220 CONSERVATION OF GROUND WATER 



although it is an essential factor also in water-distribution 

 systems. The use for power causes no deterioration in quality, 

 but it may sometimes be detrimental to the maximum utiliza- 

 tion of the water resources, chiefly because civilization has not 

 yet developed a means for large-scale storage of electric power. 

 Water for power is commonly stored in reservoirs catering also 

 to irrigation use, and the generation of power in the winter 

 requires removal from storage of water that might otherwise 

 be used during the following irrigation season. 



Anticipation of Future Requirements 



Whether surveyed by type of use or by region, present in- 

 formation indicates that the national need for water will con- 

 tinue to trend upward, possibly even at accelerated pace. Al- 

 most certainly the demand for water will increase at a greater 

 rate than the population. Considerably more water will be 

 required for public use to give everyone the standard of living 

 enjoyed by those who already have running water, bathtubs, 

 flush toilets, washing machines, and dishwashers. The garbage- 

 disposal unit is a recent development that will increase the 

 load on both water-supply and sewage-treatment facilities 

 when its use becomes widespread. These household items are 

 nonconsumptive users of water, and the water can be reused 

 after treatment. Home air-conditioning units of the type that 

 cool by evaporation (rather common in the arid Southwest) 

 are consumptive users and will help deplete the available 

 water supplies. 



The use of water for irrigation can be expected to increase 

 because of the Federal projects in the West which are bring- 

 ing water to new lands each year. In the humid regions, too, 

 supplemental irrigation to sustain crops during dry periods 

 has been so profitable that more and more acres are irrigated 

 each year; supplemental irrigation eventually may become 

 standard practice for many crops in the East, Middle West, 

 and South. On the other hand, there are several areas in 

 California, Arizona, New Mexico, Texas, and Utah where ir- 



