Green Infrastructure Toolkit
Being Strategic: Tools to Choose Pilot Sites
To maximize the benefits of green infrastructure installations, decision makers must be strategic in choosing pilot site locations. By clearly defining the goals of a pilot program, local governments can decide which types of installations and which specific locations will best achieve these goals.See footnote 1 The most common goals that local governments tend to consider include reducing strain on the stormwater and wastewater management systems, reducing watershed pollution, reducing flooding, creating public education opportunities, reducing carbon emissions, and addressing other effects of climate change (increased urban heat island, excess runoff due to more severe, less predictable weather patterns). Some local governments take a more holistic approach to maximize both the impact of the investment and the public good.See footnote 2
Designing with green infrastructure often fits within a city’s larger sustainable development goals.See footnote 3 By considering the co-benefits of green infrastructure (including social, economic and environmental values), decision makers are able to get the most “bang for the buck” from their stormwater management investment.See footnote 4
This section offers decision makers a variety of successful tools for choosing sites for green infrastructure programs, drawn from practices around the country. The three basic models that this chapter covers include 1) a Priority Watersheds approach, which focuses on water quality almost exclusively and is the most traditional of the three; 2) a Public Input-Based Approach, which explicitly incorporates community priorities; and 3) a Score Ranking approach, which allows a local government to delineate a full set of priorities and rank the sites using those priorities.
This chapter analyzes each of the three approaches using a set of four criteria to enable local governments to decide among them.
- Co-Benefits: Some approaches more easily incorporate and maximize co-benefits, which may range from reduced flood risk, improved air quality, improved public health, financial savings, and more.See footnote 5 Intentionally comprehensive green infrastructure programs may create the most robust benefits.
- Flexibility: A flexible approach allows decision makers to choose pilot sites based on specific pre-established priorities. A flexible approach can more easily accommodate interagency collaboration, public input, and various outcome goals. A flexible approach can also readily account for adaptive management and comprehensive planning goals.
- Administrative Burden: Some approaches are administratively more burdensome than others, requiring more staff time and resources, for example. This criterion assesses how burdensome each approach is in terms of interagency partnerships, program management, and efficiency in implementation.
- Public Participation: This criterion measures an approach’s tendency to meaningfully incorporate public input. This may include meaningful community engagement strategies, consideration of equity and environmental justice issues, and long-term community goals.
Priority Watersheds Approach
In an urban setting, combined sewer overflows (CSOs), flooding, and other problems that arise from excess runoff are symptomatic of overburdened systems and high percentages of impervious surface.See footnote 6 To mitigate these effects, local governments can incorporate green infrastructure on a watershed scale to reduce the total volume and velocity of stormwater runoff to traditional sewer systems.See footnote 7 To meet this set of priorities, local governments first identify tributary areas and construct green infrastructure on sites designed and placed to maximize stormwater retention and water quality benefits.See footnote 8
This approach, by focusing on the water quality priorities within particular watersheds, can create a comprehensive picture of the causes of and remedies for water pollution. Taking a priority watershed approach is appropriate for local governments that are primarily concerned with pollution control in watershed outflows, and can be an effective methodology in green infrastructure development aiming to serve Clean Water Act compliance goals.
A priority watershed approach is efficient for stormwater management purposes. However, because it is most often designed with a singular focus for water quality goals, it may have fewer opportunities for triple bottom line co-benefits.
Public Input-Based Approach
Local governments can address community priorities by engaging the local population in their planning processes while choosing and designing publicly funded projects. Surveys, community workshops, open comment periods, and other direct outreach efforts can supplement project environmental goals and can enhance community support.See footnote 9 A public input-based approach is flexible and fosters community buy-in; however, it can be time- and resource-intensive to carry out a robust a public process that results in meaningful engagement.
When the public can participate in the planning process, pilot site installations will better respond to community needs and be tailored to achieve community priorities.See footnote 10 This can be particularly transformative for communities facing environmental justice concerns such as lack of access to green space or playgrounds, those with disproportionately poor air quality, food deserts, or living with urban heat island effects.See footnote 11 Furthermore, policy makers should be aware that while green infrastructure can enhance local economies via higher property values, this might also increase living costs for low-income residents and accelerate gentrification.See footnote 12 Public input and community collaboration can help frame project planning and provide critical information for the long-term success of green infrastructure programs, which may need to be paired with affordable housing or other equitable development policies.
Score Ranking Approach
Decision makers can use a score ranking approach to set program goals and priorities, and to ensure that the chosen pilot sites achieve those priorities. A comprehensive scoring system allows decision makers to rank projects across a set of diverse factors (such as potential for reducing runoff or pollutants, maintenance burdens, educational opportunities, and other co-benefits). This ranking then enables decision makers to create a model for strategically selecting projects based on those factors.See footnote 13 For instance, a local government might consider scheduled transportation construction in a site’s score. The construction window for road maintenance provides a cost-effective opportunity to install permeable pavement, right-of-way bio-swales, or other green infrastructure.See footnote 14 The success of this approach requires close inter-agency collaboration that may include the departments of transportation and public works, among others that can help to increase the public investment’s utility and efficiency during construction.See footnote 15
Using a scorecard approach requires decision makers to think carefully about the goals that are most important to them and the types of projects and practices that are most likely to achieve those goals, but also provides a high level of flexibility to set those goals. Setting up those criteria and ranking potential sites may be time intensive. This approach also requires intensive planning and potentially cross-sector collaboration in advance of choosing sites.
Milwaukee, Wisconsin Regional Green Infrastructure Plan
Storm Lake, Iowa Green Infrastructure Plan for Water
Milwaukee Metropolitan Sewerage District (MMSD) has established a 2035 Vision for “zero basement backups, zero overflows, and improved water quality.” To achieve these goals, MMSD has transformed its approach to managing stormwater by utilizing green infrastructure technologies in its urban watershed management plan. By implementing widespread use of green infrastructure (GI) to complement the region’s grey infrastructure, the Regional Green Infrastructure Plan documents how to meet the 2035 goal by capturing the first 0.5 inch of rainfall on impervious surfaces, the equivalent of 740 million gallons of stormwater storage. The plan identifies the best GI strategies, presents a cost-benefit analysis, and make recommendations to ensure implementation.
Stormwater Management Toolkit: Urban Watershed Planning Game
In 2014, the City of Storm Lake, Iowa was chosen for a pilot project by the Iowa Economic Development Authority to develop a plan for city-wide green infrastructure technology for improved urban water management - including storm, sanitary, and potable water solutions. This Plan is meant to serve as a case study and guidance document for green infrastructure planning in other communities. The Plan demonstrates a process that can be replicated and scaled to any size city.
Greater New Orleans Urban Water Plan
As part of the Stormwater Management Toolkit, San Francisco Public Utilities Commission (SFPUC) developed the Urban Watershed Planning Game. This game helps the SFPUC understand community priorities by presenting a diverse group of community members with the task of updating San Francisco’s sewer system. The game fosters the development of green infrastructure solutions that help San Francisco adapt to the impacts of climate change in a financially feasible, community driven manner. This game is a great resource for city planners, watershed managers, public engagement officers, and citizens.
San Francisco Public Utilities Commission Green Infrastructure Projects
The Greater New Orleans Urban Water Plan focuses on the improved management of storm water, surface waters and groundwater in New Orleans, Louisiana, in response to flooding, land subsidence and “wasted water assets.” The primary area of focus is 155 miles of urban areas and 69 square miles of protected wetlands in Orleans, Jefferson and St. Bernard parishes. The plan discusses how climate change threatens to raise the frequency of extreme weather events, and rising sea levels. Considered along with land subsidence, residents and economic assets are at great risk - and pumping stormwater and keeping floodwaters out are both projected to become more difficult over time.
Arlington, Virginia Watershed Retrofit Study
San Francisco Public Utilities Commission (SFPUC) is implementing multiple green infrastructure projects based on their Urban Watershed Assessment, which will identify green and grey sewer infrastructure improvements over the next twenty years. The SFPUC recognizes that the sewer system, treating both sewage and stormwater runoff, was not built to withstand the impacts of climate change - such as intense rainstorms that overwhelm the system. The watershed-based planning process is being used to help plan the City’s Sewer System Improvement Program (SSIP), a multi-billion dollar project to to upgrade aging infrastructure, and ensure the reliability and performance of the sewer system.
Completed in December, 2013, Arlington County, VA produced a Watershed Retrofit Study and plans with the purpose of strengthening the resiliency of its stormwater management systems to climate change. Arlington developed a County-wide project inventory by surveying all of the County's watersheds to find space for small stormwater facilities. This study informed the City of Arlington’s Stormwater Master Plan, which was adopted in Sept. 2014.