78 CONSERVATION OF GROUND WATER 



years has caused declining water tables and artesian pressures 

 and suggested the possibility of overdevelopment. State regu- 

 lating agencies have prohibited further development of some 

 ground-water reservoirs because of evidence over periods of 

 several years of declining artesian pressures. But the ground- 

 water reservoirs in this group have one characteristic in com- 

 mon, which is good evidence that recharge is at least as great 

 as present draft: all are still losing substantial quantities by 

 natural discharge either to streams or to areas of evapotrans- 

 piration. If there were sufficient knowledge about the natural 

 movement of water underground, it might be possible to in- 

 tercept some of that water and divert it to beneficial use with- 

 out infringing on established water rights. 



A few ground-water reservoirs discharge into fresh-water 

 lakes, of which Utah Lake is an example. The ground-water 

 reservoir of Utah Valley extends under the lake and provides 

 a substantial part of the inflow to the lake. In most of the 

 intermontane valleys of the West, ground water is discharged 

 by evapotranspiration, especially from moist playas or salt 

 flats, and from water-loving vegetation such as salt grass, greas- 

 wood, mesquite, salt cedar, willows, cottonwoods, and tules. 

 Willcox Basin in Arizona and Tooele Valley in Utah are 

 examples. 



Utah Valley, Utah. Zi Utah Valley, 25 to 75 miles south of 

 Salt Lake City, is fortunately situated where it can harvest 

 the water crop of tributary basins that drain parts of the 

 high and humid Wasatch and Uinta Ranges. So productive 

 are these drainage basins that the valley is exceptionally well 

 provided with water, and a surplus accumulates in Utah 

 Lake which is entirely appropriated for use in Jordan 

 Valley to the north. There has been practically no unused 

 outflow from Utah Lake to Great Salt lake since 1925. 



The use of ground water in Utah Valley is of the order 



2* Reference: Hunt, C. B., H. E. Thomas, and Helen Varnes, "The Bonne- 

 ville Basin, Part I, Northern Utah Valley," U.S. Geol. Sur- 

 vey rept., in preparation. 



