Stormwater runoff for selected watersheds in the Edwards Aquifer recharge zone, Bexar County, Texas, 1996-98

The Edwards aquifer is one of the most productive carbonate aquifers in the Nation. The dissolution-modified, faulted limestone aquifer is the sole source of public water supply for San Antonio, Texas (fig. 1) and is the major source of water for Bexar County. In addition to providing public water supply to more than 1 million people, the Edwards aquifer supplies large quantities of water for agriculture, industry, and military installations. Major springs discharging from the aquifer support recreational activities and businesses, provide water to downstream users, and provide habitat for several threatened or endangered species.