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Show PART II PRESENT STATUS OF IRRIGATION Wyoming and Utah. The next largest acreage, 6l8,^OO acres or 38 percent, is in the Upper Main Stem Subregion, of which 98 percent is in Colorado. The remaining 18 percent of the irrigation development, comprising 290,800 acres, is in the San Juan-Colorado Subregion, of which 65 percent is in Colorado. Of the total acreage irrigated in 1965* 1,600,^-00 acres or 99 per- cent is irrigated entirely from surface flows. The remaining 1 percent, comprising 21,100 acres, is supplied partially or fully from ground water, Table 2 shows the breakdown of presently irrigated acreage from ground water. Table 2 - Area irrigated from ground (Unit--1,000 acres) water State Full use Partial usei/ Total Wyoming Utah Colorado 1.3 k.O 3.0 1.2 6.9 k.l 2.5 10.9 T.T Total 00 12.8 21.1 ~TJ Supplemental to surface supplies. Source: U.S. Census of Agriculture, 1959. Included in the total irrigated acreage of the region are 12l+,U00 acres of idle land which are not irrigated in an average year because of water shortage or for other reasons. Lands actually cropped and which utilize water for irrigation total 1,1*97,100 acres. Of this total 9^7,80O acres or 63 percent has a full water supply and 5^9>300 acres or 37 per- cent has a short supply. Water shortages, for the most part, occur dur- ing the summer months, as most irrigation is "by direct diversion from streams which recede after the spring runoff has passed. Supplemental late-season water is provided by reservoir storage. A total of about 308 reservoirs with an active capacity of 3,272,800 acre-feet, have been con- structed by Federal and non-Federal entities to provide storage regulation for irrigation in the Region, as of 1965. Only 9 percent of the irrigated land was provided supplemental water through reservoir storage by Federal projects in 1965* Some 80 percent of the irrigated acreage in the region produces al- falfa, grass hay, and pasture used to complement livestock grazing on the vastly larger areas of range and forest land. These crops are supple- mented by small grains and other annuals produced on the remaining irri- gated croplands. At lower elevations, such as in the vicinities of Mont- rose, Delta, Paonia, and Grand Junction, Colo., and Farmington, N. Mex., the farming is more diversified with fruits, vegetables, and feed crops produced. |