114 CONSERVATION OF GROUND WATER 



shaped part of an aquifer at Miami, Okla., is cut off from the 

 rest of the aquifer. Pumping tests have demonstrated the 

 existence of similar barriers in parts of the limestone aquifers 

 of western Ohio. These geologic barriers are sometimes re- 

 sponsible for sharp decreases in yields of wells after they have 

 been pumped for a while. 



Miami, Okla. 4i Wells yield copious water supplies from 

 sandstone and limestone aquifers in northeast Oklahoma 

 and adjoining areas in Kansas and Missouri. In some parts 

 of the area, wells are so closely spaced that they have inter- 

 fered markedly with one another, and there are indications 

 of local "overdevelopment." On the other hand, these 

 aquifers are capable of transmitting large quantities of 

 water, as shown especially in several mines where millions 

 of gallons of water must be pumped out daily in order to 

 continue mining operations, and it is likely that large 

 quantities of water are still available for development by 

 properly spaced wells. 



At Miami a wedge-shaped portion of the water-bearing 

 Roubidoux sandstone is partly cut off from the rest of the 

 aquifer by the Seneca fault and the Miami trough, which 

 act as barriers to ground-water movement. Wells pumping 

 about 2 million gallons a day from the sandstone within this 

 wedge have created a cone of depression which expanded as 

 far as the barriers and could expand no farther. There has 

 been an accelerated decline in artesian pressure in recent 

 years. In a Miami city well that had flowed in 1907 the pres- 

 sure dropped at a rate of about 6 feet a year until 1937, 

 when it was 180 feet below the surface. In the following 10 

 years the pressure dropped 230 feet farther, at a rate of about 

 23 feet a year. The accelerated decline in water level since 

 1937 may be attributed in part to the effect of these barriers, 

 and in part to increased pumping from the aquifer. Current 

 pumping is undoubtedly greater than replenishment within 



** Reference: Schoff, S. L., "Ground-water Supplies and Uses in Oklahoma," 

 3rd Annual Wild Life Conference, June 1918. 



