Assessment of Bioswale Performance to Manage Urban Stormwater Runoff

Vegetated stormwater control measures (SCMs) are widely designed and implemented to mitigate stormwater runoff and improve water quality. The type, number, and location of the SCMs are key parameters that determine their effectiveness on stormwater management. This research focuses on utilizing the Low Impact Development (LID) Control module in the EPA Storm Water Management Model (SWMM) to evaluate the performance of SCMs installed at Naylors Run watershed, a tributary to Cobb’s Creek located in Delaware County, PA. Two bioswales were designed to convey stormwater from impervious areas and reduce peak flows by increasing travel time, enhancing infiltration, and improving water quality. A geographic information system (GIS) was used to determine the watershed characteristics as the inputs for the SWMM modeling. The model was calibrated using the measured flow rate and depth upstream and downstream of the bioswales. The potential design modifications in the existing SCMs at the Naylors Run watershed will be discussed such as, bioswale sizing, conveyance structures and underdrain system.