Ground-water resources of Colorado, Lavaca, and Wharton Counties, Texas

Abstract

The main sources of fresh water for all uses in Colorado, Lavaca, and Wharton Counties are the Chicot and Evangeline aquifers. The Jackson Group, Catahoula Sandstone, and Jasper aquifer are minor sources of water and are largely undeveloped in the area. The Chicot aquifer, which consists of discontinuous layers of sand and clay of about equal aggregate thickness, ranges in total thickness from 0 in the outcrop area to about 1,200 feet (366 m) in southern Wharton County. The Evangeline aquifer, which also consists of discontinuous sand and clay layers, ranges in total thickness from 0 at the outcrop to about 1,500 feet (457 m) in Wharton County. The combined thicknesses of the freshwater sands in the Chicot and Evangeline aquifers range from 0 at the outcrop to more than 850 feet (259 m) in Wharton County. Land-surface subsidence as a result of groundwater withdrawal is not a problem at this time. However, more data are needed to determine the extent of subsidence and the relationship between the amount of groundwater withdrawals and the amount of subsidence. The available data indicate that maximum subsidence within the three counties is less than 1 foot (0.3 in), and in most places is less than 0.5 foot (0.15 in).