Laserfiche WebLink
<br />t, ,.,.]) () <br />utJ Ut ; (, <br /> <br />~19<' <br /> <br />Engineering Data <br /> <br />(1 <br /> <br />1. Discrep~ncies in b~sic data. D~ta concerning the flow of the <br />Colorado ni','Sr at Lee Ferry are presented in Appendix 1 by years for the <br />period l897~1943. These ccnsist of estimates by the Bureau of Reclamation <br />for the pe~iod l897~192l, and of records by the U. S. Geological Survey <br />for subsequen':; years. Coloracio notes that the U. S. Geological Survey has <br />also published estimates for the period l897~192l which differ in most <br />years, ~nd in some by substantial amounts, from the Bureau of Reclamation <br />estimates presented j.n the Report. Such discrepancie. in the basic data <br />repol'ted by' cooperating agenc:,es are confusing, and have required the <br />EI~ineering Committee of the Upper Colorado Rivor Basin Compact Commission <br />to undertake correlation studies and make its own estimations. <br /> <br />2. ~ral Conveyance Losses above Lee Ferry. The sOoocalled virgin <br />flow' of the Colorado Ri'ver at Lee Ferry w&s calculated in Appendix I, for <br />each year of the 1897~1943 pe,iod, as the sum of: (1) the actual flow as <br />estimated or reoorded, plus (2) tho quantity of water estimated to have <br />been oonsumed by the lands, irrigated within ths natural basin and to have <br />been diverted from the natural basin for use outside. Expressed as an <br />average for the period 1897~1943. the virgin flow of the Colorado River at <br />Lee Ferry, thus calculated, is reported at 16,270,000 acre feet annually. <br />With respect to the quantities of water estimated to have been utilized <br />upstream from Lee Ferry, attention has previously been directed to the fact <br />that the quantities employed in Appendix 1 (See l'&.rap'aph 5, "Detailed Views <br />and Recommendations" above) to calculate virgin flows differ from the <br />estimates of existing uses reported in the substantiating material. In <br />both estimates the evaluations were made as of projeot sites, _ the quantities <br />of water' consumed by the irrigation of le.nds wi thin the natural basin above <br />Lee Ferry being calculated by multiplying the number of aeres irrigated by a <br />unit rate of consumptive use considered to be applicable in accordanoe with <br />prevailing temperature$4 and the que.r.tities diverte~ from the natural basin <br />being J,ijeasu:,'ed at project sites. <br /> <br />, 0;, <br /> <br />f" <br /> <br />Colorado notes, however, that the Report, disregarding the natural <br />~hannel lo~ses incident to the conveyance of water downstream to Lee Ferry, <br />applies the full amount of the estimated upstream use., or the stream <br />depletions at project sites, to the flow at Lee Ferry. This erroneous <br />assumption of the Report, that water, if not used and oonsumed upstream, <br />would arrive in full amount at Lee Ferry, hac required the Engineering <br />Committee of the Upper Colorado River Basin Compaot Commission to undertake <br />studies and make estimations of natural conveyance losses along the Colorado, <br />Green and San Juan rivers and certain of their' tributaries above Lee Ferry, <br />partioularly in the States of Utah and New Mexiao. <br /> <br />30 S?grQe8'by.~:l!!ltes o.f $tream Flow. The Report presents no <br />information"conoerning' the sourQe~ by States of the flow' of the Colorado <br />River at Lee Ferry. This omissio~ of data, essential to determinations of <br />