How large is Edward's Aquifer in Texas?
Edwards Aquifer
Located in South Central Texas, the Edwards Aquifer incorporates an area of approximately 4,350 square miles that extends into parts of 11 counties. The aquifer's boundaries begin at the groundwater divide in Kinney County, East of Brackettville, and extend Eastward through the San Antonio area and then Northeast where the aquifer boundary ends at the Leon River in Bell County. The aquifer is hydrologically separated into the Austin and San Antonio regions by a groundwater divide near the town of Kyle in Hays County.
Ogallala Aquifer
Large scale extraction for agricultural purposes started after World War II due partially to center pivot irrigation and to the adaptation of automotive engines for groundwater wells. Today about 27% of the irrigated land in the entire United States lies over the aquifer, which yields about 30% of the ground water used for irrigation in the United States. The aquifer is at risk for over-extraction and pollution. Since 1950, agricultural irrigation has reduced the saturated volume of the aquifer by an estimated 9%. Once depleted, the aquifer will take over 6,000 years to replenish naturally through rainfall.