Monitoring the Effectiveness of Bioretention Cells

U.S. Geological Survey (USGS) Nebraska Water Science Center (NEWSC) scientists are using site-specific scientific data from three bioretention cells in Omaha, Nebr., to evaluate and validate green infrastructure Best Management Practices (BMPs). Green infrastructure, which stresses the importance of capturing, retaining, and treating stormwater, is gaining consideration as an effective form of stormwater management. One green-infrastructure BMP that helps mitigate the effects of stormwater on flooding and water quality is bioretention cells.

A bioretention cell is a BMP that captures and treats stormwater, by promoting evapotranspiration and infiltration, thereby reducing the quantity of stormwater. We are monitoring three bioretention cells in Omaha to evaluate the effectiveness of the cells on reducing stormwater runoff as well as determining which factors, such as soil type, vegetation, evaporation rate and cell design, may be affecting performance. The first two cells, at the Douglas County Health Center (DCHC) and the Eastern Nebraska Office on Aging (ENOA), are being monitored in cooperation with Douglas County and the Nebraska Environmental Trust. The third cell at the Omaha Sewer Maintenance Facility (OMSF) is being monitored in cooperation with the U.S. Environmental Protection Agency and the City of Omaha.

Additional details about the design of the bioretention cells, data being collected, and computation of the water balance are available from the DCHC, ENOA, and OSMF tabs above or from the links below the photos.

Why are Bioretention Cells Needed in Omaha?

Sanitary and stormwater sewers in Omaha use a combined pipe system called a combined sewer overflow (CSO). When rainfall is greater than approximately 0.1 inches, the stormwater runoff exceeds the capacity of the combined sewer system causing raw sewage to be discharged into Papillion Creek. Bioretention cells can mitigate the effects of stormwater on flooding and water quality by collecting and retaining stormwater.