Analyzing Low Impact Development Strategies Using Continuous Fully Distributed Coupled Groundwater and Surface Water Models

Abstract

Low impact development (LID) strategies have received attention in recent years as offering a potential way to mitigate the adverse effects of urbanization on hydrologic flow and water quality. The obvious benefits of reduced peak flows and the sizing of storm water ponds can be simulated in models such as USEPA's SWMM; however, the analysis of LID system interaction with the groundwater system is challenging. Addressing questions related to local infiltration capacity, feedback from the groundwater system (i.e. rejected recharge and saturation-excess runoff), and ecological benefits, including the preservation of baseflow and wetland hydroperiod, requires a spatially distributed and integrated analysis of the hydrologic system. The purpose of this chapter is to illustrate the challenges and insights that the authors have encountered while simulating and comparing the effectiveness and ecological benefits of different LID scenarios using an integrated groundwater and surface water model. Additional discussion addresses how this approach can be used to complement storm water modeling and provide for a complete analysis of LID functionality.

Discussion of “Low-Impact Development Effects on Aquifer Recharge Using Coupled Surface and Groundwater Models” by Eva W. Mooers, Rob C. Jamieson, Jenny L. Hayward, John Drage, and Craig B. Lake

“…As an example, the USGS Groundwater and Surface-Water FLOW model (GSFLOW) has been developed to simulate coupled flows of groundwater and surface water in one or more watersheds. Marchildon and Kassenaar (2013) conducted a modeling study in which they modified GSFLOW to successfully analyze different LID practices; however, some limitations have been encountered when using this model. HydroGeoSphere is another hydrological model based on physical principles and used to model variation in saturated groundwater transport and advectivedispersive solute transport in a discretely fractured porous medium.…”