Land-Surface Subsidence in the Texas Coastal Region

Land-surface subsidence has been mapped in the Houston-Galveston area and is known to have occurred in other areas within the Texas coastal region. Most of the subsidence has been caused by both the withdrawal of ground water and by the production of oil, gas, and associated ground water. Land-surface subsidence was determined by comparing adjusted elevations of bench marks for various periods of releveling and by comparing topographic maps of the same areas for different years. In general, most of the Texas coastal region has subsided less than 0.5 foot (0.15 meter). The largest amount of subsidence measured in the region is in the Pasadena-Houston Ship Channel area, where the land surface subsided between 8.5 and 9.0 feet (2.6 and 2.7 meters) during 1906-73. The cause of the subsidence in this area was ground-water withdrawals