WSP05764 - Laserfiche WebLink

Home Browse Search

JiJJ225 -~- t' The irrigab1e lands of western Colorado are not extensive enough to require or demand even a considerable part of the total water sup- ply passing from Colorado, While there are approximately 25.000.000 acres of land in t he western thir d of Colorado in the Colorado Ri ver basin. probably not to exoeed 2.000.000 to 3.000.000 acres of this land wi 11 ever be irrigated. since there are vast areas of high plateaus, and mountains not suitable for oulti vation. There are also oonsider- able areas of fine land suitable for cultivation which will always remain unbroken because they are so located that there is no ndjaoent water supply. or the cost of construc~ing reservoire and canals to supply them will be excessive. " The menace that Colorado. New ~~xico. Utah, and Wyoming desire to avoid (in the construction of a large reservoir on the lower Colo- rado River) is the granting of a preferential or priority water right to such a reservoir that will ultimately be felt when these States attempt to irrigete the undeveloped arable lands within their borders. Just such water problems confront Colorado water users today in the San Luis Valley on the Rio Grande, in North Park on the North Platte, and in fuddle Park (transmountain diversion) on the headwaters of the Grand River, where rights of way over Government lands have been denied by the Interior Department without justification. Of a possible 2,000.000 acres that Colorado may ultimately irrigate from tributaries of the Colorado River, only 450,000 acres are now irri- gated. In comparison with this area the annual run-off or stream-flow of >;estern Colorado which passes noW unused across the State line is over 10,000.000 acre-fect after serving these lands, The total net demands or consumptive use of water for 2,OOO.Oqo acres will approxin,ate, and probably nct exceed, over 3,000,000 acre- feet. since ultimately large volumes of water used for irrigation return to the streams as seepage or return wat.r. Irrigation investigation. show that generally from 20 to 50 per cent of the water applied to land for irrigation ultimately returns -to the stream channel, This is well illustrated in the irrigation history of the North and South Platte Rivers, The annual measured return flow of the South Platte River in Colorado between La Salle and Ju1esburg, a distance of 150 miles, now amounts to 800.000 acre-feet annually. Reoords of return f10n secured in 1900 for the SDJ1le river section show the "ain ..t that time to have only been 3.'50,000 acre-feet, On the North Platte River, between Hhalen, \.jyoming and North Platte, Nebraska, the measured )'eturn now in 1918 amounted to approximately 400.000 acre-feet, and the records of the Reclamation Sorvice show that the 90.000 acres then under irrigation from the Interstate Canal were con- tributing 1. 5 acre-feet per nore per annum of return f10N water from irrigation to the various formerly dry tribub ries of the North Platte Ri ver.