156 CONSERVATION OF GROUND WATER 



of the valley. In the following decade replenishment was 

 greater than draft, and ground-water storage by 1948 was 

 about as great as in 1930. There are small areas of concen- 

 trated draft from wells, however, where water levels are now 

 more than 5 feet lower than in 1930. 



The ground water in a watercourse may have a significant 

 bearing upon administration of compacts that allocate usage 

 of water of interstate streams. As an example, the flow of the 

 Arkansas River from Colorado into Kansas is modified sub- 

 stantially by ground-water development. Although the Arkan- 

 sas River Compact of 1949 does not mention ground water, 

 its effective operation depends upon an adequate knowledge 

 of the ground-water hydrology of the watercourse in Colorado. 



Arkansas River Valley, Colo, and Kans.™ The Arkan- 

 sas River is outstanding in the extent to which the natu- 

 ral flow has been modified by development of both surface 

 water and ground water. The major water-producing area is 

 the headwaters area in the Rocky Mountains, and the plains 

 of eastern Colorado and western Kansas contribute rela- 

 tively small quantities to the river. Under present conditions 

 the river does not "hold its own" after it leaves the Rockies. 

 Generally, the flow is least in reaches near Garden City, 

 Kans., where the channel may be dry for weeks at a time in 

 the summer. The average annual flow at Garden City is 

 only about one-third of the runoff from the mountainous 

 headwater area, although the drainage basin is about eight 

 times as large. Downstream from Garden City the inflow 

 from tributaries and from ground water is so great that the 



79 References: Waite, H. A., Geology and Ground-water Resources of Ford 



County, Kansas, Kans. Geol. Survey Bull. 43, 1942, 250 pp. 

 McLaughlin, T. G., Geology and Ground-water Resources of 



Hamilton and Kearney Counties, Kansas, Kans. Geol. Survey 



Bull. 49, 1943, 220 pp. 

 Latta, B. F., Geology and Ground-water Resources of Finney 



and Gray Counties, Kansas, Kans. Geol. Survey Bull. 55, 



1944, 272 pp. 

 Frye, J. C, and V. C. Fishel, "Ground Water in Southwestern 



Kansas," Kansas Geol. Survey, 1949, 24 pp. 



