Assessment of Aquifer Storage and Recovery Feasibility using Numerical Modeling and Geospatial Analysis: Application in Louisiana

Aquifer storage and recovery (ASR) is a solution for regions experiencing groundwater shortages, but is unexplored in wet regions such as Louisiana, which is experiencing aquifer overdrafting at alarming rates. Surface storage reservoirs are infeasible in these low-gradient environments, so ASR can provide an alternative to alleviate groundwater stress and prevent subsidence and saltwater intrusion. The purpose of this study was to assess the feasibility of ASR in the Chicot Aquifer in Southwest Louisiana. The study is based on a regional groundwater model combined with a geospatial analysis of the quantity and quality of surface water and groundwater resources and land use. A statistical distribution was used to rate each criterion and combine them into a suitability index (SI) that defines each watershed’s feasibility considering combinations of criteria determined by the user’s purpose for ASR and the availability of data. The SI was formulated as a hybrid additive-multiplicative function to provide flexibility in specifying criteria that are deemed most constraining for ASR feasibility. The analysis identified the east-central zone of the Chicot Aquifer, which is experiencing substantial groundwater stress from agricultural irrigation, as most suited for ASR operations. Besides the criteria on water availability and aquifer characteristics, the quality of the surface water and land-use considerations were key factors in constraining the feasible watersheds