the updated 2005 existing land use dataset to the original OEPA hybrid land use dataset, it was determined that the differences between the two land use coverages would likely have very little impact on the SWAT modeling results. Therefore, for consistency with the OEPA TMDL analysis, the hybrid land use dataset was selected to represent baseline conditions in the baseline/calibration model.

Based on the land use descriptions for each category, a “look-up” table (Table 2) was created to convert the hybrid land use categories to the appropriate SWAT land use categories. Since a significant part of the hybrid land use dataset was from the USGS 1992 National Land Cover Dataset (NLCD), the majority of this lookup table was derived from a lookup table that had previously been created to convert NLCD classes to SWAT land use classes, based on research and trial runs in SWAT. A map showing the hybrid land use coverage (converted to SWAT land use categories/codes is included as Figure 3.

The SWAT land use data was then used in conjunction with SSURGO soil data from the NRCS to create HRUs. A 10% threshold value for land use and a 10% threshold value for soil type were utilized to limit the total number of HRUs created, so that in subsequent modeling steps the HRUs could be effectively managed. This meant that if a particular land use or soil type was not did not comprise at least 10% of a sub-basin, an HRU was not created. Many of the land uses in the hybrid land use coverage represented only a very small portion of the entire modeling area (less than 1% in most cases) and less than 10% of each sub-basin; thus, only the following SWAT land use categories remained in the calibration model after the HRU delineation: AGRR, FRSD, PAST, URLD, and URMD.

6 / APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. BIG DARBY ACCORD After the initial creation of 464 HRUs, some additional HRUs were then manually added to the model to assure the accurate representation of parks and golf courses in the study area and to account for the land uses outside of the sub-basin boundaries but yet still inside the Accord planning area (due to the revision in the eastern boundary of the Accord planning area), for a total of 505 HRUs. The management files for park and golf course HRUs were created by starting with the default PAST management file (no grazing operations or manure application), and adding fertilizer application rates appropriate for the land use type based on various research. See section “Fertilizer Application Data” below for more detail.

Table 2 Hybrid Land Use to SWAT Land Use Look-up Table

Hybrid Land Use SWAT Value Hybrid Land Use Description Code SWAT Description 1 20% - 39% (pct forest canopy) RNGB Range-brush 2 40% - 59% (pct forest canopy) FRSD Forest-deciduous 3 60% - 79% (pct forest canopy) FRSD Forest-deciduous 4 80% - 100% (pct forest canopy) FRSD Forest-deciduous 5 Residential (2000) URMD Residential-Medium Density 11 Open Water WATR Water 21 Low Intensity Residential URLD Residential-Low Density 22 High Intensity Residential URHD Residential-High Density Commercial / Industrial / 23 Transportation UCOM Commercial 32 Quarries / Strip Mines / Gravel Pits RNGE Range-grasses 41 Deciduous Forest FRSD Forest-deciduous 42 Evergreen Forest FRSE Forest-evergreen 43 Mixed Forest FRST Forest-mixed 81 Pasture / Hay PAST Pasture 82 Row Crops AGRR Agricultural Land - Row Crops 85 Urban / Recreational Grasses URLD Residential-Low Density 91 Woody Wetlands WETF Wetlands-forested 92 Emergent Herbaceous Wetlands WETL Wetlands

b) Final Land Use Scenario

A map showing the final land use scenario for the Big Darby Accord Planning area is included as Figure 4. Based on the land use descriptions for each category, a “look-up” table (Table 3) was created to convert the final land use scenario categories to the appropriate SWAT land use categories. To account for conservation development areas in SWAT, instead of creating entirely new SWAT land use categories, a revised GIS land use coverage was created to divide these conservation development areas into separate areas of range-brush and the appropriate residential land use category. The areas for the new range-brush regions were calculated cumulatively by sub-basin. Since the exact location of the open space (range-brush land use) within each conservation development area was unknown, the location of the open space areas were randomly selected within the conservation development areas and were simply drawn as circles of the correct size. A map showing this revised final land use scenario (converted to SWAT land use categories/codes) is included as Figure 5.

BIG DARBY ACCORD APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. / 7 The addition of the following land use codes/categories in SWAT was required to accurately model the final land use scenario: URR2, URM2, PARK, and GOLF. The two new urban land use codes were created by copying existing land use categories in the urban.dat SWAT database and making revisions to the urban land use parameters as necessary (see section “Urban Land Use Parameters”). The PARK and GOLF categories were simply created by copying and renaming the PAST category from the crop.dat SWAT database.

Table 3 Final Land Use to SWAT Land Use Look-up Table

Final Land Use Scenario SWAT Land Use Description Code SWAT Description Agricultural Use AGRR Agricultural Land - Row Crops Riparian Corridor FRSD Forest-deciduous Forest/Wooded Land FRSD Forest-deciduous Active Recreation Park Land PARK1 Park Open Space RNGB Range-brush Golf Course GOLF1 Golf Course Public/Institutional URM2* Suburban High Density Commercial UCOM Commercial Mixed Use UCOM Commercial Industrial UIDU2 Industrial Transportation UTRN Transportation Water Body WATR Water Rural Estate (< 0.2 DU/ac) PAST Pasture Rural (0.2-0.5 DU/ac) URR21 Rural residential Residential Conservation Development 50% URR21 (0.2-0.4 DU/ac) (+RNGB) Rural residential Residential Conservation Development 50% URLD (1 DU/ac) (+RNGB) Residential-Low Density Suburban Low Density (0.5-3 DUs/ac) URLD Residential-Low Density Suburban Medium Density (3 DUs/ac) URMD Residential-Medium Density Suburban Medium-High Density (5 DUs/ac) URM21 Suburban High Density Urban Medium Density (8 DUs/ac) URM21 Suburban High Density Urban High Density (>8 DU/ac) URHD Residential-High Density Special Residential LEEDS URMD Residential-Medium Density 1 New SWAT land use category created 2 UIDU land use code was not actually used in the final land use scenario model, due to the very small area of UIDU included in the final land use coverage and the land use thresholds used during the HRU delineation process

After the final land use scenario had been converted to the correct SWAT land use codes, the data was then used in conjunction with SSURGO soil data from the NRCS to create HRUs. A 3% threshold value for land use and a 12% threshold value for soil type were utilized to ensure that the land use scenario was represented effectively in the model while still limiting the total number of HRUs created. These threshold values resulted in a total of 684 HRUs being delineated for the entire modeling area.

8 / APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. BIG DARBY ACCORD 4. Initial Groundwater Pollutant Concentrations

Initial concentrations of nitrate and soluble phosphorus in the shallow aquifer for each 14-digit HUC were entered into SWAT using data provided by the OEPA from the Big Darby Creek TMDL study. A summary of these values is shown in Table 4.

Table 4 SWAT Initial Groundwater Pollutant Concentrations

Soluble Nitrate Phosphorus (mg N/L (mg P/L 14-digit HUC or ppm) or ppm) Hellbranch Run (220-010) 0.5351 0.0574 BDC 4 (200-010) 0.5537 0.0601 BDC 5 (200-020) 0.4635 0.0467 BDC 6 (220-020) 0.4451 0.0440 BDC 7 (220-030) 0.4888 0.0505

5. Agricultural Data

Input parameters regarding agricultural operations were generated in collaboration with OSU and the local NRCS office. Ten different agricultural management scenarios were created within the SWAT model, consisting of various three-year crop rotations of corn, soybeans, and/or winter wheat. For each of the three years in the rotation, approximately 30% to 40% of the crops grown are corn, 50% to 60% are soybeans, and 10% are winter wheat. The total number of heat units for each plant type to reach maturity was either the SWAT default value of 1,800 heat units or that recommended by the SWAT Potential Heat Unit Program, which estimates the heat units for crops based on local weather/climate conditions: x Corn – 1,800 heat units x Soybeans – 1,360 heat units x Winter wheat – 1,506 heat units The selected values were chosen based on the ability of the calibrated model to predict crop yields that were relatively close to historical crop yield statistics for Ohio (see Table 15).

The SWAT agricultural management scenarios also included tillage practices appropriate for the modeling area, based on information provided by the NRCS. For each of the three years in the rotation, approximately 30% of the crops grown utilize fall tillage, while about 70% use conservation tillage. The ten agricultural management scenarios were applied randomly to agricultural HRUs, such that each scenario was applied to a total of approximately 10% of the area within each 14-digit HUC (or partial HUC).

6. Fertilizer Application Data

a) Crops

The fertilizer application rates for agricultural lands were based on guidelines from the report “Tri-State Fertilizer Recommendations for Corn, Soybeans, Wheat and Alfalfa” (OSU Extension Bulletin E-2567). Values were then adjusted by about +/- 20% during the calibration process, to

BIG DARBY ACCORD APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. / 9 better correlate with the results from the OEPA GWLF model. The final values used in the model are still within an acceptable range and generally correspond to the range of application rates observed within the local area. All fertilizer was applied as elemental nitrogen and phosphorus; Application dates were selected to correspond to the dates used by OSU in its Olentangy TMDL agricultural management files/scenarios A summary of the annual fertilizer application rates is shown in Table 5.

Table 5 SWAT Annual Fertilizer Application Rates - Crops

Elemental Elemental Nitrogen Phosphorus Crop Type (kg/ha) (kg/ha) Corn 185 22 Soybean 20 15 Winter wheat 99 22

b) Livestock Manure Application

Using data provided from the OEPA for each 14-digit HUC, manure application from livestock was applied to pasture lands via both grazing operations and direct fertilizer application (manure collected from non-grazing animals year-round and from grazing animals during non-grazing seasons). All manure was applied to pasture/PAST land (versus agricultural/AGRR land), so that the amount of manure applied per unit area of pasture could remain constant for the final land use scenario model, according to the assumption that the number of livestock would increase/decrease in proportion to any increases/decreases in pasture. Grazing operation data is summarized in Table 6, while livestock manure application data is summarized in Table 7.

Table 6 Grazing Operations Data

Dry Mass 14-digit HUC Number of Animal Intake/Day Total Dry (portion within Livestock Number of Grazing Days Weight (% of body Mass Intake Franklin County) Type Livestock1 (Start Date)1 (kg) 1 weight) (kg/ha/day)5 2 Hellbranch Run Cattle 142 244 (Apr 1) 363 2.25% 1.096 3 (220-010) Horses 172 232 (Apr 1) 454 1.75% 1.291 Sheep 976 365 (Jan 1) 27 2.00% 4 0.502 Cattle 40 244 (Apr 1) 363 2.25% 2 0.920 3 BDC 4 (200-010) Horses 35 232 (Apr 1) 454 1.75% 0.782 Sheep 282 365 (Jan 1) 27 2.00% 4 0.432 Cattle 34 244 (Apr 1) 363 2.25% 2 0.648 3 BDC 5 (200-020) Horses 30 232 (Apr 1) 454 1.75% 0.556 Sheep 241 365 (Jan 1) 27 2.00% 4 0.306 Cattle 68 244 (Apr 1) 363 2.25% 2 1.717 3 BDC 6 (220-020) Horses 59 232 (Apr 1) 454 1.75% 1.448 Sheep 479 365 (Jan 1) 27 2.00% 4 0.806 Cattle 19 244 (Apr 1) 363 2.25% 2 0.751 3 BDC 7 (220-030) Horses 16 232 (Apr 1) 454 1.75% 0.615 Sheep 133 365 (Jan 1) 27 2.00% 4 0.350

10 / APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. BIG DARBY ACCORD 1 Source: OEPA (from TMDL analysis) 2 Source: http://ohioline.osu.edu/anr-fact/0002.html 3 Source: http://ohioline.osu.edu/b762/b762_12.html 4 Estimated value 5 Calculated value: Total Dry Mass Intake = (Number of Livestock x Animal Weight x Dry Mass Intake/Day) / Total Pasture area within 14-digit HUC

Table 7 Livestock Manure Application Data

Annual Dry Weight of Total Non- 14-digit HUC Manure Manure Non- grazing (portion within Livestock Number of Produced (kg/ Produced grazing Loading Franklin County) Type Livestock1 animal/day)2 (kg/ha/day)3 Days/Yr1 (kg/ha)4 Cattle 142 6.27 0.840 121 101.7 Hellbranch Run Horses 172 4.75 0.771 121 93.3 (220-010) Sheep 976 0.27 0.251 0 0 Hogs 312 1.25 0.368 365 134.3 Cattle 40 6.27 0.705 121 85.3 BDC 4 (200-010) Horses 35 4.75 0.467 121 56.5 Sheep 282 0.27 0.216 0 0 Hogs 88 1.25 0.309 365 112.8 Cattle 34 6.27 0.497 121 60.1 BDC 5 (200-020) Horses 30 4.75 0.332 121 40.2 Sheep 241 0.27 0.153 0 0 Hogs 76 1.25 0.221 365 80.8 Cattle 68 6.27 1.316 121 159.3 BDC 6 (220-020) Horses 59 4.75 0.865 121 104.7 Sheep 479 0.27 0.403 0 0 Hogs 150 1.25 0.579 365 211.2 Cattle 19 6.27 0.576 121 69.7 BDC 7 (220-030) Horses 16 4.75 0.367 121 44.4 Sheep 133 0.27 0.175 0 0 Hogs 42 1.25 0.254 365 92.6 1 Source: OEPA (from TMDL analysis) 2 Source: Wet weights (lb/animal/day) from OEPA TMDL analysis; Converted to dry weights using conversion rates from http://www.metrokc.gov/dchs/csd/wsu- ce/agriculture/PDFs/ManureGuide.pdf 3 Calculated value: Total Manure Produced = (Number of livestock x Dry Weight of Manure Produced) / Total Pasture area within 14-digit HUC; These values were used for the SWAT grazing operations as required; they were also then used to calculate the annual non-grazing loadings. 4 Calculated value: Annual Non-grazing Loading = (Total Manure Produced x Non-grazing Days/Yr); These annual loadings were then separated into four separate manure application dates according to the dates and percentages used in the OEPA TMDL analysis. These dates (and corresponding percent of annual loadings) were: for cattle, Apr 1 (20%), May 1(20%), Oct 1(30%), and Nov 1(30%); for hogs, 1 (10%), May 1(10%), Oct 1(40%), and Nov 1(40%); and for horses, Jan 1 (25%), Feb 1 (25%), Mar 1 (25%), Dec 1 (25%).

BIG DARBY ACCORD APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. / 11 c) Lawns

For the pervious parts of all urban land uses, fertilizer type, application dates, and amounts were set according to an OSU Extension Fact Sheet discussing recommended lawn fertilizer application specific to the state of Ohio. Selecting a fertilizer with an approximate 5:1:2 ratio, the 25-5-0 fertilizer from the default SWAT fertilizer database was chosen (disregarding K, since this pollutant was not specifically studied in the model). The application recommendations for similar fertilizers (24-4-8 and 24-4-12) were then utilized. The final lawn fertilizer application information used in the SWAT model is summarized in Table 8.

Table 8 SWAT Fertilizer Application Rates - Lawns

25-5-0 Application Date (kg/ha) May 1 98 July 1 146 Sept 1 195 Nov 1 293

d) Recreational Fields/Parks

For active recreational park lands, the fertilizer type, application dates, and amounts were based on recommendations for recreational/sports fields published by the OSU Extension and by Purdue University. First, the 24-6-0 fertilizer was selected from the SWAT database, since this most closely matched the 4:1:2 and 4:1:3 ratios recommended by the OSU Extension (disregarding K, since this pollutant was not specifically studied in the model). The dates and application rates used in the SWAT model are shown in Table 9.

Table 9 SWAT Fertilizer Application Rates - Recreational Fields/Parks

24-6-0 Application Date (kg/ha) Jun 1 203 Aug 20 203 Sept 20 203 Nov 20 305

e) Golf Courses

For active golf courses, the fertilizer type, application dates, and amounts were based on recommendations published by the Virginia Cooperative Extension and by the Delaware Department of Natural Resources and Environmental Control. First, the 28-10-10 fertilizer was selected from the SWAT database, since this is between the recommended 4:1:2 and 4:2:4 ratios from the Virginia report (disregarding K, since this pollutant was not specifically studied in the model). The recommended total nitrogen application rates for greens, tees, fairways, and rough areas are summarized in Table 10.

12 / APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. BIG DARBY ACCORD Using estimated percentages of these areas within each golf course (derived using Franklin County orthophotos), a composite annual fertilizer application rate for golf courses was then estimated as: Total Annual 28-10-10 Loading (lb/1000 sq ft/yr) = (0.05)(35) + (0.03)(14.29) + (0.70)(10.71) + (0.22)(3.57) = 10.46. Converted to kg/ha, this composite value was then divided into five equal applications of 102.1 kg/ha on May 1, May 15, June 1, June 15, and July 1.

Table 10 Recommended Annual Fertilizer Application Rates - Golf Courses

Annual Estimated Recommended 28-10-10 Percentage Total N Application of Total Golf Course (lb/1000 (lb/1000 Golf Course Area sq ft/yr) sq ft/yr)1 Area2 Greens 9.8 35.00 5% Tees 4 14.29 3% Fairways 3 10.71 70% Rough 1 3.57 22% 1 Calculated as Total N/0.28 2 Estimated using Franklin County orthophotos

7. Urban Land Use Parameters

a) Build-up/Wash-off Parameters

For the impervious portions of urban lands, the build-up/wash-off algorithms within SWAT were used; however, the default values for nutrient concentrations and time to reach one-half of the maximum build-up were adjusted in order to better correspond with values used by the GWLF model. Thus, the build-up/wash-off calculations from the SWAT model more closely matched those predicted in the Big Darby TMDL analysis. Table 11 summarizes the build-up/wash-off parameters from the SWAT urban.dat file that were revised.

Table 11 Revised SWAT Build-up/Wash-off Parameters

Time to Reach SWAT Land 1/2 Maximum Use Code TN (ppm) TP (ppm) Build-up (days) URR2 1,076 136 5 URLD 2,466 312 5 URMD 3,408 431 5 URM2 4,664 590 5 URHD 5,830 738 5 UCOM 12,944 1,443 5 UTRN 14,793 1,650 5

b) Runoff Curve Numbers and Percent Impervious Values

Curve numbers and percent impervious values for various land uses within SWAT were determined based on documentation for the Natural Resources Conservation Service (NRCS) TR- 55 program, which performs hydrologic calculations for small, urban watersheds. The revised

BIG DARBY ACCORD APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. / 13 percent impervious values were implemented within SWAT by actually overwriting the CN2 values in the management files for each HRU. The revised percent impervious values were implemented by editing the default values in the urban.dat file. The CN2 and percent impervious values used are shown in Table 12.

Table 12 Revised SWAT Runoff Curve Numbers and Percent Impervious Values

SWAT Runoff Curve Number (CN2) Directly Land by Soil Hydrologic Group Total Connected Use Impervious Impervious Code Description A B C D (%) (%) AGRR Agricultural Land-Row Crops 62 71 78 81 NA NA FRSD Forest-deciduous 36 60 73 79 NA NA PAST Pasture 39 61 74 80 NA NA GOLF Golf Course 39 61 74 80 NA NA PARK Park 39 61 74 80 NA NA RNGB Range-brush 35 56 70 77 NA NA URR2 Rural Residential 47 66 77 81 12 10 URLD Residential-Low Density 56 71 80 85 27.5 24 URMD Residential-Medium Density 61 75 83 87 38 30 URM2 Suburban High Density 69 80 87 90 52 48 URHD Residential-High Density 77 85 90 92 65 49 UCOM Commercial 89 92 94 95 85 80 UTRN Transportation 98 98 98 98 98 95

E. Calibration/Baseline Model

The SWAT baseline model was first calibrated for flow to the USGS gage along Hellbranch Run. The calibrated model flow volumes were within 1.5 % of the USGS Hellbranch gage’s values and produced R2 values of approximately 0.7 and 0.6 for average annual and average monthly flows, respectively. The R2 values can, in part, be attributed to several instances in the dataset where measured precipitation did not coincide with observed flow at the HB gage and vice versa.

Pollutant loads in the stream (phosphorous, nitrogen, and total suspended solids) were calculated in SWAT based on the volume of runoff and groundwater flow entering the stream in conjunction with the following inputs: fertilizer application on agricultural land, parks, golf courses and pervious portions of urban land; manure application on pasture; build-up/wash-off pollutants from impervious portions of urban land; and initial concentrations of nitrates and soluble phosphorus in the shallow aquifer. Point source pollutant loadings from OEPA’s TMDL model were not entered into the model. The model was then calibrated to the EPA’s GWLF model results for Total Nitrogen (TN), Total Phosphorous (TP), and Total Suspended Solids (TSS). All calibration operations were performed using data for the Hellbranch Run sub-watershed.

The parameters and values used to calibrate the baseline model are summarized in Table 13. Results of the calibration are presented in Table 14 (pollutant values are average annual loadings for the calibration period).

14 / APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. BIG DARBY ACCORD BIG DARBY ACCORD APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. / 15 (Pg 2 of Table 13 inserted here; see Table13_CalibrationParameter.xls)

16 / APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. BIG DARBY ACCORD Table 14 Calibration Model Results

Volume Description (mm) Q (cfs) SF/BF (%) TN (kg) TP (kg) TSS (kg) USGS Hellbranch 52/48 to Run gage 348.7 39.8 70/301 NA NA NA OEPA's GWLF model NA NA 59/412 212,3203 15,2973 3,085,2303 SWAT Baseline model 344.4 39.3 54/46 190,200 14,706 3,439,721

Percent Error -1.2%4 -1.3%4 NA -10.4%5 -3.9%5 11.5%5 mm – millimeters cfs – cubic feet per second SF/BF – surface flow/baseflow 1 Range derived using SWAT Baseflow Separation program 2 Published value in draft Big Darby Creek TMDL report for Hellbranch Run sub-watershed (220-010) 3 Does not include point source data that was added outside of GWLF to yield published TMDL “Existing” pollutant loadings; GWLF data corresponds to the SWAT model’s calibration period (study years 3-10, Apr 1996 through Mar 2004) 4 Compared to USGS Hellbranch Run gage data 5 Compared to OEPA GWLF values

In addition to the calibration results shown in Table 14, as a check to determine the relative accuracy of the parameters associated with agricultural row crops, crop yields predicted by the model were compared to crop yield statistics for Franklin County. Table 15 demonstrates that crop yields, and therefore crop parameters, are relatively accurate since the SWAT yields are generally within 10% of the historical yields for each crop type.

Table 15 SWAT Crop Yields Compared to Historical Data

Average Crop Average Crop SWAT Crop Yields for Yields for Yields (kg/ha), Ohio, 1997- Ohio, 1997- Calibrated Crop 2003 (bu/ac)1 2003 (kg/ha)2 Model Corn 125 7,822 6,892 Soybeans 39 2,587 2,308 Winter Wheat 69 4,668 3,299 1 Source: USDA National Agricultural Statistics Service (http://www.nass.usda.gov/Statistics_by_State/Ohio/index.asp) 2 Conversion from bu/ac to kg/ha, assuming 56 lb/bu for corn, 60 lb/bu for soybeans and winter wheat

The results of the calibration modeling serve as the basis for comparison with the results of the final land use scenario modeling, described below. This comparison allows for a determination of the changes in pollutant loading within the study area corresponding with only the changes in land use associated with the final land use plan associated with the Big Darby Accord.

BIG DARBY ACCORD APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. / 17 F. Final Land Use Scenario Model

The final land use scenario model was established from the baseline (calibration) model by changing the land use coverage to reflect projected build-out conditions within the Accord planning area, considering various development types and housing densities along with their location. The fundamental changes related to the final land use scenario are described below.

1. Converting existing agricultural land uses to a variety of urbanized land uses, varying from a low density (rural) residential to a commercial level of development. 2. Converting existing agricultural land uses to preserved open space (conservation areas).

For areas outside of the Accord planning area, the baseline land use data was used, since build- out conditions were not projected for these regions.

The results of the final land use scenario model along with results from the calibration model are summarized in Table 16. Data is categorized by each 14-digit HUC (or portion of) within the modeling study area. For the Hellbranch sub-watershed only, published values from the Big Darby Creek draft TMDL report are also included. To be able to compare the SWAT results to these TMDL values, additional TN and TP point source loadings that were added to the GWLF results to yield the published “Existing” pollutant loadings in the TMDL report were also added to the SWAT results. The TSS values reported in the TMDL are cumulative values that account for both sediment yield from overland runoff (predicted by the GWLF model) and a larger amount of sediment from channel degradation and construction activities (estimated by the OEPA outside of GWLF). The SWAT model, similar to GWLF, accounts only for sediment related to overland runoff. The parameters that dictate bank erosion are site specific, and this information did not exist at the time of calibration. Therefore, sediment produced by channel degradation and construction runoff was not estimated as a part of these water quality modeling efforts. TSS from construction/channel erosion is assumed to be the same as that estimated for the TMDL analysis.

TMDL allowable values for the other 14-digit sub-watersheds are not provided in the table below because the Accord planning area and, therefore, the area modeled within the SWAT analysis, does not include the entire extent of those 14-digit HUCs. As such, it is not logical to report the allowable values from the TMDL report for those areas, nor is it feasible to estimate the proportion of the published allowable values that are attributed to only a portion of the 14-digit HUC.

18 / APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. BIG DARBY ACCORD Table 16 Comparison of Pollutant Loading Values

Hellbranch Run (220-010) Overland Construction/ Volume Q SF/BF Runoff Channel Erosion Description (mm) (cfs) (%) TN (kg) TP (kg) TSS (kg) TSS (kg)

TMDL Existing NA NA 59/41 NA 16,359 3,051,200 17,594,074 TMDL Allowable NA NA NA NA 3,175 1,086,249 SWAT Baseline model + PS 344.4 39.3 54/46 190,885 15,944 3,439,721 17,594,074 SWAT Future Land Use Scenario model + PS 369.8 42.2 62/38 113,617 4,517 1,023,087 17,594,074 PS – Point Source Loading (additional TN and TP loadings calculated by OEPA that were added to GWLF results to yield TMDL Existing values)

BDC 4 (200-010) Overland Volume Runoff Description (mm) Q (cfs) SF/BF (%) TN (kg) TP (kg) TSS (kg) SWAT Baseline model 351.7 11.0 46/54 47,985 3,938 454,960 SWAT Future Land Use Scenario model 346.6 10.8 44/56 20,019 582 184,825

BDC 5 (200-020) Overland Volume Runoff Description (mm) Q (cfs) SF/BF (%) TN (kg) TP (kg) TSS (kg) SWAT Baseline model 341.6 20.0 48/52 83,537 7,038 1,903,448 SWAT Future Land Use Scenario model 344.5 20.1 49/51 36,393 1,175 427,247

BDC 6 (220-020) Overland Volume Runoff Description (mm) Q (cfs) SF/BF (%) TN (kg) TP (kg) TSS (kg) SWAT Baseline model 331.1 37.1 50/50 163,813 16,230 8,548,723 SWAT Future Land Use Scenario model 335.1 37.6 50/50 93,456 6,840 6,858,007

BIG DARBY ACCORD APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. / 19 Entire SWAT Modeling Area Overland Volume Runoff Description (mm) Q (cfs) SF/BF (%) TN (kg) TP (kg) TSS (kg) SWAT Baseline model 338.2 81.3 64/36 382,681 34,148 18,462,134 SWAT Future Land Use Scenario model 354.6 85.3 68/32 228,523 11,882 10,283,179

G. Conclusions

The modeling provided has been successful in duplicating the results from the TMDL study, at least for the Hellbranch Run sub-watershed. With that modeling serving as a baseline for comparison, it has been determined that the proposed land use plan for the Big Darby Accord will ultimately reduce the level of pollutants that are contained in stormwater runoff and discharged to Hellbranch Run or directly to the Big Darby Creek main stem. The percent reduction in the various pollutants for Hellbranch Run and for the larger study area is contained in Table 17, below. As expected, the increase in impervious area associated with the urbanizing land uses contained within the final land use plan will increase the calculated average annual flow rate and cause a re-distribution of the surface flow/baseflow relationship within the study area.

Table 17 Comparison of Baseline Condition to Final Land Use Plan

Percent Loading Reduction1 Pollutant Hellbranch Run Watershed Entire Study Area2 TSS3 70% 44% TP 72% 65% TN 41% 40% 1Compared to SWAT Baseline model 2Includes areas directly tributary to Big Darby Creek 3Pertains only to the overland runoff component of TSS

The percent reductions noted in Table 17 for the Hellbranch Run watershed are less than those specified in the TMDL to obtain the target levels for those pollutants. [Note: TN is not presented in the TMDL.] Furthermore, the comparison of TSS only pertains to the overland runoff component of that pollutant. Table 16 contains additional information relating the additional loading associated with construction activities and channel bank erosion. Considerations to reduce these individual components include comprehensive erosion and sediment control criteria and incentives to promote stream bank stabilization and/or restoration activities within the watershed.

It is important to note that the results represented by the SWAT modeling and summarized within this document represent only an analysis of land use changes within the Accord planning area and do not account for stormwater best management practices or specific site planning practices, such as low-impact design, that would further reduce pollutant loading or increase infiltration from urbanizing land uses. Other important observations regarding the modeling and the accompanying results are described below.

x The significant reduction in pollutants when comparing the final land use plan to the baseline condition can be attributed not only to the replacement of agriculture with

20 / APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. BIG DARBY ACCORD urbanizing land uses, but also the representation of conservation open space that is part of the plan and also replaces a considerable amount of land currently being used for agriculture. x The analysis performed for this study did not represent the presence of field tile that exists in conjunction with agricultural land uses throughout the study area. Eliminating field tile in conjunction with changing land uses would likely reduce the change in flow rate and the surface flow/baseflow relationship. x Stream restoration activities can have a beneficial impact on multiple facets of the modeling provided for this study. Stream restoration to add floodplain storage can mitigate the impact of increased flow associated with urbanizing areas. It can also increase the assimilative capacity of pollutants conveyed within the stream channel, particularly TSS.

BIG DARBY ACCORD APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. / 21 22 / APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. BIG DARBY ACCORD BIG DARBY ACCORD APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. / 23 24 / APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. BIG DARBY ACCORD BIG DARBY ACCORD APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. / 25 26 / APPENDIX A — FINAL MODELING STUDY / EMH&T, INC. BIG DARBY ACCORD Big Darby Accord Best Management Practice Pilot Study Report

EMH&T, Inc. June 2006

Table of Contents

A. Introduction……...... 2 B. SWAT Analysis of Pilot Study Development Area ...... 2 C. Post-SWAT Analysis of BMPs ...... 3 D. Application of Results...... 5 E. Conclusions…………………………………………………………….....6

Table No. 1 - Summary of SWAT Modeling for Pilot Study………………..3 Table No. 2 - BMP Removal Efficiencies…………………………………...4

Figure 1 - Pilot Study Area (SWAT Land Use) Figure 2 - Town Center Design Figure 3 - Medium Density and Multi-Family Housing Figure 4 - Low Density Single-Family Residential Figure 5 - High Density Single-Family Residential and Big-Box Retail Figure 6 - Neighborhood Retail

BIG DARBY ACCORD APPENDIX A — FINAL PILOT STUDY MODEL / EMH&T, INC. / 1 A. Introduction

The SWAT model that was prepared for the final land-use plan did not include a representation of any stormwater BMPs, and the results of the modeling were compared to similar locations within the OEPA Total Maximum Daily Load (TMDL) report. For example, SWAT model results were compared to the TMDL results for the entire Hellbranch Run watershed. A pilot study was undertaken in an effort to more closely review the results of the SWAT modeling of one sub-watershed within the Hellbranch Run watershed and to provide an analysis of stormwater BMPs for the pilot study area, in this way, the pilot study analysis would examine a possible template for meeting the proposed water quality performance goals for the planning area.

The BMP pilot study was focused on the Town Center area of the most recent Darby Accord land use plan. The Town Center is located within sub-basin 43 of the overall SWAT model and is tributary to McCoy Ditch, within the Hellbranch Run watershed. Refer to Figure 1 for a representation of the pilot study area.

B. SWAT Analysis of Pilot Study Development Area

The structural BMPs that are part of the BMP Toolkit in the land use plan cannot be modeled within the SWAT model platform. Two of the non-structural BMPs that are part of the Low Impact Development parameters can be directly analyzed within SWAT: 1) a reduction in directly connected impervious area (DCIA), and 2) the use of filter strips (vegetated buffers along streams). A reduction of DCIA is indicative of a development that has less downspout to gutter to storm sewer connections and the filter strips are representative of a storm water conveyance system discharging into a dedicated stream side riparian area prior to entering a stream channel.

DCIA is represented by a percentage of the total impervious surface that is considered directly connected, for example, if a site is 20% impervious cover and the DCIA is 90%, then 90% of the 20% impervious cover is directly connected and is defined within the “urban.dat” file of the SWAT program. The SWAT manual includes information on a range of values for DCIA for different land use types based on research done on several sites in Wisconsin and Michigan (page 477 of the Input/Output File Documentation manual). The calibrated model utilizes numbers for DCIA that are close to the averages listed in the SWAT manual. For the purposes of the pilot study, the DCIA percentage was lowered to the lowest value listed in the SWAT manual for each of the urban land-use types in the pilot study area. The lowest limit for DCIA takes into account practical limitations on disconnecting impervious surfaces, for example, it is not practical to disconnect sidewalk runoff from driveway runoff, and to disconnect driveway runoff from street runoff.

The results of the reduction in DCIA, and the impact on each of the pollutants of concern, are summarized in Table No. 1. In comparing the results of the DCIA reduction modeling to the final land use plan modeling, an increase in TSS, phosphorous, and nitrogen is present. Upon further study of the modeling output, this increase is present only from the commercial areas, which is likely due to the manner in which pollutants buildup on paved surfaces before being washed off during a rain event. In general, a decrease in pollutants is realized by disconnecting impervious surfaces on all land uses except for commercial development, however, it is not enough to eliminate the need for other BMPs on the site that would have a larger impact on pollutant removal rates.

In addition to DCIA, the impact of filter strips on the pollutant loads was analyzed in SWAT. Within SWAT, a filter strip width is defined within the management file for each HRU. SWAT utilizes a simple

2 / APPENDIX A — FINAL PILOT STUDY MODEL / EMH&T, INC. BIG DARBY ACCORD equation to determine the pollutant removal efficiency for a filter strip which it applies equally to total suspended solids (TSS) and nutrients (phosphorous and nitrogen). The equation is:

0.2967 trapef = 0.367*(widthfilstrip)

Where trapef is the fraction of the pollutant loading trapped by the filter strip, and widthfilstrip is the width of the filter strip in meters

Two different widths were analyzed, 10 meters and 20 meters, and the results of this analysis are also summarized in Table No. 1 below. It should be noted that by utilizing the equation in the SWAT theory manual (pg. 325) for the removal efficiency of filter strips, a 25 meter (82 feet) wide filter strip would meet the 95% removal target for TSS, with no other BMP application. After reviewing the results of the filter strip modeling it is possible that the model is over-simplifying the processes that occur within a filter strip and, therefore, over-estimating the removal efficiency that can be achieved through their use.

Table No. 1 Summary of SWAT Modeling for Pilot Study Scenario TSS (kg) % Reduction Total P % Reduction Total N % Reduction from Existing (kg) from Existing (kg) from Existing Existing 2,302,169.14 NA 1,602.19 NA 18,260.50 NA Final Plan 301,310.34 86.9 483.66 69.8 9,641.87 47.2 10 Meter Filter 116,091.96 95.0 239.22 85.1 5,791.58 68.3 Strip 20 Meter Filter 73,798.50 96.8 183.45 88.6 4,703.69 74.2 Strip Reduced DCIA 310,159.67 86.5 516.07 67.8 9,897.37 45.8 Reduced DCIA & 20 meter 74,763.70 96.8 187.72 88.3 4,839.30 73.5 filter strip

The analysis of the SWAT model output from the pilot study area is based on pollutant loading numbers from each individual HRU before they are routed and transported downstream, and should not be compared to the Hellbranch Run output that was used for calibration purposes. As runoff is routed downstream in the SWAT model attenuation of pollutant loads and runoff peak flows are accounted for, the results summarized above are prior to any of that attenuation occurring. The results presented above are useful for comparative purposes for the pilot study area, and specifically for the BMPs analyzed within the SWAT model.

C. Post-SWAT Analysis of BMPs

In order to determine which BMPs will be necessary to meet the target pollutant removal rates from the TMDL report, analysis outside of the SWAT model was performed. In 2004 the State of Georgia developed the Georgia Stormwater Management Manual Stormwater Quality Site Development Review Tool as a method for both designers and reviewers to determine whether or not a proposed BMP or combination of BMPs would meet the requirements for removal of TSS that the State of Georgia requires. The State of Georgia has an 80% TSS removal as their primary pollutant removal goal, and other pollutants are secondary. As part of this tool, it is possible to link multiple BMPs in sequence and determine the cumulative benefit of the “treatment train” of BMPs. As part of the tool, Georgia includes an instruction manual which includes the equations used to determine the diminishing benefit of BMPs in series. For example, if two BMPs are in series, and individually they can remove 80% of the TSS load, when placed in series the first will remove 80% of the TSS, but the second will not remove 80% of the final 20% of the TSS, which would be a total removal efficiency of 96%. The calculator determines that

BIG DARBY ACCORD APPENDIX A — FINAL PILOT STUDY MODEL / EMH&T, INC. / 3 two combined BMPs will remove approximately 88% of the total TSS load. The diminishing affect of the treatment train concept is attributed mostly to the finer (smaller) particles that are not captured in the initial BMP and less likely to be captured by the second. Information contained within the Georgia tool references previously determined removal efficiencies of the various BMPs, and the removal efficiencies have no correlation to land use. For example, if a Stormwater Wetland is the selected BMP, an 80% removal of TSS can be achieved regardless of the land use type that provides runoff to that feature. TSS and phosphorus (P) removal efficiencies for certain individual BMPs used within the tool are summarized in Table No. 2, below.

Table No. 2 BMP Removal Efficiencies Structural Control TSS Removal (%) Total P Removal (%) Stormwater Pond 80 50 Stormwater Wetland 80 40 Bioretention Area 80 60 Infiltration Trench 80 60 Enhanced Swales 80 50 Filter Strip 50 20 Grass Channel 50 25

The Georgia tool was used to determine which BMPs used in conjunction with one another would be able to reach the Big Darby Creek TMDL target goal of 95% removal of TSS. TSS removal was the focus for the pilot study analysis as it is the primary pollutant targeted by the design tool being used, and has the highest standard for removal in the TMDL.

Two different scenarios were considered, one utilizing BMPs that would be more likely within a residential development, and one that would be more typical of a commercial development. Both scenarios are built on the concept of a treatment train, assessing multiple BMPs applied in combination. The scenarios below are shown with multiple different removal efficiencies, starting at 80% (which is a common goal in other stormwater management guidelines), and proceeding up to the 95% goal of the TMDL. These different efficiencies require different numbers of BMPs to meet the goal, and are therefore listed in order of which BMPs are the most likely to be implemented to meet a specific goal. For example, on a residential development, if the goal were to meet 80% removal of TSS only a stormwater wetland would be needed, but if 85% were required a stormwater wetland and an enhanced swale would be necessary. This method was utilized due to ongoing discussion regarding the target for water quality protection. There is a possibility that due to the large conservation areas required in the final land use plan that a 95% removal of TSS would not be required, and that a different removal rate would become the goal for the BMPs to achieve. It is recommended that a minimum removal efficiency of 80% be used on all development sites.

The results of the treatment train analysis are presented below.

Residential Land Use Area: x To meet 80% removal: Stormwater Wetland x To meet 85% removal: 80% + Enhanced Swale (which reaches 88%) x To meet 90% removal: 85% + Enhanced Swale x To meet 95% removal: 90% + either Bioretention or an Infiltration Trench

This listing above does not take the order of the BMPs into account, which would likely be:

4 / APPENDIX A — FINAL PILOT STUDY MODEL / EMH&T, INC. BIG DARBY ACCORD Bioretention to Enhanced Swale to Stormwater Wetland to Enhanced Swale

Commercial Land Use Area: x To meet 80% removal: Bioretention x To meet 85% removal: 80% + Infiltration Trench (which reaches 88%) x To meet 90% removal: 85% + Filter Strip x To meet 95% removal: 90% + Stormwater Wetland and an Enhanced Swale (which reaches 96%)

The more likely order would be: Filter Strip to Bioretention to Infiltration Trench to Stormwater Wetland to Enhanced Swale.

D. Application of Results

As part of the final land use plan, the Town Center area is expected to be an area of high population density and a mix of different housing types and commercial uses. Projections were made about the composition and arrangement of development within the Town Center area in order to facilitate the modeling of the area for both the final land use plan model and the pilot study modeling. Figure 1 has been prepared to show the configuration of proposed land use within the Town Center area that has been used to perform the SWAT analysis of that condition. Figure 2 has been prepared to show a more detailed depiction of that proposed land use with a conceptual representation of stormwater management applications.

After comparing the results of the analysis to determine which BMPs would be necessary to meet the TMDL goal of 95% removal of TSS and the proposed conceptual configuration of the Town Center, it became apparent that it may be impractical for certain development types to incorporate all of the BMPs that would be necessary to meet the TMDL target. For example, a small commercial development site would be unlikely to have enough space to incorporate 5 separate BMPs without compromising the ability to feasibly develop the site. Furthermore, the proliferation of numerous smaller BMP applications presents a concern regarding long term maintenance and viability. These realizations, coupled with the projected development composition of the Town Center area led to the development of a more regionalized BMP implementation process. In the regional system, the stormwater BMPs that are physically larger and occupy more land area would be considered the regional BMPs that would provide for a portion of the water quality control, and much of the quantity control for a development area.

Using the BMP treatment train concept outlined above for commercial and residential development, the regional system would likely be the last two or three BMPs in the train, while the initial BMPs would be included within individual development sites, as illustrated in the diagram below.

Residential Development

On-site BMP: Bioretention and Enhanced Swale Regional System: Receiving Stormwater Wetland and Stream Enhanced Swale Commercial Development

On site BMP: Filter Strip Bioretention and Infiltration Trench 5

BIG DARBY ACCORD APPENDIX A — FINAL PILOT STUDY MODEL / EMH&T, INC. / 5 In an effort to determine what some of these BMPs could potentially change in the appearance of different types of development, Figures 3 through 6 were created using existing developed areas within Franklin County. None of these developments is located within the planning area, nor are any retrofit projects expected from these Figures. The Figures were created for illustrative purposes only to show how development would have to be altered to incorporate a treatment train of stormwater BMPs. As development density increases it requires more creativity on the part of the site designer to incorporate some of the required BMPs, but as shown on the Figures is possible. Figures 3 through 6 show BMPs that are not primary BMPs for a site, like pervious pavement, that have the possibility to reduce the overall size of required runoff quantity control by increasing the portion of the post development runoff that is allowed to infiltrate into the soil. These secondary BMPs are shown for illustrative purposes only and will not be required, but may be encouraged, for any development.

E. Conclusions

The pilot study was undertaken to allow for a greater understanding of the impact of stormwater BMPs on the pollutant loads that are produced by urban runoff. This was done through two different methods, by analyzing results from the SWAT modeling performed for the final land use plan, and through the use of a tool developed for use in the State of Georgia to determine the BMPs necessary on a site to meet a TSS removal requirement. Based on the analysis performed, a treatment train of BMPs will likely be required to meet the current pollutant targets for the Darby Accord planning area. The information gathered regarding this treatment train method of controlling water quality led to the realization that regional stormwater BMPs have the ability to allow for a higher density development in the area tributary to the BMPs by minimizing the area required for BMPs on individual development sites.

The final land use plan indicated, and the pilot study model reinforces, that by enabling land use change, a significant reduction in pollutant loads can be achieved. This would indicate that any post-development stormwater BMPs implemented in the developed condition may not have to meet the removal efficiency shown in the TMDL. The pollutant removal requirements (for TSS and phosphorous) listed in the TMDL are from the existing condition for the planning area, and the implementation of the land use plan will likely account for a portion of the removal requirement for those pollutants. Certain land use types reduce TSS, but may increase phosphorous, and other land use types may do the opposite. The final removal efficiency required for post-development BMPs will likely vary somewhat by land use type, with sites that have a higher pollutant loading potential requiring a removal efficiency closer to the 95% required by the TMDL.

Based on the pilot study analysis, minimizing directly connected impervious areas does provide a benefit to water quality and should be encouraged, it does not eliminate the necessity for other BMPs for a site. While filter strips were shown to provide a marked decrease in the pollutant load to the streams, the results may exaggerate the actual benefit provided. So, like minimizing DCIA, it is a practice that should be encouraged, but will not eliminate the need for additional BMPs as part of the development.

Details regarding the implementation of a regional stormwater system and the related BMP treatment train must be resolved, including who constructs the regional portions of the system and the timing of the construction of the regional system in relation to the rest of the development that will be tributary to it. These issues and others will need to be addressed before any regional stormwater system is implemented within the planning area. Furthermore, more specific allowable pollutant load rates are being developed at this time to provide additional design guidance for site-specific or regional-based stormwater BMPs. .

6 / APPENDIX A — FINAL PILOT STUDY MODEL / EMH&T, INC. BIG DARBY ACCORD BIG DARBY ACCORD APPENDIX A — FINAL PILOT STUDY MODEL / EMH&T, INC. / 7 8 / APPENDIX A — FINAL PILOT STUDY MODEL / EMH&T, INC. BIG DARBY ACCORD BIG DARBY ACCORD APPENDIX A — FINAL PILOT STUDY MODEL / EMH&T, INC. / 9 10 / APPENDIX A — FINAL PILOT STUDY MODEL / EMH&T, INC. BIG DARBY ACCORD BIG DARBY ACCORD APPENDIX A — FINAL PILOT STUDY MODEL / EMH&T, INC. / 11 12 / APPENDIX A — FINAL PILOT STUDY MODEL / EMH&T, INC. BIG DARBY ACCORD Resource Management Development Recreation Other Sites Trails Prevention Ordinances Maintenance Development Rehabilitation Streetscaping Improvements Wildlife Habitat Future Planning Future Restoration and Restoration Management and Management Facility and Service Facilities/ Amenities

Organization / Agency and Grant or Protection Farmland and Planning Future Land Acquisition/Open Land Acquisition/Open Conservation Corridors Conservation Pollution Control/ Water Water Control/ Pollution Rehabilitation of Existing Existing of Rehabilitation Education / Interpretation / Education Quality/Stormwater/Flood Quality/Stormwater/Flood Community and EconomicCommunity General Operating Budget Budget General Operating Space/Resource Protection Space/Resource

Program Website/Contact Restoration) (Rehabilitation/ Recreational Areas or Fields Recreational Neighborhood Revitilization / / Neighborhood Revitilization

Federal Agencies and Programs

Federal Emergency Management Agency http://www.fema.gov/fima/planning.shtm DDDD

National Park Service

Rivers, Trails, and Conservation Assistance http://www.ncrc.nps.gov/rtca/ Program DD North American Wetlands Conservation http://www.nature.nps.gov/water/NorthAmWetlands Act Grants Program ConsActGrantsProgram.doc DDDD

US Army Corp of Engineers http://www.usace.army.mil/public.html D DDD

US Department of Agriculture/Natural Resources Conservation Service

Conservation Reserve Program http://www.fsa.usda.gov/dafp/cepd/crp.htm DDDDD http://www.oh.nrcs.usda.gov/programs/csp_06/csp_ Conservation Security Program home_2006.html DD http://www.oh.nrcs.usda.gov/programs/CIG/cig2006. Conservation Innovation Grants (CIG) html http://www.fsa.usda.gov/pas/publications/facts/html/ Emergency Conservation Program ecp04.htm DD Farmland Protection Program http://www.info.usda.gov/nrcs/fpcp/fpp.htm DD D http://www.oh.nrcs.usda.gov/programs/grp/grasslan Grassland Reserve Program d_res_2003.html DDDD Wetlands Reserve Program and Wetlands http://www.nrcs.usda.gov/programs/wrp Reserve Enhancement Program DDD Wildlife Habitat Incentives Program http://www.oh.nrcs.usda.gov/programs/whip/whip_2 (WHIP) 006.html DD Cooperative Conservation Partnership http://www.oh.nrcs.usda.gov/programs/eqip/eqip200 Initiative (CCPI) 6.html Environmental Quality Incentives Program http://www.oh.nrcs.usda.gov/programs/eqip/eqip200 (EQIP) - National 6.html DD Resource Conservation and Development http://www.oh.nrcs.usda.gov/programs/RCD/index.ht (RC&D) Program ml DDDD

US Department of Housing and Urban http://www.hud.gov/offices/adm/grants/fundsavail.cf Development m#grants DDDDD

US Department of the Interior http://www.nbc.gov/cci/matrix.cfm DD DD DDDDD

US Department of Transportation http://www.fhwa.dot.gov/reauthorization/safetea.htm D D DDDD

US Environmental Protection Agency http://www.epa.gov/epahome/grants.htm DDDD D Water Resource Restoration Sponsor Program www.epa.state.oh.us/defa DDDD

Non source Program and Grants http://www.epa.gov/owow/nps/cwact.html D

US Fish and Wildlife http://www.fws.gov/grants

http://endangered.fws.gov/grants/private_stewardshi Private Stewardship Grants p.html DD

State Agencies and Programs

Ohio Department of Natural Resources http://www.dnr.state.oh.us/grants.htm (ODNR) Division of Real Estate and Land Management Natureworks 614-265-6646 D DD DD Land and Water Conservation Fund 614-265-6646 DD DDDDDD Clean Ohio Trails Fund 614-265-6477 D D Recreational Trails Program 614-265-6477 DD DDDDDD

Division of Forestry

Greenworks 614-265-6657 DD D D Recycle Ohio 614-265-6333 D

Division of Soil and Water Conservation

Local Soil and Water Conservation Agriculture Pollution Abatement Cost Sharing District Office DD Pollution Abatement Toolbox 614-265-6684 DD Non Point Source Pollution Grants 614-265-6682 D Conservation Reserve Enhancement Program (614) 255-2441 (CREP) DD Watershed Coordinators 614-265-6647 DD D Urban Streams Program 614-265-6685 DD DD D

Division of Wildlife

Grassland Restoration: Pastures to Prairies 614-265-6907 D D Wetland Restoration 614-265-6907 DD D

Ohio Department of Development

DoD website http://www.odod.state.oh.us/

Community Services Block Grant http://www.odod.state.oh.us/cdd/ocs/csbg.htm DDDDD

BIG DARBY ACCORD APPENDIX B — FUNDING SOURCES / 1 Resource Management Development Recreation Other Sites Trails Prevention Ordinances Maintenance Development Rehabilitation Streetscaping Improvements Wildlife Habitat Future Planning Future Restoration and Restoration Management and Management Facility and Service Facilities/ Amenities

Organization / Agency and Grant or Protection Farmland and Planning Future Land Acquisition/Open Land Acquisition/Open Conservation Corridors Conservation Pollution Control/ Water Water Control/ Pollution Rehabilitation of Existing Existing of Rehabilitation Education / Interpretation / Education Quality/Stormwater/Flood Quality/Stormwater/Flood Community and EconomicCommunity General Operating Budget Budget General Operating Space/Resource Protection Space/Resource

Program Website/Contact Restoration) (Rehabilitation/ Recreational Areas or Fields Recreational Neighborhood Revitilization / / Neighborhood Revitilization Office of Housing and Community Partnerships http://www.odod.state.oh.us/cdd/ohcp/ (grants and loans) DDDD DDDDD

Ohio Environmental Protection Agency http://www.epa.state.oh.us/cleanohio.html DDDDD Clean Ohio Fund http://www.epa.state.oh.us/cleanohio.html DDDDD Clean Ohio Green Space Conservation Program http://www.pwc.state.oh.us/clean_ohio.htm DD D DDDDD Clean Ohio Agricultural Easement Purchase http://www.ohioagriculture.gov/pubs/divs/farm/farm- Program index.stm DD Clean Ohio Trails Fund http://www.dnr.state.oh.us/cleanohiofund/admin.htm DDDDDD Clean Ohio Revitilization Fund http://www.odod.state.oh.us/ud/CORF.htm DDDD DD DDDDDD

Ohio Department of Transportation (Ohio http://www.dot.state.oh.us/programresource/ DOT) DD D DDDDD DDDD

Ohio Emergency Management Agency http://www.ema.ohio.gov/ema.asp (PEMA)

Ohio Water Development Authority http://www.owda.org/

http://www.owda.org/ProgramInfo/rdgrants/rdgrants. Research and Development Grant Program asp D D

Private Sources and Programs/Foundations

Altria Group, Inc. http://www.altria.com/responsibility/4_9_1_1_whatw efund.asp D http://mountainbike.about.com/od/bikenewsevents/a/ Balance Bar Bgrants_comm.htm http://www.kraft.com/profile/cares.html#Anchor- Kraft Food Focus-49575 Captain Planet Foundation http://www.captainplanetfdn.org/aboutUs.html D Cherokee Investment Partners http://www.cherokeefund.com DD DD Doris Duke Charitable Foundation http://www.ddcf.org/page.asp?pageId=1 DDDD D Local Initiatives Support Corporation (LISC) http://www.lisc.org D North American Association for http://eelink.net/pages/Grants+- Environmental Education +General+Information

The George Gund Foundation http://www.gundfdn.org/ DDDD D D http://www.joycefdn.org/seekingagrant/seekingmain- The Joyce Foundation fs.html D The John Merck Fund http://www.jmfund.org/ DDDD D Surdna Foundation http://www.surdna.org/ DDDD DD The Kenneth A. Scott Charitable Trust http://www.vetmed.wsu.edu/depts-pppp/Scott.asp D

The Columbus Foundation http://www.columbusfoundation.org

Clean Air Task Force http://www.catf.us/

The Energy Foundation http://www.ef.org/home.cfm

Kodak American Greenways Awards Program http://www.conservationfund.org D D D Environmental Support Center http://www.envsc.org/ D D

Great Lakes Aquatic Habitat Fund http://www.glhabitat.org/grants.html

Project Grants http://www.glhabitat.org/grant1.html DD

Technical Assistance Grants http://www.glhabitat.org/grant1.html

Special Opportunity Grants http://www.glhabitat.org/Special.html

Theme Grants http://www.glhabitat.org/grant2.html

Invasive Species Grants http://www.glhabitat.org/nuisance.html D

Great Lakes National Program Office of the http://www.epa.gov/glnpo/fund/glf.html National Fish and Wildlife Foundation

Institute for Conservation Leadership http://www.icl.org/

National Wildlife Federation http://www.nwf.org/

http://www.rivernetwork.org/library/index.cfm?doc_id River Network =114 DD State Environmental Leadership Program http://www.selp.org/ (SELP) DD

The Wege Foundation http://www.healingourwaters.org/

Rural Action http://www.ruralaction.org/

Smart Growth America (SGA) http://www.smartgrowthamerica.org D D

2 / APPENDIX B — FUNDING SOURCES BIG DARBY ACCORD Reference Information

American Journal of Agricultural Economics, 86 Georgia Stormwater Management Manual (Stormwater Quality (Number 5, 2004): 1196‐1202, American Agricultural Site Development Review Tool), August 2001. Economics Association, 2004. Hellbranch Watershed Forum, Inventory and Policy Papers, Arendt, Randall. Rural By Design, American Planning 2005 through 2006. Association, Chicago, IL, 1994. U.S. Green Building Council. Foundations of the Leadership in Bannerman, R. 1994. Sources of Pollutants in Wisconsin Energy and Environmental Design Environmental Rating System, Stormwater. Wisconsin Dept. of Natural Resources. A Tool for Market Transformation. LEED Policy Manual, Milwaukee, WI. January 2006.

Benedict, Mark and Edward T. McMahon. Renewable Metro Parks Community Update, 2004 Resource Journal, Green Infrastructure: Smart Conservation for the 21st Century, Autumn 2002. Miller, Economic Benefits of Open Space, 1992.

Center for Earth and Environmental Science, Indiana McQueen, Mike and Ed McMahon. Land Conservation University‐ Purdue University Financing. The Conservation Fund, Island Press, 2003.

(http://www.cees.iupui.edu/Education/floodplains.htm). Mid Ohio Regional Planning Commission 2030

Transportation Plan Summary (and Supplement), 2004 Central Ohio Transit Authority, Vision 2020 Transportation for a Great Community, Mid Ohio Regional Planning Mid Ohio Regional Fact Book, Regional Growth Strategy for Commission, 1999 Central Ohio. Mid Ohio Regional Planning Commission and

ACP ‐ Visioning and Planning, LTD. City of Columbus, Division of Sewerage and Drainage,

Stormwater Drainage Manual, March 2006. Minnesota Stormwater Steering Committee. The Minnesota

Stormwater Manual, Version 1.0, November 2005 Clark, J., et al. Growth and Change at the Urban Rural Interface,

An Overview of Ohio’s Changing Population and Land Use. Neitsch, S.L., et al. Soil and Water Assessment Tool: The Exurban Change Project Summary Report, The Ohio Input/Output File Documentation, Version 2005. State University, 2003. Blackland Research and Extension Center, Texas

Agricultural Experiment Station; Grassland, Soil and Water DiLuzio, M., et al. ArcView Interface for SWAT 2000: Research Laboratory, USDA Agricultural Research Service, User’s Guide. Blackland Research and Extension Center, September, 2004. Texas Agricultural Experiment Station; Grassland,

Soil and Water Research Laboratory, USDA Agricultural Neitsch, S.L., et al. Soil and Water Assessment Tool: Research Service, 2002. Theoretical Documentation, Version 2000. Blackland Research

and Extension Center, Texas Agricultural Experiment Duaney, Andres, William Wright, and Sandy Sorlien, Smart Station; Grassland, Soil and Water Research Laboratory, Code and Manual Version 8.0. New Urban Publications Inc. USDA Agricultural Research Service, 2002.

Federal Emergency Management Agency(FEMA). Northern Virginia Regional Planning Commission and Flood Insurance Study, Franklin County and Incorporated Areas, Engineers Surveyors Institute. Number 39049C. March 16, 2004. Northern Virginia Best Management Practices Handbook,

November 6, 1992. Federal Emergency Management Agency(FEMA). Flood

Insurance Rate Map, Franklin County and Incorporated Areas, Northern Virginia Planning District Commission, Division Number 39049C; panels 0115, 0116, 0205, 0210, 0215, 0220, of Environmental Services. Maintaining Your BMP, 0305 and 0310 G. August 2, 1995. February 2000.

Fuller, Mossbarger, Scott & May; Center for Watershed Ohio Department of Development, Ohio Office of Strategic Protection; Darby Creek Watershed Stormwater Management Research, Franklin County Population Projections by Age and Strategies and Standards for New Development, Volume 1; Sex: 2005‐2030. January 2001.

BIG DARBY ACCORD APPENDIX C — REFERENCE INFORMATION / 1 Ohio Department of Natural Resources. Fact Sheet 93‐18 – The President’s Council on Sustainable Development, The Hydrologic Cycle. Updated September 2, 1993 Towards a Sustainable America – Advancing Prosperity, Opportunity, and a Healthy Environment for the 21st Century, US. Ohio Department of Natural Resources. Geographic Government Printing Office, 1999. Information System (GIMS). Available URL:

“http://www.dnr.state.oh.us/gims/” US Army Engineer Research and Development Center, Ohio Department of Natural Resources, revised Rainwater Environmental Laboratory, Design Recommendations for and Land Development Manual (Draft), May 2005 Riparian Corridors and Vegetated Buffer Strips, April 2000.

Ohio Department of Natural Resources. Report No. 40 ‐ USDA‐SCS. United States Department of Agriculture‐ Ground Water Pollution Potential of Franklin County. Natural Resources Conservation Service. 2004. Soil Survey of Michael P. Angle. 1995 Franklin County, Ohio.

Ohio EPA and City of Columbus Public Utilities. USDA‐SCS. 1985. Hydric Soils of the United States. Environmentally Sensitive Development Area, External Advisory USDA‐SCS National Bulletin No. 430‐5‐9. Washington, D.C. Group Recommendations, November 2004. US EPA. Office of Wetlands, Oceans and Watershed. Ohio EPA. NPDES Permit NO. OHC100001. Fact Sheet and National Management Measure to Control Non‐point Source Draft Permit. December 2005. Pollution from Urban Areas, Draft July 2002,

Ohio EPA. Division of Surface Water. Biological and Water U.S. Geological Survey. Floodprone Quadrangles. 1978. Quality Study of the Big Darby Creek Watershed, 2001/2002, June 28, 2004. Webb, Ben. Darby Creek Watershed Inventory (Final Draft). Produced in partnership with the Darby Creek Watershed Ohio EPA. Division of Surface Water. Darby at the Crossroads. Joint Board of Supervisors and the Darby Creek Watershed June 30, 2004. Planning Group. March 21, 2005.

Ohio EPA. Division of Surface Water. State Water Quality Williams, Lance R., Ph. D. and Marsha G. Williams, M.S. Management Plan, Final Draft, February 2006. Evaluation of Stream and Riparian Enhancement Opportunities for the Hellbranch Watershed in Central Ohio. School of Ohio EPA. Division of Surface Water. Total Maximum Daily Natural Resources, The Ohio State University. January 16, Loads for the Big Darby Creek Watershed, Final Report, 2004, revised March 12, 2004. January 6, 2006. US Census Bureau, Summary Table 1 Population, Rhoads, Bruce L., David Wilson, Michael Urban, Edwin E. 1990 and 2000. Herricks. Interaction Between Scientists and Nonscientists in Community‐Based Watershed Management: Emergence of the Prairie Township Comprehensive Plan, 2003 Concept of Stream Naturalization, 1999. Brown Township Comprehensive Plan, 2005 Franklin County Zoning Resolution, March 2004 Schueler, T.R. The Importance of Imperviousness, Watershed Hilliard Economic Development Master Plan Protection Techniques 1 (3): 100‐111. 1994. City of Hilliard Thoroughfare Plan, 2001 Pleasant Township Comprehensive Plan Sohngen, Brent. An Investigation to the Potential to Link Franklin County Greenways Plan Voluntary Incentives Payments to Water Quality Performance. Columbus Comprehensive Plan, 1993 Ohio State University Department of Agriculture, Environment and Development Economics, March 2005. (In The Darby Accord recognizes the following organizations association with Taylor, Department of Political Science, for contributing photos for the Big Darby Accord Plan: Seton Hall University). The Darby Creek Association The Nature Conservancy Soil Survey Staff, Natural Resources Conservation Service, Metro Parks United States Department of Agriculture. Soil Survey Geographic (SSURGO) Database for Survey Area, State [Online WWW]. Available URL: ʺhttp://soildatamart.nrcs.usda.govʺ [Accessed 5/18/05].

Steur, stormwater center.net, better site design fact sheets

2 / APPENDIX C — REFERENCE INFORMATION BIG DARBY ACCORD Inventory of GIS Data for Darby Creek Watershed

Category Data Layer Spatial Extent Data Type Feature Type Date of Data Source Material Aerial photography Orthophotos (b/w) Western part of .sid image N/A 2000 Franklin County Auditor Franklin County USGS Orthophotos (color) Darby watershed GeoTIFF N/A May 2002 USGS website

Base Map Address ranges Franklin County shapefile Line 2005 Franklin County Auditor

Addresses of parcel owners Franklin County shapefile Point 2005 Franklin County Auditor

Buildings (only roofed structures) Franklin County shapefile Line 2005 Franklin County Auditor

Parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Airport parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Cemetery parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Condo parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Golf course parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Health services parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Hopsital parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Misc. parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Notable building parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Parks and recreation center parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Police and fire departments parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Service-related parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Retirement center parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

School parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Shopping center parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Subdivision parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Tall building parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Venue parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Worship center parcels Franklin County shapefile Polygon 2005 Franklin County Auditor

Railroads Franklin County shapefile Line 2005 Franklin County Auditor

Road centerlines Franklin County shapefile Line 2005 Franklin County Auditor

Roads Franklin County shapefile Line 2005 Franklin County Auditor

School districts Franklin County shapefile Polygon 2005 Franklin County Auditor

Structures (all man-made Franklin County shapefile Line 2005 Franklin County Auditor feaures/structures as seen in orthophotos) Subdivisions (points) Franklin County shapefile Point 2005 Franklin County Auditor

Tax districts Franklin County shapefile Polygon 2005 Franklin County Auditor

Zipcodes Franklin County shapefile Polygon 2005 Franklin County Auditor

BIG DARBY ACCORD APPENDIX C — INVENTORY OF GIS DATA / 1 Inventory of GIS Data for Darby Creek Watershed

Category Data Layer Spatial Extent Data Type Feature Type Date of Data Source Material Bikeways MORPC shapefile Line Unknown MORPC

Parks, Golf Courses, Cemeteries MORPC shapefile Polygon Unknown MORPC

School districts MORPC shapefile Polygon Unknown MORPC

ODOT Road centerlines - interstates, Ohio shapefile Line 2004 ODOT US highways, state routes ODOT Road centerlines - county & Ohio shapefile Line 2004 ODOT township roads ODOT Road centerlines - municipal Ohio shapefile Line 2004 ODOT roads City of Columbus parks City of Columbus shapefile Polygon Unknown City of Columbus, Parks & Recreation City of Columbus recreation centers City of Columbus shapefile Point Unknown City of Columbus, Parks & Recreation City of Columbus senior centers City of Columbus shapefile Point Unknown City of Columbus, Parks & Recreation City of Columbus hospitals City of Columbus shapefile Point 2005 City of Columbus

City of Columbus neighborhood health City of Columbus shapefile Point 2005 City of Columbus centers City of Columbus urgent care centers City of Columbus shapefile Point 2005 City of Columbus

City of Columbus police stations City of Columbus shapefile Point 2005 City of Columbus

City of Columbus fire stations City of Columbus shapefile Point 2005 City of Columbus

Parcels (DUPLICATE DATA) Townships within shapefile Polygon Unknown Franklin County Franklin County Cultural Resources National Register sites Study area shapefile Point 2005 Ohio Historical Preservation Office (OHPO)

Ohio Archaeological Inventory (OAI) Study area shapefile Point 2005 Ohio Historical Preservation sites Office (OHPO)

Ohio Historical Inventory (OHI) sites Study area shapefile Point 2005 Ohio Historical Preservation Office (OHPO)

Previously Surveyed Areas (PSA) Study area shapefile Polygon 2005 Ohio Historical Preservation Office (OHPO)

Demographics Population change - 1990 to 2000 Darby watershed shapefile Polygon 2000 Benjamin Webb, Darby Creek Watershed Coordinator US Census 2000 Data Franklin (39049), shapefiles, Polygon 2000 ESRI Geography Network Madison (39097), tables and Pickaway (39129) Counties

Environmental Resources Agency & non-profit preserved land Darby watershed shapefile Polygon 2004 ODNR, Division of Natural Areas and Preserves Franklin County easements Franklin County shapefile Polygon Unknown MORPC

Environmental Conservation District N/A shapefile Polygon Unknown MORPC (ECD) grid Environmentally Sensitive N/A shapefile Polygon Unknown OEPA Development Area (ESDA) boundary Environmentally Sensitive N/A shapefile Polygon Unknown City of Columbus Development Area (ESDA) boundary Environmentally Sensitive N/A shapefile Polygon Unknown MORPC Development Area (ESDA) grid Historic vegetation Darby watershed .jpg image N/A Unknown ODNR

2 / APPENDIX C — INVENTORY OF GIS DATA BIG DARBY ACCORD Inventory of GIS Data for Darby Creek Watershed

Category Data Layer Spatial Extent Data Type Feature Type Date of Data Source Material Biological Water Quality Indices - Darby watershed shapefile Point 2004 Benjamin Webb, Darby Bugs Creek Watershed Coordinator (created using OEPA Sampling Data, 1977- 2002) Biological Water Quality Indices - Fish Darby watershed shapefile Point 2004 Benjamin Webb, Darby Creek Watershed Coordinator (created using OEPA Sampling Data, 1979- 2003) Biological Water Quality Indices - Darby watershed shapefile Point 2004 Benjamin Webb, Darby Sampling Trends Creek Watershed Coordinator (created using OEPA Sampling Data, 1979- 2003) Water quality attainment, Aquatic life Darby watershed shapefile Line 2004 Benjamin Webb, Darby use designations Creek Watershed Coordinator (created using OEPA Sampling Data, 2001- 2002) Public water supplies Franklin County shapefile Point 2004 OEPA portion of Darby National Wetland Inventory (NWI) Studythd area scanned N/A 1985 US Fish & Wildlife Service images (.tif) Ohio Wetland Inventory (OWI) Franklin County shapefile Polygon 1987 ODNR website

NPDES Point Sources Darby watershed shapefile Point 2004 OEPA

Riparian cover Darby watershed shapefile Line 2004 Benjamin Webb, Darby Creek Watershed Coordinator Natural Heritage Database Study area shapefile Polygon 2005 ODNR, Division of Natural Areas and Preserves Managed Areas Study area shapefile Polygon 2005 ODNR, Division of Natural Areas and Preserves Scenic Rivers Study area shapefile Line 2005 ODNR, Division of Natural Areas and Preserves Metro Parks land holdings Western part of shapefiles Polygon, Line 2005 Metro Parks Franklin County (derived from AutoCAD) Floodplains FEMA 100-yr boundary Franklin County shapefile Polygon 1978 ODNR website

FEMA floodway Franklin County shapefile Polygon 1978 ODNR website

FEMA other flood hazard areas Franklin County shapefile Polygon 1978 ODNR website

Flooding potential (USGS & NRCS) Franklin County shapefile Polygon 1978-79 ODNR website

Inventory of structures at risk of Franklin County shapefile Point 1995 ODNR website flooding USGS flood prone areas Franklin County shapefile Polygon 1978 ODNR website

Geology Bedrock geology Franklin County shapefile Polygon 1958 ODNR website

Depth to bedrock Franklin County shapefile Polygon 1979 ODNR website

Glacial geology Franklin County shapefile Polygon 1958 ODNR website

Ground water pollution potential Franklin County shapefile Polygon 1995 ODNR website

Ground water resources Franklin County shapefile Polygon 1993 ODNR website

Limitations for large scale Franklin County shapefile Polygon 1958-79 ODNR website development Oil and gas well location database Franklin County .dbf N/A 2004-05 ODNR website

BIG DARBY ACCORD APPENDIX C — INVENTORY OF GIS DATA / 3 Inventory of GIS Data for Darby Creek Watershed

Category Data Layer Spatial Extent Data Type Feature Type Date of Data Source Material Hydrography Lakes Ohio shapefile Polygon Unknown ODOT

Rivers Ohio shapefile Line Unknown ODOT

Lakes, rivers, streams Franklin County shapefile Line 2005 Franklin County Auditor

National Hydrography Dataset (NHD) Scioto River GDB N/A 2005 USGS NHD website watershed USGS Digital Line Graphs (DLGs) Franklin County shapefile N/A (as per USGS USGS topo maps) Land Use 1976 Land Use/Land Cover Franklin County shapefile Polygon 1976 ODNR website

1992 National Land Cover Dataset Darby watershed grid N/A 1992 USGS NLCD website (NLCD) - USGS 1994 Land Cover Franklin County shapefile Polygon 1994 ODNR website

1998 Land Use/Land Cover Franklin County shapefile Polygon 1998 ODNR website

2005 Existing Land Use (auditor's Franklin County shapefile Polygon 2005 Franklin County Auditor parcel data) Hybrid Land Use Data Darby watershed ARC/INFO N/A Various Benjamin Webb, Darby Coverage, Creek Watershed Raster (with Coordinator corresponding layer file) Existing and Future land use Franklin County shapefile Polygon Unknown MORPC

Existing and Future land use Madison County shapefile Polygon Unknown MORPC

Existing land use Pickaway County shapefile Polygon Unknown MORPC

Future land use Pickaway County shapefile Polygon Unknown MORPC

Existing and Future land use Union County shapefile Polygon Unknown MORPC

Prime farmland Franklin County shapefile Polygon 1979 ODNR website

Development - Commercial (through Franklin & shapefile Point 2005 MORPC May 2005) Delaware Counties Development - Residential (through Franklin & shapefile Point 2005 MORPC May 2005) Delaware Counties Planning Data Airport noise levels City of Columbus shapefile Polygon 2005 City of Columbus

Hellbranch planning overlay City of Columbus shapefile Polygon 2005 City of Columbus

Hellbranch planning overlay City of Columbus shapefile Polygon 2005 City of Columbus (DUPLICATE DATA) Northwest corridor boundary City of Columbus shapefile Polygon 2005 City of Columbus

Westland area plan - adopted 1994 City of Columbus shapefile Polygon 2005 City of Columbus

West Columbus Interim Development City of Columbus shapefile Polygon 2005 City of Columbus Concept - adopted 1991 Political Boundaries City boundaries Franklin County shapefile Polygon 2005 Franklin County Auditor

Township boundaries Franklin County shapefile Polygon 2005 Franklin County Auditor

Corporate Boundaries Franklin County shapefile Polygon Unknown Franklin County

County boundaries Ohio shapefile Polygon Unknown ODOT

Historical township boundaries Franklin County shapefile Polygon 2005 Franklin County Auditor

4 / APPENDIX C — INVENTORY OF GIS DATA BIG DARBY ACCORD Inventory of GIS Data for Darby Creek Watershed

Category Data Layer Spatial Extent Data Type Feature Type Date of Data Source Material Neighborhood boundaries Franklin County shapefile Polygon 2005 Franklin County Auditor

Soils Data SSURGO Franklin County shapefile Polygon 1980 NRCS website

Hydric soils Study area shapefile Polygon 1980 EMHT created from SSURGO data Topography 2-ft contours - Franklin County Study area shapefile Line 2005 Franklin County Auditor

5-ft contours - Madison County Madison County shapefile Line Unknown Madison County GIS website

National Elevation Dataset (NED) Darby watershed grid N/A Created USGS website 1-arc second resolution 1999 National Elevation Dataset (NED) Western part of grid N/A Created Oct USGS website 1/3-arc second resolution Franklin County 2003 Spot elevations Franklin County shapefile Point 2005 Franklin County Auditor

Transportation Franklin County 2020 Thoroughfare Franklin & shapefile Line 2005 MORPC Plan - Draft Delaware Counties + City of Columbus Thoroughfare Plan City of Columbus shapefile Line 2005 City of Columbus

Transportation Improvement Plan Franklin & shapefiles Various Unknown MORPC (TIP), FY 2006-2009 (July 1, 2005 to Delaware Counties June 30, 2009) + Transportation Plan - 2030 (TPLAN) Franklin & shapefiles Various Unknown MORPC Delaware Counties + ODOT Road centerlines - interstates, Ohio shapefile Line 2004 ODOT US highways, state routes (contains some ADT data) Traffic Analysis Zones (TAZ) with Franklin County + shapefile Polygon 2000 MORPC incremental 30-yr forecast data Utilities Sewer service areas Darby watershed shapefile Polygon 2004 Benjamin Webb, Darby Creek Watershed Coordinator Proposed Facility Planning Area N/A shapefile Polygon Unknown MORPC (FPA) for City of Columbus Community Planning Areas Franklin County + shapefile Polygon Unknown City of Columbus

Marysville existing sewer area N/A shapefile Polygon Unknown MORPC

Pickaway future sewer area N/A shapefile Polygon Unknown MORPC

Union sewer service area N/A shapefile Polygon Unknown MORPC

Water and Wastewater Treatment MORPC shapefile Point Unknown MORPC Plants - DATA INCORRECT City of Columbus Sewer Lines Study area shapefile Line Unknown City of Columbus (DOSD) City of Columbus Sewer Nodes Study area shapefile Point Unknown City of Columbus (DOSD) City of Columbus utility data (SECAP City of Columbus shapefiles Line 2005 EMHT project) - sewer lines (sanitary, storm, combined) SECAP - sanitary sewers (including City of Columbus shapefile Line 2005 EMHT combined) 18" and larger SECAP - sanitary sewers (including City of Columbus shapefile Line 2005 EMHT combined) main trunk lines only SECAP - service boundary area City of Columbus shapefile Polygon 2005 EMHT

SECAP - sewersheds City of Columbus shapefile Polygon 2005 EMHT

SECAP - pump stations City of Columbus shapefile Point 2005 EMHT

BIG DARBY ACCORD APPENDIX C — INVENTORY OF GIS DATA / 5 Inventory of GIS Data for Darby Creek Watershed

Category Data Layer Spatial Extent Data Type Feature Type Date of Data Source Material SECAP - contract entities City of Columbus shapefile Polygon 2005 EMHT

City of Hilliard water lines City of Hilliard shapefile Line 2005 City of Hilliard

City of Hilliard sanitary sewer lines City of Hilliard shapefile Line 2005 City of Hilliard

City of Hilliard storm sewer lines City of Hilliard shapefile Line 2005 City of Hilliard

Watersheds 8-digit watersheds, USGS Ohio shapefile Polygon 1996 Created from Detailed Ohio watersheds file 11-digit watersheds, NRCS Ohio shapefile Polygon 2005 Ohio NRCS website

14-digit watersheds, NRCS Ohio shapefile Polygon 2005 Ohio NRCS website

Detailed Ohio watersheds, USGS Ohio shapefile Polygon 1996 ODNR website

Darby Creek watershed Darby watershed shapefile Polygon 1997-99 Created by Ben Webb using NRCS 14-digit watersheds

Darby Creek watershed (DUPLICATE Darby watershed shapefile Polygon 1997-99? Unknown - created using DATA) NRCS 14-digit watersheds Darby Creek watershed, with 14-digit Darby watershed shapefile Polygon 1997-99? Unknown - created using subwatersheds NRCS 14-digit watersheds Zoning Township zoning map Townships within shapefile Polygon 2005 Franklin County Franklin County Prairie Township zoning map Prairie Twp shapefile Polygon 2005 Franklin County

Washington Township zoning map Washington Twp shapefile Polygon 2005 Franklin County

City of Columbus zoning map City of Columbus shapefile Polygon 2005 City of Columbus

City of Hilliard zoning map City of Hilliard shapefile Polygon 2005 City of Hilliard

6 / APPENDIX C — INVENTORY OF GIS DATA BIG DARBY ACCORD Big Darby Accord Advisory Panel Development Review Checklist - Concept

Project Information

Public Public Sq Ft or Number Proposed Permitted Open Space Location (Requested) Zoning Use(s) Acreage Parkland Parkland of Units Density Density Required Provided Required

Water Quality / Conservation yes no Details / Comments Incorporates BMPs in Site Plan to achieve TMDL Requirements Protects Tier 1 Land Protects Tier 2 Land Protects Tier 3 Land Protects Stream Corridor Protection Zone Incorporates Stream Restoration Incorporates Site Monitoring of Water Quality Incorporates Low Impact Development Techniques Provides Open Space that Links with Adjacent Open Space Areas Incorportes Permanent Easements to Protect Open Space Land Meets and Complies with all Ohio EPA Requirements Meets Sewage System requirements Provides Necessary Performance Bond for Monitoring and Open Space Areas Provides Necessary Measures for Site-level Monitoring Development yes no Details / Comments Incorporates Principles of Conservation Development Incorporates Principles of Town Center Development Incorporates Principles of LEED ND Land use is Consisitent with Darby Accord Plan Proposed Density is Consistent with Darby Accord Plan Incorporates Required Public Facilities Provides Trail Linkages Provides Revenue Toward achieving the Darby Accord Plan Provides Required Transportation Improvements

BIG DARBY ACCORD APPENDIX D — DEVELOPMENT REVIEW CHECKLIST / 1 THIS PAGE LEFT INTENTIONALLY BLANK Stormwater Utility

A stormwater utility is a special infrastructure, using the revenues The first step in creating a assessment set up to generate generated by the utility to pay back stormwater utility is the evaluation funding specifically for stormwater those bonds. of the number of equivalent management. Users within the residential units and the delineation utility pay a stormwater fee and the Establishing the of the impervious area. A revenue generated from the fee is Utility Fee Structure comprehensive rate study may be used to support maintenance and The utility fee is related to the completed to determine the upgrades to the existing storm amount of runoff that a parcel of revenue needs to support the drain system, the development of land contributes to the overall community’s stormwater programs drainage plans, water quality stormwater condition. The fee and initiatives and justify the programs, and to cover structure includes an option for amount of the utility fee assessed administrative costs. Communities credits through stormwater on an ERU basis. The study should in Ohio are increasingly examining quantity reduction or water quality account for costs related to the the option of stormwater utilities improvement, providing an items listed below. for use in funding stormwater incentive for developers of management and water quality commercial (and industrial) x Operation and maintenance of programs in order to keep up with properties to consider methods for stormwater infrastructure, including the requirements of the NPDES reducing pervious area. personnel and equipment costs. Phase II program. The shift towards x Development and promulgation of stormwater utility funding Most stormwater utilities base the stormwater programs, including addresses the need for a consistent user fees at least in part on the ordinances, policies and regulations, source of revenue. The Accord percentage of impervious cover of and initiatives related to public should consider a stormwater the parcels of developed land outreach and education. utility as another funding option within the community. For x Compilation of technical for implementing the Plan. simplicity, many utilities charge a documentation related to the public flat rate for residential properties stormwater infrastructure, including Stormwater utilities are often a and then assess commercial and mapping and capacity analysis preferred funding method due to industrial properties based upon (where appropriate). limited resources available to cities the actual impervious area within x Development and implementation of and counties to meet the general their parcel. The stormwater fee is a Capital Improvement Program government needs related to frequently included as a line item (CIP) to replace or upgrade implementation of the NPDES within the water and sewer bill. components of the stormwater Phase II program. The utility infrastructure. generates additional funds directly The revenue that could be targeted to address the increasing generated by a stormwater utility Once the stormwater utility rate is requirements of stormwater would be dependant upon the established, the community must management programs. The number of parcels and the prepare an ordinance that will revenues generated by the utility stormwater rate fee. Residential adopt the utility, establish its rules are constant, gradually increasing users are typically charged a base and regulations and also stipulate with the community’s growth and rate per equivalent residential unit the system of rates and charges. It is rate structure. The constant income (ERU), representing an “average” important to note that even with a directed toward the stormwater amount of imperviousness for a user fee system in place the cost of program allows for programmatic residential lot. This base fee a comprehensive stormwater stability, supports the stormwater typically ranges from $2 to $5 per program, especially related to large staff, and provides for continued month, per ERU. Non‐residential capital projects, will often exceed maintenance and monitoring users are typically charged per the revenues that a utility can operations. Bonds for capital square footage of impervious area. generate. A utility is part of the improvements can also be issued to A rate of 2.5 ERU per commercial revenue stream but it is not all of it. facilitate construction of parcel is an average that can be stormwater management used for revenue approximation.

BIG DARBY ACCORD APPENDIX E — STORMWATER UTILITY / 1 Application to the Accord Planning Area The City of Columbus already has an established stormwater utility program that funds a comprehensive program related to maintenance of and improvements to their public stormwater infrastructure. The City of Hilliard has considered implementing a similar program. Within the remainder of the Accord planning area, a stormwater utility could be established and implemented by the Franklin County Drainage Engineer. The authority for such a program outside of an incorporated community is provided within the Ohio Revised Code, Chapter 6117. This utility would then be administered through the office of the County Drainage Engineer or other governmental body, such as the Franklin County Soil and Water Conservation District.

The mechanism for billing the stormwater utility within the unincorporated areas may have to be examined in consideration of the fact that there would not be a consistent system of sanitary and/or water utility billing throughout the county.

2 / APPENDIX E — STORMWATER UTILITY BIG DARBY ACCORD Darby Alternative Wastewater Treatment Technical Advisory Committee

Date: Friday, June 23, 2006

Committee Members: Paul Rosile, FCBH Timothy Lawrence, Ohio NEMO (Chair) Karen Mancl, OSU Extension Gary Young, FCBH Tom Shockley, FCSE Mike Gallaway, OEPA Ex-Officio: Cathy Alexander, OEPA Dave Parkinson, EMH&T Jean Caudill, ODH Kevin Kershner, Zande & Associates Mike Rowan, OSU FABE

Draft Recommendations:

This committee was formed independent of the Darby Accord to provide guidance and recommendations for landowners and jurisdictions within Franklin County portion of the Darby regarding their options for wastewater treatment. The Franklin County portion of the Darby Watershed is likely to experience major development within the next 20 to 30 years as outlined in the Darby Accord Plan (DAP), developed by the 10 political jurisdictions involved. Currently there are approximately 12,500 units in the area, the majority being on non-centralized sewer. The DAP calls for that number to grow to 32,500 units, with approximately 7,000 of the new units on centralized sewer. This leaves approximately 13,000 new units, within the Accord planning area needing to find onsite or an acceptable regional approach to wastewater treatment. The Ohio Legislature has recently enacted new legislation for household sewage treatment systems (HSTS). Scheduled to go into effect January 1st, 2007. These new regulations were crafted to assure the highest level of wastewater treatment and the protection of public health and environmental quality from individual households and other similar and ancillary uses. The regulationsDraft also require local boards of health to establish nutrient reduction standards in areas “when there is a significant risk of nutrient contamination to surface or ground water…or risk due to proximity to local, state, or federally recognized nutrient sensitive environments.” Residents and jurisdictions are encouraged to review those regulations and consult with the Franklin County Board of Health for restrictions that apply to property within this area.

The committee’s recommendations, presented in this document, are limited to land application (drip, spray, or other timed and pressure dosed effluent distribution) systems for household (one home connected to its own system), and community (a group of homes on one treatment system, but not connected to the main sewer trunk from Columbus, i.e., centralized sewer). The use of community type systems supports the application of “conservation” developments, or developments with significant open space. The committee recognizes that household sewage treatment systems, such as the Wisconsin mound system and a drip distribution system (possibly with nutrient reduction components) may be necessary to overcome specific site conditions and to meet new

BIG DARBY ACCORD APPENDIX F — ALTERNATIVE WASTEWATER TREATMENT / 1 state regulations. This document contains general concerns, limitations, and recommendations to protect human health and the biological and ecological integrity of the Darby Creek system.

The two areas targeted for non-centralized sewer in the DAP are Brown and Pleasant Township. There is also a smaller area within Prairie Township that may have some units not on centralized sewer. The single biggest limiting factor to non-centralized alternative wastewater treatment in this area is the soil types. Brown Township is predominately a Kokomo-Crosby-Lewisburg (KCL) soil association that is great for farming but has conditions that limit the use of household sewage treatment systems such as leach fields, Wisconsin mounds, or other land application systems. Pleasant Township also has a large percentage of KCL soil association. However, they also have some areas of Miamian and Celina intermixed with Lewisburg and Crosby, all of which may support HSTS. The committee stressed the importance of site specificity and cautioned about making blanket statements regarding Crosby or Lewisburg in regard to their suitability for household sewage treatment systems. There is consensus among the members of the committee that HSTS should continue to not be permitted on Kokomo soils. Kokomo soils are not permitted for HSTS for new development in any part of Franklin County.

Another important limiting factor is the depth to the seasonally high water table or other limiting conditions. The KCL soil association is seasonally saturated with a water table that will need to be professionally evaluated on each site being considered for development. In addition to the depth to seasonal water table, the type of water table – apparent or perched – is also an area of concern. An apparent water table is connected with the ground water system. The new state rules places additional restrictions on the use of apparent seasonal high water tables for HSTS. Perched water tables may have fewer restrictions, but still have significant limitations. Thus the committee recommends that HSTS only be permitted in areas where the perched water table is at least 12 inches below the surface where the treated effluent is being applied. This recommendation would ensure a strict application of the new sewage rules with no variances to accommodate moreDraft severe soil limitations, and no gradient drainage around the HSTS to remove excess groundwater from around the system.

Seasonal application of drip or spray community (see above definition) land application systems on Kokomo is an option that the committee does support. However, this would require the onsite storage of large amounts of wastewater during times when the soil is saturated (generally the winter months but can begin in the fall and extend well into the spring). Other soil types found in the area are also suitable for land application systems, but they too are limited during saturated conditions. Land application should not be made strictly by the calendar and the operator of any system should carefully monitor the soil water conditions to ensure there is at least 12 inches of soil above the water table before making application.

The placement of any community land application system must first contain a component of a documented investigation into the tiling structure on the proposed spray field. If a tile does exist in the spray field, then efforts to collect and divert the tile away from the

2 / APPENDIX F — ALTERNATIVE WASTEWATER TREATMENT BIG DARBY ACCORD spray field must be done. This effort will include interception of the tile before it reaches the spray field, collection of all subterranean streams prior to the proposed spray field, and diversion into a new tile or existing tiling system which must show evidence of the continuum of the streams downstream. The committee recommends adherence to the Franklin County Sanitary Engineer’s "Rules and Regulations for the Construction & Operation of Land Application Wastewater Treatment Systems,” for spray field placement which is referenced under "Hydrogeologic Site Investigation/Soils Report of the Application Site." The hydrogolgic site investigation/soils report includes the location of the tiles and the feasibility of rerouting the drainage system from the spray field. This report should be presented to both the Franklin County Sanitary and Drainage Engineer for approval.

The committee recommends that the multi-unit community or “cluster development” permitted in the DAP which is not on a centralized sewer system be serviced by either a regional (more than one small community) or one community system for each group of homes, be managed under the direct supervision and maintenance of the Franklin County Sanitary Engineer. Where feasible, regional treatment systems are strongly encouraged. However, the committee also recognizes that there may be developments where it is cost prohibitive to run sewer lines to a regional facility. The committee supports the idea of using sewage treatment technology other than the traditional aeration treatment plant for community systems prior to land application, such as fixed film bio-reactors (re- circulating sand filters and synthetic or peat filter systems) however, these systems should also be under the direct supervision and maintenance of the Franklin County Sanitary Engineer. The committee is also aware that properties with existing HSTS will be in close proximity to new regional or community developments; therefore it will be necessary to connect all of those properties that are contiguous (i.e., accessible/available) into the community or regional treatment system.

The committee supports the Ohio EPA Draft Rules for Land Application of Treated Sewage dated Oct 2003 monitoring frequency requirements. In addition it is recommended thatDraft monitoring wells in all land application fields be installed to ensure the depth to water table is at least 12 inches before effluent is applied. The committee also supports the requirement for obtaining an NPDES permit on any system that discharges directly into the Darby or any of it tributaries regardless of their size. There was also support for Land Application Management Plans for any system that is a non- discharging and the requirement for a five year renewal of those plans. The committee made these recommendations prior to the release of a more current version of the draft rules that will eventually be adopted by the state of Ohio after comment and further review. Thus the recommendations put forth in this document may change to reflect these new rules, which will set the standard for governance.

When there is less than 12 inches of unsaturated soil above the water table the treated effluent should be diverted to a holding pond which has a minimum storage capacity of 6 months based on 300 gal/unit/day. These ponds are for storage only and should not be a part of the treatment process, however the committee does not object to the use of aeration if deemed appropriate by the operator to minimize algae growth. These ponds

BIG DARBY ACCORD APPENDIX F — ALTERNATIVE WASTEWATER TREATMENT / 3 should not be placed within the “streamway” as defined in the DAP or within the 100- year flood plain, however, they should be permitted within designated open space areas. Similar restrictions should also apply to aeration treatment plants or bio-reactor systems.

In all areas under consideration, with exception to the spray fields outline above, the existing field tile system should be maintained to ensure adequate drainage of the water table from areas that have or may have a HSTS, single community or regional wastewater treatment system. It is suggested that these existing field tile systems be placed under the ditch petition process or other maintenance assessment programs through Franklin County.

These recommends are intended for the protection of both human health and the Darby ecological system from pathogens and pollutants. The committee recognizes that it will need to continue to meet with regulators and other interested parties to further refine and implement a final set of recommendations. Draft

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