Laserfiche WebLink
<br />" -- <br /> <br />3468 <br /> <br />ANALYSIS OF THE COLORADO-BIG THOMPSON PROJECT OPERATION <br />WITH RESPECT TO EAST SLOPE DIVERSIONS <br />AND NON-CHARGE DELIVERIES <br /> <br />EXECUTIVE SUMMARY <br /> <br />This report describes and presents the results of an analysis for the Colorado River <br />Water Conservation District of certain issues associated with the operation of the Colorado-Big <br />Thompson (C-BT) Project during water years 1983-98. Specifically, the analysis was concerned <br />with C> the extent to which native Big Thompson River water was diverted and integrated into <br />the project water supply, (2) the extent to which Dan-charge water has been delivered to the <br />several streams in the NortKern Colorado Water Conservancy District service area and diverted <br />and used by the water users, and(Dthe ~ of these two aspects of the C-BT operation on <br />the flow in the Colorado River in the "15-Mile Reach", <br />,- <br /> <br />Initially, the layout and historical operation of the C-BT Project were studied, Then, three <br />EXCEL spreadsheets were developed and applied, The first was used to ,?stimate the water that <br />was available from the Big Thompson River under the C-BT Project water rights and to evaluate <br />the diversion of the non-charge water released to the Big Thomoson River, The second <br />- <br />spreadsheet was used to s.imulate the Adams Tunnel diversions and the ooeration of the east <br />slope project features under three different operational scenarios or runs, f3,un A corresponded <br />to the historical situation, It used historical diversions of Big Thompson River water, historical <br />, <br />deliveries of both charge and non-charge water to the water users, and average historical <br />storage contents for storage targets. Run B involved increased utilization of the Big Thompson <br />River water available under the C-BT Project decrees, historical deliveries of both charge and <br />non-charge water to the water users, and different storage targets designed to reserve storage <br />capacity in the reservoirs so that the Big Thompson River water could be diverted and made <br />part of the project water supply, ~n C involved increased utilization of the Bia Thompson River C\ <br />water, deliveries of onl charge water to the water users, and the same storage targets as Run ~' <br />- <br />B, The third spreadsheet simulated the operation of Granby Reservoir and calcu ated spills from <br />Granby Reservoir, flows in the 15-Mile Reach af the Colorado River, and the potential for <br />enhancement of soring peak flaws as required by the 1999 Programmatic Biological Opinion, <br />~ <br />which is currently under development as part of the Coordinated Facilities Operations Study, <br /> <br />The principal conclusions from our analysis are summarized in the following paragraphs: <br /> <br />1, <br /> <br />The C-BT Pro'ect did not make full use of its Big Thompson River water source during <br />1983-98, Our analysis indicated that an avera e of 21 862 acre-feet annuall of Big <br />Thompson River water could have be n diverted during this period, Most of this water, <br />an average of 18,331 acre-feet, was available in May and June, An average of not more <br /> <br />1 <br /> <br />LJ~,JB I <br />Iqrr ' <br />\ I ~ <br />,. <br />I <br />I <br /> <br />(j) <br /> <br />I, <br /> <br />'I <br />II <br />I' <br />I <br />I, <br /> <br />II <br />I', <br /> <br />@ <br /> <br /> <br />I' <br />9JbV [i <br />t I J pr~ ~: <br />l,71' ~Ill' !! <br />~~f 'i <br />\~lr;'(\." <br />, TII <br />lr 'I <br />