Flow Control and Water Quality Treatment Performance of a Residential Low Impact Development Pilot Project in Western Washington

摘要

Washington State University and project partners implemented a flow monitoring project on a 3.35-hectare (8.27-acre) pilot project in western Washington (Meadow on the Hylebos) that incorporates low impact development (LID) stormwater management practices. LID practices used in the project design include bioretention swales, permeable concrete, compost amended soils, and surface flow dispersion. The primary goals of the monitoring effort are to evaluate the performance of individual LID practices and evaluate the effectiveness of integrating these practices into a stormwater management system. Continuous simulation modeling (Western Washington Hydrology Model) was used to assess peak flow and flow durations compared to stated flow control goals of the project. Flow rates for individual storms were assessed and water budgets developed that include surface and subsurface flow, infiltration and evapotranspiration in relation to precipitation inputs for bioretention swales and the project as a whole. Infiltration rates over time for the permeable concrete were also measured.