Incorporating a Multiple-Benefit Analysis into a Stormwater Decision-Support Tool at Planning Level

Abstract

As we move into an era of increased urbanization, stormwater practitioners are charged with creating multibenefit solutions through the installation of stormwater control measures (SCMs). Two drivers facilitate the accrual of benefits in SCMs: hydrologic or water quality process and vegetation. This study investigated the feasibility of incorporating benefits beyond water quality and quantity control into the SCM planning process. A critical review was used to determine which benefits would be assessed with hydrologic and water quality modeling or a complementary conceptual framework. Drawing on common themes in the literature, the conceptual framework of the 4 Cs (community, context, connectivity, and canopy) was created to assess vegetation-based benefits. To demonstrate the coupled benefit assessment, a case study was performed in a neighborhood of Denver, Colorado. Results from hydrologic and water quality modeling show that vegetated swales provide the most preferred solution. From the vegetation-based benefit perspective, we find that the modeled area of the vegetated swales is only 0.2% by area, which is likely too small to have a measurable benefit effect at the neighborhood scale. We show how the 4 Cs can be used to leverage existing greenness to maximize the potential vegetation-based benefit of swales and consider how existing sociodemographic and vegetation trends can be leveraged to make benefit-driven decisions.