AQUIFER INFORMATION
Trinity aquifer
The Trinity Aquifer is a major aquifer that extends across much of the central and northeastern part of the state. It is composed of several smaller aquifers contained within the Trinity Group. Although referred to differently in different parts of the state, they include the Antlers, Glen Rose, Paluxy, Twin Mountains, Travis Peak, Hensell, and Hosston aquifers. These aquifers consist of limestones, sands, clays, gravels, and conglomerates. Their combined freshwater saturated thickness averages about 600 feet in North Texas and about 1,900 feet in Central Texas. The aquifer is one of the most extensive and highly used groundwater resources in Texas. Although its primary use is for municipalities, it is also used for irrigation, livestock, and other domestic purposes.
hickory aquifer
The Hickory Aquifer is a minor aquifer that lies under 19 counties of Central Texas. Llano, Texas, lies at its heart. This part of the Texas Hill Country is home to the noted Llano Uplift, a circular geological granite dome dating back to the Precambrian age (from 550 million to 4 billion years ago). The Hickory Aquifer is a mixture of terrestrial and marine sandstones, siltstones and mudstones.
The Llano Uplift is among the oldest rock found in Texas. The Uplift itself is surrounded by younger layers of sandstone and other forms of rock. Hickory Sandstone sits on top of the Precambrian rock that is part of the Uplift. It can be seen as outcrops at various points around the dome before sloping away and following the dome’s slope deep into the Earth. That sandstone is the core that makes up the Aquifer.
ellenburger aquifer
The Ellenburger−San Saba Aquifer is a minor aquifer that is found in parts of 15 counties in the Llano Uplift area of Central Texas. Water is held in fractures, cavities, and solution channels and is commonly under confined conditions. The aquifer is highly permeable in places, as indicated by wells that yield as much as 1 ,000 gallons per minute and springs that issue from the aquifer, maintaining the base flow of streams in the area. Water produced from the aquifer is inherently hard and usually has less than 1 ,000 milligrams per liter of total dissolved solids
Geological Cross Section: Stonewall, TX to San Marcos, TX, June 2019
Trinity Aquifer DFC Compliance Analysis for Blanco County
MONITOR WELL PROGRAM
The monitor well network is used for monitoring the water level changes to assess the current conditions of the aquifer and to record long term changes for better management and planning. District personnel visit each monitor well site regularly and record the water level for that well.
District Office Monitor Well
The District’s Ellenburger monitor well, located at the District office at 601 W. Main, is now outfitted with satellite linked telemetry which will provide publicly available up to date water level readings. Daily data is available to view at the following link.