Decentralized Stormwater Source Controls for Urban Retrofit and Combined Sewer Overflow Reduction

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About the Report

In 2006, this report synthesized the results of a research initiative commissioned by the Water Environment Research Federation (WERF). The research purpose was to help define the  state-of-the-practice regarding decentralized source controls for capturing rainwater where it falls; and to present a plan for implementation of decentralized controls in an urban environment specifically for the goal of CSO mitigation.

The primary focus of the applied research was how decentralized controls can reduce the volume of rainwater runoff generated and, consequently, entering the combined sewer system in urban areas.

Executive Summary

Rainwater runoff that is diverted from roads, rooftops, and parking lots during storm events contributes to combined sewer overflows (CSOs). Decentralized controls, also known as best management practices, manage rainwater runoff on a small scale, and are constructed to capture rain where it falls. These controls use natural hydrologic cycle elements (such as infiltration and evapotranspiration) to dampen stormwater surges that overwhelm combined systems.

Neil-Weinstein_LID Center_120p“Capturing rainwater where if falls offers appealing technical alternatives to stormwater runoff capture than conventional end-of-pipe measures. Decentralized controls have the potential to reduce the frequency and volume of CSO events. In addition, a decentralized approach to stormwater management allows communities the flexibility to respond to everchanging economic and environmental conditions,” stated Neil Weinsten, Executive Director of the Low Impact Development Center, and project manager for the WERF report.

Capturing runoff where it falls in urban areas introduces ancillary benefits into the community that extend beyond runoff volume reduction. The use of decentralized source controls in conjunction with redeveloping land in urban regions creates opportunities, over time, to develop greener communities that will achieve higher levels of ecological and receiving water protection.

To Learn More:

To read an overview, click on Executive Summary: Decentralized Stormwater Controls for Urban Retrofit and Combined Sewer Overflow Reduction (2006).

To order a copy of the complete report from WERF, click on Decentralized Stormwater Controls for Urban Retrofit and Combined Sewer Overflow Reduction.

Posted December 2009