Land-surface subsidence characterizes much of the Texas Coastal Zone, but is most common in the upper part of the Zone and especially in the greater Houston area. The degree of subsidence ranges from acute to that discernible only with precise instrument leveling. A number of factors can result in surface subsidence; however, the major cause in affected portions of the Texas Coastal Zone is the lowering of pressure heads due to the withdrawal of ground water. In local areas, subsidence has also been a function of the removal of oil and gas, and the solution mining of sulfur and salt. Other causes, significant in other areas, are insignificant in the Texas Coastal Zone.Bureau of Economic Geolog
