WSP11413 - Laserfiche WebLink

Home Browse Search

4. ~, The Ultimate Time Level was established by criteria as the end of the Bureau of Reclamation repayment period for the unit. This was established by assuming that the reservoir could be in operation by 1970; that a 5-year delay in commencement of repayment or development period would be needed and that the repayment period would be for 50 years. This gives an ultil]l8te time level of 2025. The intermediate and ultimate time levels bota assume Two Forks Reservoir in operation and are considered only in this manner. A number of detail studies were necessary to make up our ideal demand and storage study and we have some interesting charts to show later regarding this Ideal Demand and Storage Study. There are, however, certain conditions which must be explained before we consider the results of all these studies. These are outlined in Exhibit 4. Two Forks Reservoir or a similar facility was assumed to be in operation for all conditions. First we studied the 1990 level without a project, and with a project. Under the with project we have the alternate Weld County and Narrows conditions. Under each of these we have without reservoir replacement and with 'reservoir replacement. The with reservoir replacement consisted for the ,Weld County site of moving the Empire, Riverside and Bijou Reservoir storage space into Weld County Reservoir, and eliminating these three reservoirs. The with reservoir replacement for the Narrows site consisted only of eliminating Jackson Reservoir and transferring its space to the Narrows site. Under each of the with reservoir replacement conditions we have with and without added facilities upstream. These consist of facilities to use 15,000 acre-feet additional water at the 1990 level on lands served through the Burlington ditch and added facilities to enable the St. Vrain, Clear Creek, and Big Thompson to use 10 percent of their outflow when available. Our results are based on the precept that neither site would be built without including 'the reservoir replacement. The ,lower portion of Exhibit 4 shows the remaining basin shortages determined in each study. The historica;L basin shortages are 394,000 acre-feet; 153,000 above Weld County site, 49,000 between the sites and 192,000 below the Narrows site. With reservoir replacement at the two sites at the 1990 level, we have a remaining shortage of 144,000 acre-feet for Weld County and 153,000 for Narrows. These are shortages, so under this condition Weld County is 9,000 acre-feet better per year than Narrows. If we add facilities upstream to use more water in the tributaries, the remaintng shortages in the lower basin, of course, increase, and Weld County has remaining shortages of 175,000 acre-feet, while Narrows has remaining shortages of l87,000 acre-feet.