ABSTRACT

Ground-water mining of the Woodbine, Paluxy, and Trinity aquifers has led to substantial water-level declines in North-Central Texas since the turn of the century. Water-level maps constructed from R. T. Hill's 1901 well survey data show that water levels were initially above land surface before development. Numerous wells were drilled for water supply because the wells flowed at land surface. Water levels declined rapidly, and many of the wells around Fort Worth stopped flowing by 1914. Many of these wells were then abandoned, which slowed the rate of water-level decline. Since the turn of the century, water levels have declined nearly 850 ft in the Trinity aquifer in the Fort Worth area. As of 1990, water levels had declined about 400 ft in the Woodbine aquifer near Dallas and 450 ft in the Paluxy aquifer near Fort Worth. Maps drawn on the basis of water-level measurements in 1935, 1955, 1960, 1970, 1980, and 1990 show how the shape of potentiometric surfaces has evolved during the century.

This great drawdown in water levels has increased pumping costs, reversed ground-water flow directions in the Dallas-Fort Worth and Sherman areas, and may have affected water quality. Land subsidence from water-level decline has not been observed in North-Central Texas, perhaps because of the structural stability of the geologic units or a consolidation time lag. Pumping costs and water-quality problems have caused many ground-water users to switch to surface sources of water. Consequently, the rate of water-level decline has decreased in some parts of the aquifers, and in the case of the Paluxy aquifer, this may have caused recent water-level recovery.