PROBLEMS FROM DEVELOPMENT 103 



decline. There was no evidence of decline of water table in 

 the outcrop area, however. 



The history of the development of the Dakota sandstone, 

 therefore, is one of large initial yields from storage under- 

 ground and progressive diminution in yield to a level de- 

 termined by the transmission capacity of the aquifer. The 

 conclusions from the studies at Ellendale were that water 

 moves eastward in each 1-mile width of the aquifer at a rate 

 of less than 100 gallons per minute. By 1938 the discharge 

 from wells was only slightly greater than this amount, and 

 conditions were approaching equilibrium. 



The unbridled development of this reservoir was accom- 

 panied by prodigal waste of water taken almost entirely from 

 storage within the reservoir. Compared with the great quan- 

 tities discharged by wells in the past, the rate at which water 

 can move eastward from the recharge area is very low. The 

 annual draft from all wells in the reservoir is probably still 

 declining slowly and will eventually reach a rate set by this 

 transmission capability — a quantity which the reservoir can 

 supply perennially to wells. Husbanding of the tremendous 

 initial storage and artesian pressures in the aquifer would 

 not have increased this ultimate yield. However, preven- 

 tion of waste would have permitted withdrawal from stor- 

 age over more extended periods and under greater artesian 

 pressures. 



There are very few ground-water reservoirs in which fresh 

 water is known to have traveled as much as 100 miles from 

 the recharge area, and most commonly the travel of water in 

 artesian aquifers is 50 miles or less. The Dakota sandstone is 

 thus exceptional. More typical are the deep sandstone aquifers 

 of the Middle West from which some wells draw water that 

 has traveled more than 80 miles from the recharge area. In 

 the Chicago-Milwaukee area, heavy industrial draft has low- 

 ered the artesian-pressure surface more than 100 feet in an 

 area of more than 2,500 square miles. 



