Water Quality Capture Volume for Storm Water BMP and LID Designs

AbstractThis paper summarizes the methodology and procedure used in an optimization and statistics computer model developed for determining the water quality capture volume (WQCV) for storm water best management practices (BMP) and low-impact development (LID) facility designs. The WQCV is directly related to the local rainfall pattern, watershed imperviousness, and drain time applied to BMP/LID storage devices. Aided by a computer model, the performance of a LID/BMP basin can be predicted using the local rainfall-runoff continuous simulation that computes the long-term runoff volume-based and event-based capture ratios using the principle of water volume balance among rainfall amount, hydrologic losses, and runoff volume captured in and bypass flow overtopping the storage basin. For a regional study, this procedure can be applied to a range of basin sizes to produce the optimized design value for WQCV. The numerical algorithm used in the computer model offers both runoff volume capture and event capture ...