Laserfiche WebLink
<br />t"- <br />oo <br /> <br />(...: <br /> <br />-- <br /> <br />The analytical water supply studies for determining the project <br />water requirements account for diversions of all active ditches, in- <br />oluding Rabbit Ditch, but do not inolude the inchoate rights of the <br />unirrigated Indian lands. <br /> <br />c <br /> <br />It will be necessary that the plans of the Indian Service be for- v <br />mulated before the project goes to construction, not only to clear <br />title to reservoir right-of-way, but to prevent extensive future read- <br />justments in water supply. <br /> <br />Available Water Supply - Colorado Division <br /> <br />Practically the entire supply for the lands irrigated at present <br />is represented by the run-off of La Plata River at Hesperus, where a <br />continuous record of streamflow has been maintained since May 19l7. <br />This atation is near the margin of the La Plata Mountains and at the <br />upper end of the irrigated area in Colorado. Three ditches divert <br />water from the river above the station for the irrigation of 3,000 <br />acres of land, the average yearly diversion being 3,400 acre-feet. <br /> <br />The mean annual run-off at the Hesperus station was 35,500 acre- <br />feet for the period of record, varying from a minimum of 13,900 acre- <br />feet in 1934 to a maximum of 65,500 acre-feet in 1941. The yearly <br />supply varies 'greatly and even the mean run-off is inadequate for <br />19,140 acres, the maximum irrigated since 1930. In dry years, like <br />1931 and 1934, the flow at Hesperus is less than one acre-foot per acre <br />irrigated. <br /> <br />The flow at Hesperus is not all available for diversion by Colorado <br />ditches, since a portion of the Hesperus flow must be passed downstream <br />to New Mexico, in accordance with the terms of the La Plata River Compact. <br /> <br />During the irrigation period of April to October, La Plata River <br />flow diverges widely from monthly irrigation relluirements, as shown in <br />the following tabulation: <br /> <br />Distribution of Run-off, La Plata River at Hesperus, Colorado <br /> <br /> Average Run-off, <br />Month 1918 to 1942, inclusive <br /> Acre-Foet Percent <br />April 5;700 18 <br />May 12 , 100 37 <br />June 8,100 25 <br />July 2,400 7 <br />August 1,500 5 <br />September 1,600 5 <br />October 1,100 3 <br />Total 32,500 100 <br /> <br />Ideal <br />Irrigation <br />demand <br />Percent <br /> <br />4 <br />14 <br />24 <br />22 <br />21 <br />11 <br />4 <br /> <br />100 <br /> <br />20 <br />