Is the BSEACD’s Drought Trigger Methodology Representative of the Middle Trinity Aquifer?

Increased drilling and permit requests in the Middle Trinity Aquifer have highlighted the need for increased data collection and evaluation to better manage this limited resource. The purpose of this study is to evaluate the representativeness of the Barton Springs/Edwards Aquifer Conservation District’s (BSEACD) drought trigger methodology (DTM) for the Middle Trinity Aquifer, which relies on indices from the Edwards Aquifer. We reviewed available hydrologic data (streamflow, rainfall), regional drought indices (PHDI, US Drought Monitor), and Middle Trinity water-level elevations of the BSEACD and Hays Trinity Groundwater Conservation District (HTGCD) monitor wells for the period of 2008-2017. These data were compared and correlated to the current DTM used for all aquifers in the BSEACD. We conclude that the BSEACD drought indices reflect regional hydrologic responses to climatic events, and consequently have a good correlation to water levels within the Edwards and Middle Trinity Aquifers. It is our recommendation that the current DTM continue to function as the primary mechanism for making BSEACD drought declarations for all aquifers in the BSEACD