The Edwards Aquifer: The Past, Present, and Future of a Vital Water Resource
CONTAINS OPEN ACCESS

The Edwards aquifer system is one of the great karstic aquifer systems of the world. It supplies water for more than 2 million people and for agricultural, municipal, industrial, and recreational uses. The Edwards (Balcones Fault Zone) Aquifer in the San Antonio, Texas, area was the first to be designated a sole source aquifer by the Environmental Protection Agency in 1975. The Edwards Aquifer also hosts unique groundwater, cave, and spring ecosystems. This 27-chapter memoir reviews the current state of knowledge, current and emerging challenges to wise use of the aquifer system, and some of the technologies that must be adopted to address these challenges.
The Edwards-Trinity (Plateau) and Trinity (Hill Country) Aquifer System, Texas Available to Purchase
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Published:September 10, 2019
ABSTRACT
The groundwater flow system composed of the Edwards-Trinity (Plateau) Aquifer and the Hill Country portion of the Trinity Aquifer together occupy an area of ~100,000 km2 of west-central Texas. In addition to the common groundwater flow system, these aquifers also share a common, contiguous hydrostratigraphy—the Trinity Group hydrostratigraphic unit. The aquifers provide the primary source of water for the Edwards Plateau and Texas Hill Country and also sustain numerous springs and streams in the region. The sensitivity of the aquifers to drought and well discharge has raised concerns over the availability of water from these aquifers.
Groundwater discharge takes the form of (1) discharge to streams and springs; (2) evapotranspiration; (3) pumpage from wells; and (4) cross-formational flow across the Balcones fault zone boundary to the Edwards (Balcones Fault Zone) Aquifer and underlying parts of the Trinity Aquifer. Groundwater inflow to these aquifers occurs by diffuse and discrete infiltration through the aquifer outcrops. Due to regional variability of lithologic compositions, hydraulic conductivity and storativity vary both vertically and laterally throughout the aquifer, with hydraulic conductivity decreasing with depth and from north to south.
- Colorado River basin
- Comanchean
- Cretaceous
- discharge
- drainage basins
- Edwards Aquifer
- Edwards Plateau
- evapotranspiration
- Fredericksburg Group
- ground water
- hydraulic conductivity
- hydrology
- hydrostratigraphy
- infiltration
- Lower Cretaceous
- Mesozoic
- potentiometric surface
- recharge
- Rio Grande
- storage coefficient
- Texas
- tributaries
- Trinity Aquifer
- Trinity Group
- United States
- Washita Group
- water wells
- Texas Hill Country