Coupled Water Balance and Groundwater Model to Assess the Influence of Low Impact Development Stormwater Strategies on Groundwater Recharge.

Abstract

Low impact development has been adopted as a sustainable way of managing stormwater in urbanized catchments. While the effect of LID features on surface water and stream health has been investigated in recent studies, less is known regarding the effect on groundwater recharge. The hydrologic model PCSWMM was coupled with the groundwater model, MODFLOW to assess the influence of LID on groundwater recharge. The coupled models were calibrated and validated using pre-development stream flows and monitored groundwater levels from a predominately forested catchment in which residential development has since taken place. PCSWMM was used to quantify net infiltration rates for conventional and LID stormwater practices. Net infiltration rates were coupled with MODFLOW, which was used to determine aquifer recharge and the availability of the groundwater aquifer to supply the residential development by mean of individual drilled wells. Development was found to decrease net infiltration, and results demonstrated that LID can enhance infiltration.