Middle Trinity Aquifer Synoptic

BSEACD and HTGCD staff measure flow at Pleasant Valley Spring. They're standing in the river with a rock wall in the background.

Jeff Watson, Staff Hydrogeologist at BSEACD, measuring Pleasant Valley Spring flow on September 14, 2023 with Radu Boghici, Hydrogeologist at Hays Trinity GCD.

This month the District began conducting a synoptic survey of the Middle Trinity Aquifer. This involves measuring hundreds of Trinity Aquifer wells within a set timeframe and provides an overarching ‘snapshot’ of the aquifer’s groundwater levels and flow conditions during severe drought. This data will help the District and others understand how the Trinity Aquifer responds to drought and better manage Trinity groundwater resources. 

The Trinity Aquifer is an important natural resource and serves as the only available drinking water for many people in central and western Hays County. It is also the source for many springs in the Blanco River Basin, including Jacob’s Well, Pleasant Valley Spring, and Park Spring, which are ecologically, culturally, and economically significant to the region. As a result of recent rapid population growth, pumping from the Trinity Aquifer has increased and put a strain on this critical water resource.  

Several synoptics have been conducted on the Trinity Aquifer previously with the most recent one taking place in 2018. These surveys provide valuable information about the Trinity under varying drought and non-drought conditions. Collectively, this data will inform the District’s Trinity Sustainable Yield Study, which aims to better quantify groundwater resources for more effective management of the aquifer. 

2023’s synoptic is a collaborative effort between the District, Hays Trinity Groundwater Conservation District, and Edwards Aquifer Authority. Additionally, students from the University of Texas’ Department of Earth and Planetary Sciences collected measurements as a part of their Karst Hydrogeology Field Methods class. The District is appreciative of all these organizations’ participation in this study. 

Jacob Newton, Regulatory Compliance Specialist, measuring a Middle Trinity Aquifer well on September 21, 2023.