Recharge enhancement and protection of a karst aquifer in central Texas

Abstract

The Edwards Aquifer in central Texas, like many aquifers in the world, is threatened by over exploitation and contamination due to rapidly increasing populations in the aquifer recharge and contributing zones. Close to 2 million people depend on the Edwards Aquifer as their sole source of drinking water. Studies have shown that under extreme drought conditions, many wells would go dry and springflows would drop to such low rates that endangered species that live in the springs would be jeopardized. To address these concerns, a concrete vault was constructed over Antioch Cave that is located in the channel of Onion Creek. Large amounts of water enter this cave when water is flowing in the creek. However, during periods of stormwater flow, the water contains varying amounts of sediment, bacteria, and other contaminants. A system was constructed over the cave entrance to keep the contaminated water from entering the cave. This system also increases the amount of good quality water entering the aquifer. Water levels in the aquifer and springflow rates can be maintained at higher amounts because of this increased recharge. This will help protect wells from going dry and will provide more springflow for the endangered species at the springs.