Types, Applications, and Design Approaches to Manage Wet Weather

Green Roofs

Green Roofs for Stormwater Runoff Control (81 pp, 2.75MB) - This EPA report evaluates green roofs as a stormwater management tool; runoff quantity and quality from green and flat asphalt roofs were compared. Evapotranspiration from planted green roofs and evaporation from unplanted media roofs were also compared. The influence of media type, media depth and drought during plant establishment on plant growth and long-term management of media pH were investigated. The goal of the project was to provide high-quality replicated data which could be used to develop and refine reliable anticipated runoff volumes and loadings from green roofs, respectively, as well as evaluate factors which impact plant growth and establishment. Results indicate that the green roofs are capable of removing 50% of the annual rainfall volume from a roof through retention and evapotranspiration.

Green Roofs as Urban Ecosystems: Ecological Structures, Functions, and Services - Provides a general overview of green roof design and function while also discussing the multiple benefits these roof systems can provide.

Green Roofs for Healthy Cities - Collects and publishes technical information on green roof products and services.

Seattle Green Roof Evaluation Project: Final Report (PDF) (6 pp, 1.7MB) - Magnusson Klemencic Associates (MKA), a structural engineering firm, led a $125,000 two-year vegetated roof evaluation project in Seattle and found that a green roof has the potential to lower stormwater runoff from 65-94%. Note: MKA developed an event-based model to simulate the hydrologic response of the green roof, instead of a continuous model. Third party review of the project reports that the detection limit of the SGREP test plots was approximately 0.10 iph; therefore, these data did not capture small precipitation and runoff values, and are better applied for peak flows.

Stormwater Monitoring on Two Ecoroofs in Portland, Oregon, USA - In this report, the Portland Bureau of Environmental Services initiated a monitoring project of an apartment building vegetated with two different ecoroofs. After over two years of water quality monitoring and over a year of flow monitoring, some impressive performance has been measured. Precipitation retention has been calculated at 69% for the 4-5 inch ecoroof substrate section and nearly all of the rainfall is absorbed during dry period storm events.

Rain Harvesting

Municipal Handbook: Rain Harvesting (PDF) (16 pp, 1.44MB) - This chapter of EPA's Municipal Handbook addresses harvesting principles, designs, example code requirements, and policies and incentives of implementing a municipal rainwater harvesting program. Rainwater harvesting can reduce stormwater runoff, conserve potable water, and provide environmental and economic benefits. Barriers to implementation are also addressed, and case studies from across the country demonstrate successful rainwater harvesting programs.

Texas A & M University's Rainwater Harvesting - This university website provides information on fundamental rain water harvesting techniques, including discussion on suggested uses of harvested rain water. Pictures and descriptions of existing rain water harvesting projects in Texas are also found on this site.

Water Harvesting at NC State University - Outlines the benefits of water harvesting and has a "how-to" guide on installing a simple rain harvesting system. Also includes a downloadable Rainwater Harvester computer model to aid in determining the appropriate cistern size for a given structure.

Downspout Disconnection

City of Chicago - Disconnect Your Downspout - Promotes downspout disconnection as one technique to help alleviate flooding and provides basic principles and illustrations for homeowners on how to disconnect their downspouts.

Mid-America Regional Council - Provides a general overview of downspout disconnection benefits while also discussing the steps to disconnect a downspout.

Toronto Homeowners' Guide to Rainfall: Downspout Disconnection - Explains benefits associated with downspout disconnection and provide tips and instructions on how to properly disconnect home downspouts.

D.C. Greenworks: Downspout Disconnection - D.C. Greenworks promotes green infrastructure and green roofs, along with downspout disconnection; also includes roof runoff calculator to determine volume of captured water.

Planter Boxes

Charles River Watershed Association Fact Sheet on Stormwater Planters (PDF) (2 pp, 1.13MB) - This fact sheet provides an overview of the various types of stormwater planters, including design schematics, cost, and maintenance.

New York State Stormwater Management Design Manual (PDF) (7 pp, 280K) - This excerpt from the redevelopment chapter provides information on three versions of stormwater planters: contained planters, infiltration planters, and flow-through planters. It includes sizing and design guidance.

City of Portland, Planter Boxes - Contains information on container, infiltration, and flo-through planters, complete with pictures of each kind.

Rain Gardens

LID Center Rain Garden Design Templates - This site has been developed through a National Fish and Wildlife Foundation grant to display a series of rain garden design templates, to be used by landscape architects and contractors, and garden clubs throughout the Chesapeake Bay region. These designs promote the use of rain gardens and Bayscapes by providing accessible, high quality, sustainable and easily maintained designs for industry and citizens.

Rain Gardens: A How-To Manual for Homeowners (PDF) (32 pp, 4.96MB) - The Wisconsin Department of Natural Resources published this colorful guide for rain garden siting and design in 2003. Provides answers to frequently asked questions, sizing, siting, building, planting, and maintaining a rain garden. The manual includes diagrams and suggested plant materials for building a rain garden in clay, loamy, or sandy soils.

Burnsville Stormwater Retrofit Study - To limit large volumes of stormwater runoff, the City of Burnsville, Minnesota installed an experimental raingarden system to infiltrate street runoff. To better document the performance capacity of the raingardens, this project involved the completion of a "paired watershed" study, in which two very similar residential areas are monitored - one control watershed with a traditional curb and gutter system, and one test watershed with 17 new raingardens within a 25-lot, 5.3-acre neighborhood. Both the control and treatment watersheds were monitored before and after raingarden construction to facilitate the statistical evaluation of the paired watershed data.

Permeable Pavements

Interlocking Concrete Pavement Institute (ICPI) - ICPI’s mission is to increase the use of segmental concrete pavement systems in North America. Their website features extensive information on permeable interlocking concrete pavement (PICP), including separate fact sheets for developers, municipalities, design professionals, schools, plus various PowerPoint presentations. Content includes a comparison guide for PICP, pervious concrete, and porous asphalt.

Hydr ologic and Water Quality Comparison of Four Types of Permeable Pavement and Standard Asphalt in Eastern North Carolina (PDF) (91 pp, 1.3MB) - This report, published by North Carolina State University and the Interlocking Concrete Pavement Institute, provides monitoring data from a parking lot with four different types of permeable pavements as well as traditional asphalt. The parking lot was monitored from July 2006 - July 2007 to identify hydrologic and water quality characteristics associated with different types of porous and impervious pavements.

Long-Term Stormwater Quantity and Quality Performance of Permeable Pavements Systems (PDF) (15 pp, 293K) - This University of Washington study examined the long-term effectiveness of permeable pavement as an alternative to traditional impervious asphalt pavement in a parking area. Four commercially available permeable pavement systems were evaluated after six years of daily parking usage for structural durability, ability to infiltrate precipitation, and impacts on water quality via infiltration.

Vegetated Swales

Portland's Stormwater Solutions Handbook - This segment of Portland's Stormwater Solutions Handbook contains information on many green infrastructure techniques, including vegetated swales. Note: EPA cannot promote the use of dry wells in conjunction with vegetated swales.

Seattle's High Point Community Site Drainage Technical Standard - Seattle's High Point neighborhood, a redevelopment project, contains a variety of green infrastructure practices throughout the development. This technical guide provides information on vegetated swales under the "Conveyance Zone Options" section.

Brownfield Redevelopment

Design Principles for Stormwater Management on Compacted, Contaminated Soils in Dense Urban Areas (PDF) (4 pp, 809K) - Describes basic guiding principles when integrating green infrastructure at a brownfield site. A key component is treatment and storage of stormwater, rather than complete infiltration.

Case Studies for Stormwater Management on Compacted, Contaminated Soils in Dense Urban Areas (PDF) (4 pp, 410K) - Highlights of successful green infrastructure projects at brownfield sites around the country: Emeryville, CA, Dearborn, MI, and Pittsburgh, PA.

Infill and Redevelopment

Stormwater Guidelines for Green Dense Redevelopment, Emeryville - EPA recently supported the City of Emeryville, California in the development of "Stormwater Guidelines for Green, Dense Redevelopment." Emeryville, which is a suburb of San Francisco, has worked for over a decade on reclaiming, remediating and redeveloping the many brownfields within its borders. The guidelines, and an accompanying spreadsheet model, were developed to make as much use of redevelopment sites as possible for handling stormwater.

Green Parking

Toronto City Planning Design Guidelines for 'Greening" Surface Parking Lots (PDF) (40 pp, 9.8MB) - The draft Design Guidelines for 'Greening' Surface Parking Lots (approved for public release and comment November 2007) provide specific strategies and measures which developers, designers and reviewers of surface parking lots can apply to help meet Official Plan policies and environmental performance targets of the Toronto Green Development Standard. The Guidelines are designed to deal with common urban design and environmental challenges found within and around surface parking lots. 'Greening' the surface parking lot involves: planting trees; providing good quality soil and generous landscaped areas; enhancing pedestrian and cycling infrastructure; managing stormwater on-site; reducing the urban heat island effect; and using sustainable materials and technologies.

Green Parking Lot Case Study (PDF) (9 pp, 34K) - Heifer International, a non-profit sustainable community development organization, published this case study on the environmental impacts associated with parking lots and identifies techniques that can be used to mitigate them. The report includes information on the environmental benefits and costs of green parking, and also explores ideas for developing policies that encourage the use of green parking lot techniques.

Urban Design Tools, Bioretention - Contains examples and basic explanations of successful bioretention case studies, compiled by the Low Impact Development Center.

Green Streets & Highways

Green Streets: A Conceptual Guide to Effective Green Streets Design Solutions (PDF) (7 pp, 5.86MB) - Guidance for green design solutions to include: Residential Streets, Commercial Streets, Arterial Streets, and Alleys.

Northern Kentucky Stormwater Management Handbook (PDF) (119 pp, 17.4MB) - Faced with rapid growth pressures and a burdened combined sewer system that frequently overflows, Sanitation District No. 1 in Northern Kentucky has identified land use policies and strategies that address stormwater concerns and create attractive, walkable neighborhoods. The handbook illustrates innovative site level design strategies that reduce runoff from development and how they could be successfully applied in Northern Kentucky. The strategies, policies, and designs, which are applicable elsewhere, provide communities in Northern Kentucky with environmentally responsible planning and design alternatives that can reduce water pollution, decrease runoff volume, protect aquatic habitat, and have the additional community benefit of creating more interesting places to live, work and play.

UC Davis Sustainable Transportation Center Sustainable Streets Project (Word documents and PowerPoint Presentations) - The role of urban street design in advancing sustainability goals is the focus of the Sustainable Streets project. The project highlights the connections between urban street design and sustainability; introduces a three-part framework for street design addressing community, ecology and movement; and documents accomplishments in street design that are built or under construction by early 2008, with 28 American and Canadian case studies in 11 states and provinces. The case studies documented are organized according to four themes, one of which is "Stormwater Plus" that include projects designed with implementation of stormwater management features as a primary design objective.

Protecting Water Quality with Smart Growth Strategies and Natural Stormwater Management in Sussex County, Delaware (PDF) (119 pp, 10.51MB) - The purpose of this report is to: 1) Describe how smart growth and sustainable stormwater management approaches could be applied to Sussex County; and 2) Provide site-level stormwater design strategies that could be used to manage stormwater at the scale of a front yard, neighborhood street, parking lot, or development parcel. Chapter 5 presents examples of how to incorporate stormwater facilities into a range of street types from residential alleys to downtown commercial streets.

San Mateo County Sustainable Green Streets and Parking Lots Design Guidebook (PDF) (174 pp, 41.1MB) (The first edition of this guidebook was released in January 2009 by the San Mateo County Water Pollution Prevention Program) - Prepared by Nevue Ngan Associates and Sherwood Design Engineers, the guidebook provides designers, builders, municipal staff, and others practical and state-of-the-art information on using green infrastructure management practices. The guidebook addresses conditions found in San Mateo County, however, the concepts and information presented may be useful for other region’s street and parking lot scenarios.  Chapters cover: green streets & parking lots, providing site layout and stormwater facility strategies, details on street and parking lot conditions in San Mateo County, design examples for the various street and parking lot scenarios within the county, discussion on key design and construction details, and conceptual designs for demonstration projects being constructed in the county.  The Guidebook and demonstration projects are funded using vehicle license fees collected in San Mateo County to address stormwater pollution issues associated with vehicles and transportation infrastructure.

Low Impact Development (LID) Center Green Streets - The LID Center, a non-profit 501 (c) 3 organization that focuses on water resource and sustainable design, has been working to develop strategies for the integration of green and grey infrastructure for over 10 years. This website provides information on basic research, pilot projects, standards and specifications, planned and constructed projects that the Center has been involved in across the country through work with the EPA, National Academy of Sciences, Federal Highway Administration, State and Local Department of Transportation agencies, Municipal Planning Organizations, and industry. Links to other green streets programs can also be found on the site.

From Gray Funnels to Green Sponges Podcasts: Green Streets - This podcast includes an interview with Clark Wilson, Senior Urban Designer for EPA’s Smart Growth Program, discussing how green streets are used for stormwater management. Download the PowerPoint presentation at http://www.clu-in.org/live/archiveowow.xml

U.S. Green Streets Initiatives - EPA's Office of Wetlands, Oceans, and Watersheds website provides links that highlight green street initiatives from around the United States.

City of Portland, Green Street Program - Portland Bureau of Environmental Services promotes green streets to manage stormwater runoff; website includes map of green streets within the city, along with American Society of Landscape Architects award winning locations.

Seattle Public Utilities, Street Edge Alternatives (SEA Streets) Project - Alternative to traditional street drainage design has reduced total volume of stormwater leaving the street by 99 percent.

Green Highways Partnership - Promotes creative design and technologies in making the country's highways more sustainable. Provides information on the three major components of the Green Highway process: planning and preliminary design, final design and construction, & operations and maintenance.

The Chicago Green Alley Handbook (PDF) (24 pp, 3.72MB) - Illustrates numerous techniques for the greening of city alleys, including permeable pavement and recycled construction materials. The handbook also suggests techniques that homeowners can implement themselves to make their properties more environmentally-friendly.

Pocket Wetlands

Send arazan.nancy@epa.gov good examples!

Trees & Urban Forestry

Casey Trees - A Washington-based organization dedicated to restoring, enhancing and protecting the tree canopy of the nation's capitol.

Center for Watershed Protection's Urban Forestry Series - In cooperation with the USDA Forest Service, Northeastern Area State and Private Forestry, has produced a three-part manual series on using trees to protect and restore urban watersheds.

San Francisco Bay Area State of the Urban Forest Final Report (PDF) (92 pp, 2.5MB) - The USDA Forest Service's Center for Urban Forest Research recently released their study of the urban tree canopy of the San Francisco Bay area. The report had three goals: (1) to describe the historic changes to the region's urban canopy cover and amount of impervious surface, (2) to quantify the value of ecosystem services the current forest provides, and (3) to estimate future benefits based on possible expansion of the urban forest. It's full of interesting information for Bay area residents and anyone who would like to know more about the benefits of trees.

The Sustainable Urban Forests Coalition - A national coalition to advance a unified urban forest agenda for our nation's communities. The Coalition views urban forests as the aggregate of all vegetation and green spaces within communities that provide benefits vital to enriching overall quality of life.

TreePeople - A nonprofit organization that promotes various urban forestry initiatives through education, planting projects, policy development and research.

Riparian Buffers

Virginia Cooperative Extensions, Understanding the Science Behind Riparian Forest Buffers: Planning, Establishment, and Maintenance - Provides fundamental guidance on assessing current riparian forest buffer health and recommendations on the design and restoration process. Watershed conditions and immediate adjacent land uses are important in determining the projected functional use of the riparian forest, along with plans for maintenance are integral to a functional riparian forest buffer.

Approaches for Green Infrastructure Design

Northern Kentucky Stormwater Management Handbook - Sanitation District No. 1 in Northern Kentucky strives to find and use innovative practices for protecting and improving water quality. Faced with rapid growth pressures and a burdened combined sewer system that frequently overflows, the sanitation district has identified solutions that allow for sustained economic growth without exasperating overflows or harming water quality.

This handbook includes land use policies and strategies that both addresses stormwater concerns and creates attractive, walkable neighborhoods. The handbook also illustrates innovative site level design strategies that reduce runoff from development and how they could be successfully applied in Northern Kentucky. The strategies, policies, and designs illustrate the handbook’s goal–to provide communities in Northern Kentucky environmentally responsible planning and design alternatives that can reduce water pollution, decrease runoff volume, protect aquatic habitat, and have the additional community benefit of creating more interesting places to live, work and play.

EPA project manager: Clark Wilson (202-566-2880, wilson.clark@epa.gov)

The Green Infrastructure Guide: Issues, Implementation Strategies and Success Stories (PDF) (88 pp, 1.2MB) - The Green Infrastructure Guide is a product of the West Coast Environmental Law Research Foundation in British Columbia. It provides guidance on how local governments may, using legal and policy strategies, encourage or require more sustainable infrastructure designs. It refers readers to strategies, and highlights case studies of local governments that have already taken steps to incorporate a green infrastructure approach. The focus is on implementation mechanisms, issues and barriers, and on what lessons have been learned from experiences to date.

Local Water Policy Innovation: A Road Map for Community Based Stormwater Solutions (PDF) (50 pp, 2.33MB) - Describes how to work with local government officials and staff to remove implementation barriers and offer incentives for green infrastructure. This document emphasizes that building community awareness and support for green infrastructure practices is a simple, yet significant component to achieving communities that implement green infrastructure. Troubleshooting municipal codes and ordinances is also included; for example, removing storm sewer connections requirements and integrating green infrastructure into existing landscaping requirements. Case studies throughout the document provide context and examples for all themes discussed.

Blue Cities Guide: Environmentally Sensitive Urban Development (PDF) (40 pp, 7.38MB) - Produced by the Charles River Watershed Association, this guide presents three case studies which shaped the comprehensive Blue Cities approach. This approach addresses common problems of urban water environments, such as flooding, groundwater recession, eutrophication, combined sewer overflows, and thermal pollution.

Parking Spaces / Community Places: Finding the Balance through Smart Growth Solutions (PDF) (70 pp, 3.43MB) - Describes approaches that can help communities explore new, flexible parking policies that can encourage growth and balance parking needs with their other goals. The report also demonstrates the significance of parking decisions in development patterns and presents case studies of places that are successfully using these strategies.

Protecting Water Resources with Higher-Density Development (PDF) (46 pp, 1.35MB) - Helps communities better understand the impacts of higher and lower density development on water resources. The findings indicate that low-density development may not always be the preferred strategy for protecting water resources.

Using Smart Growth Techniques as Stormwater Best Management Practices (PDF) (112 pp, 1.6MB) - Reviews nine common smart growth techniques and examines how they can be used to prevent or manage stormwater runoff.

Using Rainwater to Grow Livable Communities - Provides tools and resources for integrating stormwater controls into development projects as well as case studies that examine integration in several cities across the United States.

Low Impact Development: Technical Guidance Manual for Puget Sound (PDF) (256 pp, 7.7MB) - This guidance manual, developed by the Puget Sound Action Team and Washington State University, is designed to provide stormwater managers and site designers with a common understanding of green infrastructure goals and objectives. It includes technical specifications for individual practices as well as research data related to those practices.