Project Overview

The goal of this project is to better characterize the quality of water discharging from Barton Springs. Variations in geochemical and physical parameters such as temperature, conductivity, pH, and major ion concentrations can help us interpret what is going on inside the aquifer. In addition, analysis of anthropogenic compounds such as pesticides, pharmacueticals, nutrients, and volatile organic compounds in spring water and in recharging creek water give us information both about the overall quality of water and the susceptibility of the system to contamination by different types of landuse. Barton Springs is home to the endangered Barton Springs Salamander and other endemic species, and feeds a 225-meter long pool enjoyed by over 340,000 people per year. Water quality assessment of the springs is key to the determination of the sustainablility of this precious resource.

The Barton Springs Aquifer

The Barton Springs segment of the Edwards Aquifer, located in southern Travis and northern Hays counties, is a karst ground-water system that provides vital water resources to the people of Austin and to endemic species, some of which are endangered. Karst groundwater systems in urban areas are especially vulnerable to contamination because of the rapid travel time of water from the surface into and through karst aquifers.



Water that flows out of Barton Springs began as rain that fell on the watersheds of the five creeks in the contributing zone of the Barton Springs Aquifer. Those creeks are (from north to south) Barton Creek, Williamson Creek, Slaughter Creek, Bear Creek and Onion Creek. Rainwater that runs across these watersheds and into the creeks flows in an easterly direction until it reaches the recharge zone, where a portion of the flow is captured by fractures, sinkholes and other karst features, enabling infiltration into the aquifer. Water the falls directly onto the recharge zone either infiltrates directly, flows into recharge features, or flows into the permeable creek beds. Water entering the aquifer via large openings such as fractures and sinkholes receives little filtration by soil or the rock matrix.








Once in the aquifer, water flows along preferential flow paths toward Barton Springs. The direction of flow is dictated by faulting along the Balcones Fault Zone, which is generally in a NE-SW direction. Most of the water eventually discharges from the Barton Springs system. The travel time varies depending on the point of recharge and the water level in the aquifer, but can be as rapid as several miles per day.

Data Collection