MANAGING GROUNDWATER RESOURCES USING INTERACTIVE 3-D HYDRO-STRATIGRAPHIC MODELS IN TEXAS

The geology controls the groundwater. Understanding the spatial variability of the aquifer’s lithology, stratigraphy, facies changes, faulting and other subsurface structures is critical to managing groundwater resources. Geologists seldom make groundwater management decisions; therefore, it is critical that decision makers are enabled to make informed, science-based decisions. A simple, visually-oriented, three-dimensional (3-D) interactive hydro-stratigraphic platform can enhance future management of groundwater in Texas.

The creation of high-resolution, interactive, 3-D hydro-stratigraphic county-scale models to manage and protect groundwater resources in Texas has been the focus of a team of consultants in Austin, Texas. The team has successfully built interactive 3-D models of four large (> 1,000 mi²) groundwater conservation districts, portions of 12 West Texas counties in the Permian Basin for the University Lands (oil revenue for Texas Universities) and the brackish groundwater of the Blaine Aquifer (15 counties) for the Texas Water Development Board (TWDB). The West Texas 3D models include numerous water, oil and gas formation top surfaces down to 23,000 feet, and typical well densities for the 3D models range from 500 to over 1,000 water, oil and/or gas wells per county.

The Leapfrog 3-D model software tools efficiently incorporate borehole data or logs, GIS datasets, georeferenced images of historic maps, water-levels, geochemical data and contacts between geologic units. The 3-D models are well-documented, dynamic and quickly updated. These 3-D geologic models allow anyone to instantly understand the architecture of the aquifer. End users with basic computer skills can slice the 3-D model along any plane to generate cross sections, fade or turn off geological formations, measure formation thickness or depths from land surface, look at well attributes, investigate saturated net sand distribution and/or continuity, investigate cavities, view water levels or chemistry with time and/or depth and calculate aquifer volumes.