The Importance of Springflow

Traditionally, the Edwards Aquifer was viewed in isolation. Its rise and fall was seen as an indicator of whether San Antonio and its citizens would enjoy a water surplus, or suffer through a water shortage.

Today, we understand the Aquifer's significance as a regional water supply. The Edwards Aquifer has a direct impact on the surface waters of this region, including the Comal, San Marcos, and Guadalupe River system. Changes in the Aquifer's water supply can significantly alter this delicate balance.

Our State Legislature and courts have acted to protect this resource and all those who depend upon it. And yet, in the midst of a drought, the perception still exists that the only reason we should be worried about spring flow levels is because of the endangered species.

BUT, the Edwards Aquifer also supplies water to the Guadalupe River:

Spring flows contribute from 30% to 80% of the River's "base flow". In other words, without spring flow, the Guadalupe River would be 30% drier during normal times, and up to 80% drier during low rainfall and drought!

Most people who live downstream from the Comal and San Marcos Springs depend on the Guadalupe River for their basic water supply. This includes municipal, industrial and agricultural users who withdraw water from the Guadalupe River via state water rights and permits.

See the Edwards Aquifer and the Guadalupe River page to get a more detailed picture of the importance of Comal and San Marcos springflows to the entire Guadalupe River system.

© 1998 Guadalupe-Blanco River Authority