Stormwater Capture & Use

As a key tenet of our Vision for Sustainable Stormwater Management, CASQA is working to maximize stormwater capture.

Capturing water in our communities and protecting our water resources provides substantial value with healthier, more livable, and more resilient communities. An investment in stormwater capture is also an investment in flood control, green infrastructure, street beautification, sanitation, water conservation, and groundwater recharge.

With changing precipitation patterns and declining snowpack, capturing stormwater in our urban communities must occur to adapt to climate change and long periods of drought. Our flood control systems were designed to capture and move water from urban landscapes as fast as possible, so that even when experiencing extreme drought, the majority of our rainwater simply washes out of our communities. Stormwater is a critically untapped resource, and our state’s infrastructure must be updated to capture as much as possible to benefit our waterways and communities.

Research and Actions on Urban Stormwater Capture

In a partnership with Ceto Consulting, which brings over four decades of experience in economics, geomorphology, and land use planning, CASQA is proud to present The Socioeconomic Value of Urban Stormwater Capture (PDF). The report details the substantial socioeconomic benefits that can be realized from urban stormwater capture projects.

The study utilized an extensive literature review to estimate monetary values for five socioeconomic benefits – Community Health, Water Quality, Green Space, Recreation, and Wetlands – for four stormwater capture and use projects. The projects included Earvin “Magic” Johnson Park (Los Angeles), Orange Memorial Park (South San Francisco), the San Mateo Sustainable Streets Master Plan, and the Fresno Metropolitan Flood Control District’s converted retention basins.

Key Takeaways:

  • An increased investment in urban stormwater capture is not only beneficial for augmenting water supply and improving flood control but also yields significant socioeconomic returns.
    • The annual dollar value of the benefits estimated in this report alone exceeded the total cost of the project. In other words, all of these projects have a one-year payoff.
    • In a typical benefit/cost analysis, one would examine a multi-year period equal to the life of these projects, such as 20 years. It is highly unusual to find a one-year return.
    • This one-year return indicates underinvestment in urban stormwater capture and that more public investment in this space would likely yield extremely high returns in terms of community benefit.
  • The non-market value of the socioeconomic benefits of urban stormwater capture projects can be maximized by siting these projects in areas of highest need. A project which creates urban green space in a high-need area will maximize benefits to the community.
    • The analysis of underserved communities using CalEnviroScreen estimated that the benefits for Orange Memorial Park increased from $47 to $56 million based on the vulnerability of the community and the lack of usable greenspace in proximity.
    • A similar story emerges in Earvin “Magic” Johnson Park in Los Angeles. Applying an adjustment for the additional benefits to underserved communities yields an estimated 30% higher return, since Earvin “Magic” Johnson Park serves a highly vulnerable community.

Subcommittee

Through the Stormwater Capture and Use Subcommittee, CASQA is leading the way in California to advance this critical research and work. To engage with the leaders in this field, we encourage you to participate.