Subsidence in Harris and Galveston Counties, Texas

The history of groundwater withdrawal in the Houston-Galveston area is reviewed, and impacts of subsidence are discussed. Pumping groundwater for industrial use began after World War I, and grew until 1975 when conservation efforts were instigated. However, between 1974 and 1978 groundwater use for public supply increased. As a result of the extensive pumpage, the pressure in the artesian aquifers has declined. The largest area of subsidence is in the vicinity of the Houston Ship Channel at Pasadena, Texas, but the area of active subsidence in the region is expanding. Permanent inundation and increased exposure to flooding are consequences of subsidence. In addition, well casings collapse, storm drains are less efficient, and geologic faults may have been activated. A Subsidence District was established to manage the region 's water resources. This District suffers because the regulations are difficult to initiate and because there is a lack of groundwater-use data. Projections indicate that subsidence will continue as an expense of growth. (Titus-FRC)