Experimental and Modeling Study on The Performance of Low Impact Development: A Multi-Scale Study to Identify Enhanced Stormwater Control Measures

Stormwater management strategies such as Low Impact Development (LID) are control measures designed to restore the hydrologic flow regime and enhance the quality of stormwater. The performance of LIDs is highly variable and dependent of local conditions such as location and climate, and design characteristics such as filtration media. This study aims to assess the performance of LIDs through (1) a pilot-test study to examine the performance of different filtration media by conducting column experiments, (2) a field-scale study to assess the performance of different LID designs in a full-scale LID testbed, and (3) developing a stormwater model to further investigate its hydrological and treatment performance under different scenarios. The pilot test was designed to assess pollutant removal efficiencies of nine different filtration media. For the field study, the top three performing media of the pilot test were implemented in the LID testbed – composed of bioretention and sand filter basins - located atop the Edwards Aquifer's recharge zone. The LID testbed consists of six parallel cells filled with three LID designs in duplicates - with and without impermeable liner – to study the impact of direct infiltration on stormwater quantity and quality control. Lastly, we explored the near-optimal placement of LIDs within an urban watershed aiming to optimize their hydrological and treatment performance, by developing a many-objective simulation-optimization algorithm.