PROBLEMS FROM DEVELOPMENT 79 



of 50,000 acre-feet a year, chiefly from flowing wells, al- 

 though there are also a few pumped wells and several 

 springs. The use of surface water is considerably greater and 

 is approximately at the upper limit of permissible develop- 

 ment. Court decrees set the limits of use of water from the 

 tributaries, and the associated canal companies that use 

 water from Utah Lake lay claim to all water not used, as 

 well as to the return flow from users of the water in the 

 tributaries. 



Yet, although the surface water is generally regarded as 

 fully appropriated, and many believe that the ground water 

 should be similarly classified, there are large quantities of 

 water that leave the Utah Lake drainage basin unused. The 

 computed evaporation from the lake surface in nearly every 

 year is greater than the quantity taken from Utah Lake for 

 beneficial use. In 31 years (1916 to 1946 inclusive) the 

 average annual evaporation was estimated to be about 

 315,000 acre-feet, compared with pumped and gravity 

 diversions averaging 245,000 acre-feet a year. The evapora- 

 tion from land areas and transpiration by native vegetation 

 have not even been estimated, but it is certain that the total 

 in Utah Valley represents an additional natural loss of many 

 thousand acre-feet each year. 



The excessive natural losses of water in Utah Valley, and 

 particularly from Utah Lake, have long been recognized, 

 and several methods have been proposed for reducing them. 

 Some suggestions involve the concentration of Utah Lake 

 storage in a smaller area by diking off the shallower parts of 

 the lake. Storage in deep and narrow canyon reservoirs, 

 particularly in headwater areas, would be subject to less 

 evaporation loss than Utah Lake storage, but good addi- 

 tional reservoir sites are rare, and storage of anything like 

 the volume in Utah Lake could be achieved only at great 

 cost. 



As another alternative, it is quite possible that the 

 ground-water reservoir could be used to advantage in pro- 

 viding additional water for beneficial uses. If the artesian 



