Optimal Number and Location of BMPs for Stormwater Management

Abstract

A distributed hydrologic model of an urban watershed in the northeast U.S. was developed and combined with a genetic algorithm (GA) to determine the optimal number and location infiltration-based best management practices (BMPs) for stormwater management. The distributed, event-based hydrologic model integrates the Curve Number method with a hydrologic network model of the catchment using a system of 4,533 hydrologic response units (HRUs). BMPs were conceptualized as elements that alter the infiltration/runoff partitioning of the HRUs to which they were applied. The results indicate that the optimal location and number of BMPs is a complex function of watershed network connectivity, land-use, distance to channel and contributing area, requiring an optimization approach of the type introduced here. A Pareto frontier describing the tradeoff between the number of BMPs, representing project cost, and watershed flooding is developed.