Edwards Aquifer Authority › Home - Edwards Aquifer Authority, The Edwards Aquifer Authority is a groundwater district, mandated by the 1993 Edwards Aquifer Authority Act. The Act grants all of the powers, rights, and privileges necessary to manage, conserve, preserve, and protect the aquifer. The EAA regulates the portion of the Balcones Fault Zone Edwards Aquifer – a jurisdictional area that provides water to over 2 million people, and covers more than 8,000 square miles across eight counties. These include all of Uvalde, Medina, and Bexar counties as wel.