One of the responsibilities of the District is to determine the amount of available groundwater in the aquifers that can be used sustainably. The Aquifer Science Team evaluates and quantifies the sustainable yield of the Edwards and Trinity aquifers considering the critical, interrelated hydrogeologic factors of severe drought, pumping, spring flow, and water levels. One of the primary tools available to evaluate these complex and interrelated factors are groundwater flow models.

Most of the District’s current work has focused on the Barton Springs segment of the Edwards Aquifer; however, the District is now actively developing a sustainable yield model for the Trinity Aquifer—an increasingly targeted water supply within the District’s boundaries.