Water resources of the Upper Colorado River Basin - Technical report

Professional Paper 441

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This chapter contains an introduction and a summary.

The introduction gives background information on the area: geography, geology, physiography, climate, and stream regimen. Included is a table of hydrologic units, prepared by D. A. Phoenix, which separates the complex assortment of rocks according to generalized hydrologic properties.

The rest of the chapter summarizes the quantity and chemical quality of the surface water of the basin. There is a great deal of water which enters the basin annually as precipitation (92,739,000 acre-ft). Only a small part of this (2,257,500 acre-ft) is consumed by humans or is diverted out of the basin. The rest leaves the basin through outflow (12,733,100 acre-ft) or is lost by evaporation and plant transpiration (77,748,400 acre-ft).

The amount and chemical quality of the streamflow vary with time and place owing to both natural and human causes. To give a common base for comparing streamflow, an average was used which would have occurred if the level of upstream development existing in 1957 had existed throughout water years 1914-57.

Natural factors affect the streamflow and chemical quality: the amount of precipitation, the underlying soils, and the ground water. The human factor, however, greatly influences streamflow and chemical quality. Water quantity and quality are changed as the water is diverted for domestic, industrial, and agricultural uses. Domestic and industrial uses add 33,600 tons of dissolved solids annually to the streamflow; irrigation adds 3,446,700 tons. Water quality also depends on the proportion of individual constituents and the amount of suspended sediment.

Additional publication details

Publication type:
Publication Subtype:
USGS Numbered Series
Water resources of the Upper Colorado River Basin - Technical report
Series title:
Professional Paper
Series number:
Year Published:
U. S. Govt. Print. Off.,
Contributing office(s):
Alaska Science Center
370 p.