Subsidence in the Houston-Galveston region: a comprehensive analysis

Low cost has led to steadily increasing withdrawals of ground water in the Houston-Galveston region with a resultant decline in artesian pressures in the region's aquifers. Artesian pressure provides hydraulic buoyant support for compressible clay layers within the region's aquifers, and the declines in pressure brought about by heavy, concentrated pumping have reduced this support, causing compaction of the clays, manifested by land surface subsidence of from .5 to 8.5 feet over a 47 square mile area by 1973. This subsidence threatens lives with flooding and is responsible for property damage of hundreds of millions of dollars. Such consequences outweigh the economic benefits of ground water withdrawals. Alternatives exist; an expanding regional data base on subsidence and pressure declines makes possible a determination of the optimal spacing and production pattern to obtain the maximum safe ground water yield without causing unacceptable subsidence. Current studies recommend a reduction in pumping in some areas with an ultimate regional (66 square miles) safe yield of 49-7 mgd which will be exceeded by demands before 198. Water from the Brazos, San Jacinto, and Trinity Rivers can meet demands beyond the year 2, but at a much higher price than that for ground water. Uncertainty in the common law and inadequate statutory laws have delayed efforts to control ground water withdrawals causing subsidence. The uncertainty in the common law will be resolved in 1978 by the case of Friendswood Dev. Co. v. Smith-Southwest Industries, 546 S.W.2d 85, an appeal to the Texas Supreme Court of an appellate court ruling that shifts the cost of subsidence from the victim to the ground water user by allowing recovery for subsidence damages caused by negligently conducted ground water withdrawals. Previous Texas cases have consistently refused to restrict ground water use in water rights disputes. In 1975 the legislatively created Harris-Galveston Coastal Subsidence District began to regulate ground water withdrawals in the two county area in order to prevent any further subsidence that causes flooding within the District. The District's primary regulatory tool is the authority to enforce well spacing and production restrictions through a permitting procedure based on a comprehensive district plan for controlling subsidence. The constitutionality of the District and its efforts have been appealed to the Texas Supreme Court, after favorable review in the lower courts, in the case of Beckendorff v. Harris-Galveston Coastal Subsidence