Working with Nature: Stormwater Parks
As summer officially starts, and your community is looking for ways to make the best of the outdoors, join us as we explore three urban parks that exemplify the role stormwater management features can play in making public spaces successful. Get inspired by their examples, and reach out to SSDN’s Environmental Finance Center. We can provide technical assistance to help transform your infrastructure into community assets.
Trends in park design have evolved over the last two centuries to accommodate an ever-expanding list of needs, from skateparks to pickleball courts to flood and heat mitigation. While parks may never be able to serve every desire, they excel at efficiently offering multiple benefits including a community space to socialize, opportunities to strengthen physical and mental wellbeing, ecological support for urban fauna and flora, and as infrastructure for drinking, storm, and even wastewater.
Stormwater parks, as characterized by CNT, “serve a dual role as recreational parkland that also hold a large amount of water during storms. These parks treat rain as an asset, by incorporating stormwater management into the overall landscape design.” They typically showcase a combination of gray and green infrastructure by serving a sizable area of developed land, with a wet pond receiving stormwater as the main feature. Their design intentionally assists with stormwater management, by capturing, infiltrating, and treating runoff.
Looking at examples of stormwater parks in the Southeast, several commonalities in their intent and layout arise. These parks are often located in scarred and problematic urban sites, prone to flooding, and transform a stormwater problem into a community amenity. Funding these large assets comes with its lot of challenges, especially when land availability is limited, and most large stormwater parks are supported by conservancies to help with ongoing maintenance and public programming.
Historic Fourth Ward Park, Atlanta, GA
Photo by Catherine Mercier Baggett
Historic Fourth Ward Park in the city of Atlanta, GA, is a well-documented case study that illustrates how green stormwater infrastructure can assist with regulatory compliance, and at a competitive cost. Built in the 2010s to accommodate millions of gallons of runoff, the detention basin has become the centerpiece of a massive residential and commercial redevelopment.
The site that would become this 17.5-acre park served surprising uses previously that include an amusement park at the turn of the 20th century and vast parking lots serving low-density warehouses that regularly flooded. The park concept emerged at the intersection of consent decrees to resolve important water issues (including combined sewer overflows) and the creation of the Beltline, a transformative rail-to-trail project that now connects central neighborhoods with a greenway dotted with parks and urban development.
Driven by a citizen effort, the vision for the park emphasized using stormwater as an asset. The design centers around a 2.5-acre pond with aquatic vegetation that collects stormwater runoff, and the planting beds and path above the waterline are designed to be submerged without damage during especially heavy rainfalls.
The permanent pool can maintain seven million gallons of water, the equivalent of a 100-year flood volume. It temporarily stores storm runoff and slowly releases, helping abate the combined sewer overflows targeted by the consent decrees. The system serves a total area of 850 acres, and stormwater peak flow reduction is estimated to be over 9%. It also provides water quality benefits, by letting suspended solids settle.
The financial considerations of the project also supported the creation of a pond rather than underground pipes: the $18M construction cost (originally budgeted at $23M) is estimated to be less than half the amount that a traditional gray infrastructure project would have required. Further, an underground system could never become a beloved and sought-after community amenity.
Pulling the resources together to deliver Historic Fourth Ward Park required the coordination of several partners. The properties were acquired with the support of the Trust for Public Land and the Woodruff Foundation, and the construction was funded through the City of Atlanta Department of Watershed Management and the Beltline Tax Allocation District (TAD), a tax increment financing instrument that allows revenue generated by local commercial development to be invested within the same area. Together, the park and the Beltline catalyzed monumental investment in thousands of new housing units, offices, and commercial spaces that occupy previously underused land.
Historic Fourth Ward Park brought recognition to the City of Atlanta as a strong regional leader for green infrastructure implementation. The park also played a role in the development and adoption of the Green Infrastructure Strategic Action Plan in 2018, which set the goal to reduce stormwater runoff volume by 225 million gallons – that represents a 1% volume reduction of runoff from a 1” storm. A year later, the City passed an Environmental Impact Bond (EIB) to assist with the construction of additional stormwater parks and other projects.
Railroad Park, Birmingham AL
Photo courtesy of Railroad Park
While the City of Atlanta was finalizing Historic Fourth Ward Park, the City of Birmingham was inaugurating Railroad Park, a 19 acre greenspace that features open lawns, a walking path, formal gathering places, native plantings, and playgrounds.
The park extends over land that sits at one of the lowest elevations in the city, between the still-active main railroad corridor and Region Fields baseball park. Runoff naturally collected in this area that was marshland prior to industrial development in the early 1900s. Taking advantage of the brickyard and other land uses that once stood in the same place, a large portion of the hardscape materials used to construct the park were salvaged on site. Water occupies approximately one-third of the park’s area, with a large pond providing the main feature. The reservoir is used for irrigation and replenished by stormwater runoff. A system of streams and wetlands improves water quality and offers a unique experience to play in the water, in a city where there are otherwise no major rivers or lakes.
As it is the case with most complex infrastructure projects, going from vision to ribbon-cutting required a creative stack of funding sources. According to The Trust for Public Land, the park came to life through contributions from the City of Birmingham, Jefferson County, a Congestion Mitigation and Air Quality grant from the Federal Highway Administration, Alabama Power, the Community Foundation of Greater Birmingham, private donations and a loan from the Regions Bank (the namesake of the adjacent ballpark). Design and construction amounted to $23M (originally budgeted at $17.5M), but helped spur hundreds of millions of dollars in private development surrounding the park.
The Railroad Park is now a connecting piece in the expanding pedestrian framework that is both a contributor and a result of the transformation occurring south of downtown.
Renaissance Park, Chattanooga, TN
Photo courtesy of Visit Chattanooga
Until the early 2000s, the parcel of land located in the floodplain on the northwest side of Market Street Bridge in Chattanooga, TN, that would become Renaissance Park was a typical brownfield, with an aging industrial building and surface parking lots. Semi-volatile organic compounds and heavy metals that contaminated the soil were leaching into groundwater and running off into the Tennessee River.
In contrast to adjacent Coolidge Park, which was designed for active use with large lawns, a splashpad and a carousel, Renaissance Park instead showcases local ecosystems. An existing patch of forest was preserved, and the rest of the 23-acre site was turned into small gathering spaces, trails, native plant meadows and a constructed wetland. The project integrated the encapsulated contaminated soil into the park design by shaping it into geometrical landforms two feet above the flood elevation. In the depression left behind by the removed soil, a constructed wetland treats runoff before releasing it into the river through a series of low walls with plantings that slow down the flow of water. Unlike Railroad Park, the public is not invited to physically interact with the water, but rather observe and appreciate the whole ecosystem from the manmade hill and the elevated pedestrian bridge.
At the cost of $8M, this project is estimated to have been 25% less expensive than a traditional “hard” engineering approach, as reported by the Landscape Architecture Foundation. Over the last 40 years, the city has reclaimed its waterfront, parcel by parcel, from obsolete industrial uses and is bringing to life a comprehensive vision for a ribbon of uninterrupted public amenities. Renaissance Park is only one piece of this transformation that started with Vision 2000, a plan devised by Chattanooga Venture in the early 1980s when the city was still recovering . River City Company, the economic development enterprise for downtown Chattanooga, spurred the revitalization with $12M in philanthropic seed funds. Renaissance Park is an integral part of a collective effort that continues to be supported by the community, private investors, and local and state governments, and its impact on quality of life and economy cannot be teased out from the overarching riverfront framework.
Now fully embracing “Nature as part of everyday life“, Chattanooga shed its infamous title of “Dirtiest City in America” to become the first National Park City in America in 2025.
Conclusion
Each of these parks exemplifies a planning approach that puts large-scale stormwater infrastructure at the forefront of the design, and uses it as a community revitalization asset.
If your community is ready to explore stormwater infrastructure projects, contact SSDN’s Environmental Finance Center. We can provide no-cost technical assistance with developing a program, exploring green stormwater infrastructure feasibility, or identifying a funding and financing strategy.
