Development of a Refined Conceptual and Numerical Model of the Edwards Aquifer, Texas

A project is underway to develop a refined conceptual and numerical groundwater flow model of the karstic Edwards Aquifer in central Texas. Since the development of the last groundwater model, significant advances have been made to better characterize the model domain of the Edwards Aquifer. This improved understanding of the model domain is incorporated into a refined conceptual model. Significant improvements include expansion of the model domain to include the contributing zone, refinement of boundary conditions, correlation analyses to quantify the relationship between recharge events and aquifer response, characterization and measurement of discharge mechanisms including paleo-stream underflow, development of a refined hydrostratigraphic framework model, fault and conduit characterization using tracer testing, and water-budget refinement. The refined conceptual model is incorporated into a numerical model that accommodates both conduit and diffuse flow. The ensuing numerical model is anticipated to provide a more representative simulator of groundwater flow in the regional-scale Edwards Aquifer.