The Trinity Aquifer Runs Beneath McLennan County

The Trinity Aquifer lies under a wide stretch of Texas. Some parts take in water from the surface, while others sit below layers of rock. TWDB reports drops of about 350 to more than 1,000 feet along I-35 from McLennan to Grayson counties. City pumping caused most of the drop. The decline has slowed as cities use more lake and river water.

Before drilling a private well in McLennan County, call the Southern Trinity Groundwater Conservation District. The right form depends on the tract, what the water will be used for, and how much the well can pump. Even a well that does not need a permit may still need district forms.