Groundwater Data

The District has been dedicated to establishing good sound groundwater and geologic data for the area.  The Hill Country of Texas and Burnet County in particular has some of the most diverse geology and hydrology in the United States.  The District is on the Eastern edge of the Llano uplift, a structural anomaly that has exposed ancient Precambrian rock in the midst of the younger Cretaceous aged Edwards Plateau.  This complicated geologic event has created multiple aquifers that only exist in areas surrounding the LLano uplift.  There exists numerous faults that can greatly alter the hydrogeology of the area and creates very unique hydrology situations.   The available groundwater data for the area is very limited, therefore the District is at the forefront for gathering data that will help manage the precious resource for years to come.


Our District has one major aquifer(Trinity), three minor aquifers(Ellenburger-San Saba, Marble Falls, Hickory) and at least two additional local water bearing formations(Granite, Granite Gravel).  Descriptions and Maps of all the aquifers in the District can be found on the Aquifers page.

Monitor Well Network

The District has identified the development of groundwater monitoring well networks for the various aquifers within the District as a top priority project. 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. The proposed plan will establishapproximately 50 wells throughout the District.   The District monitoring well plan is a “state of the art” project.  To view the monitor wells visit the Monitor Well Network page.

Geophysical Logging

Geophysical logging is a method to gather geologic data from logging the borehole of the well with specialized equipment.  Geophysical logging has been around in the oil field for many years, but more recently it has been used by groundwater experts to record valuable geologic data.  The complicated geology of the Llano uplift area emphasizes the need to use geophysical logging as a tool to develop more information about the regions aquifers.  Visit the Geophysical Logging page for more info.

Rainfall Maps

The District aquifers all have an outcrop area, area where the aquifer formation is on or close to the surface, that recieve recharge during rain events.  The amount of water that is recharged into the aquifer from rainfall can be estimated but is never exact.  Rainfall data can help to better estimate the percentage of rainfall that does get to the aquifer.  The District creates its own rainfall maps using GIS and data from the National Weather Service.  Visit the Rainfall Maps page for more info.