What is the Aquifer

Underground areas that hold enough water to provide a usable supply are called aquifers. Some of the largest aquifers in Texas, including the Ogallala and Gulf Coast, are composed of sand and gravel. In south central Texas, the San Antonio Segment of the Balcones Fault Zone Edwards Aquifer — commonly known as the Edwards Aquifer — is a karst aquifer, which means it consists of porous, honeycombed formations of limestone that serve as conduits through which water travels and is stored underground.