PROBLEMS FROM DEVELOPMENT 115 



this wedge because of these barriers, but there is additional 

 water available for development outside the wedge-shaped 

 area. 



In relation to quantity of water pumped, the greatest de- 

 clines of water table or artesian pressure occur generally in 

 ground-water reservoirs with the poorest capabilities for trans- 

 mission of water. As an example, Dickinson in western North 

 Dakota meets its water requirements (600,000 gallons per day) 

 with difficulty by pumping from wells in a poorly permeable 

 sandstone. Pumping from seven wells had lowered the water 

 table more than 80 feet by 1943, and the yield dropped so that 

 it was necessary to restrict the use of water. There was very 

 little change in water levels, however, from 1943 to 1947, and 

 it appears that the rate of movement toward the wells in recent 

 years has been approximately equivalent to the pumpage. 

 As another example, sandstone aquifers of low permeability 

 are pumped heavily at Dallas and Fort Worth, Tex. 



Dallas and Fort Worth, Tex. 45 About 16 million gallons a 

 day is pumped from wells for industrial use at Dallas and 

 Fort Worth, and in addition about 18 million gallons a day 

 is pumped for public use from the same aquifers to the north 

 and south. The water in these aquifers was originally under 

 sufficient artesian pressure to flow at the surface, but pump- 

 ing has lowered the water levels as much as 500 feet in the 

 business district of Fort Worth, and nearly 300 feet at Dal- 

 las. The recharge area is 20 to 40 miles west of Fort Worth. 

 The aquifers have low permeability and consequently 

 limited ability to transmit water, with the result that large 

 declines in artesian pressure have occurred in all localities 

 where the draft on underground reservoirs has been heavy. 



The total water requirements of the Dallas-Fort Worth 

 area are far beyond the capabilities of the ground-water 



45 Reference: "Water Facts in Relation to a National Water Resources 

 Policy," U.S. Geol. Survey, Mimeo. rept., Appendix C, p. 

 112, April 1950. 



