Nature

What Is the Edwards Aquifer?

By  | 

Unbeknownst to many in the Texas Hill Country, the ground beneath their feet holds the life of the area. The Edwards Aquifer literally is the life blood of the Hill Country. In fact, this area would not have grown to what it is today without the aquifer. Cities like San Antonio have long depended on the Edwards Aquifer for water, making it an integral part of the environment and geology of the region. But, it could be in trouble, and water supplies might be at risk in the future.

What is an Aquifer?

Edwards Aquifer and the Trinity River System

Photo: Wikimedia Commons

Aquifers trap water underground, like a natural cistern. But unlike a cistern, which is a hollow space, an aquifer has permeable rock, like limestone, to hold the water, like a sponge. The Edwards Aquifer ranks among the largest artesian aquifers in the world. Most regular aquifers simply hold the water, but an artesian aquifer, like the Edwards, holds water under positive pressure. This pressure gets relief through outlets such as the numerous springs in the Texas Hill Country, where the water forces itself out at the surface.

Springs

Comal Springs is One of the Many Outlets for Edwards Aquifer

Photo: Wikimedia Commons

Part of what makes the Hill Country unique is the abundance of naturally flowing, crystal-clear springs. San Marcos and Comal springs both get their water from the aquifer, but water is not the only thing that makes these springs unique. Rare species exist in and near these springs that you cannot find elsewhere. In fact, the U.S. Fish and Wildlife Services has declared these two springs to be the most ecologically diverse in the southeastern United States. Seven endangered species and one threatened species make their home in these springs. Preserving the Edwards Aquifer not only protects these plants and animals but it also helps to preserve drinking water for millions.

How Texans Use It

Edwards Aquifer Recharge and Catchment Areas
Photo: Wikimedia Commons

Page 1 of 2:12