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<br />Projected Plan <br /> <br />For 1996 operations, three reservoir unregulated inflow <br />scenarios were developed and analyzed and are labeled as <br />probable maximum, most probable, and probable minimum. <br />The National Weather Service Extended Streamflow <br />Prediction (ESP) computer model uses current basin <br />conditions as well as historical data to predict the range of <br />possible future streamflows. Tbe ESP model was employed <br />to develop eacb inflow scenario, based on current soil <br />moisture conditions within tbe basin. Although there is a <br />wide confidence band associated with streamflow forecasts <br />made a year in advance, tbe data are valuable in analyzing <br />tbe possible impacts on project uses and purposes. Soil <br />moisture deficit conditions witbin the basin were eliminated <br />by the above normal snowpack that. was experienced in 1995. <br />This is expected to return the magnitude of inflows in water <br />year 1996 to normal conditions. Tberefore tbe magnitude of <br />inflows in eacb of the three inflow scenarios are near the <br />historical upper decile, mean, and lower decile (10 percent <br />exceedance, 50 percent exceedance, and 90 percent <br />exceedance, respectively) for eacb reservoir for water year <br />1996. <br /> <br />Based on the ESP model results, tbree different hydrologic <br />scenarios were developed for each reservoir. Tbe volume of <br />inflow resulting from these assumptions was used as input <br />into Reclamation's monthly reservoir simulation model. This <br />model is used to plan reservoir. operations for the upcoming <br />24-month period. Projected water year 1996 inflow and <br />September 30, 1995, reservoir storage conditioos were used <br />as input to this model and monthly releases were adjusted <br />until release and storage levels accomplisbed project <br />purposes and priorities. <br /> <br />Minimum instream flow levels bave been established at <br />several locations in the Upper Colorado River Basin which <br />are intended to preserve the aquatic resources downstream <br />of specific dams. The regulation of the Colorado River has <br />bad both positive and negative effects on aquatic resources. <br /> <br />Controlled cool water releases from dams have provided for <br />_ __ increased productivity of some aquatic resources and the <br />development of significant sport fisheries. However, the <br />same releases may be detrimental to endangered and other <br />native species of fishes. <br /> <br />Consultations with the Fish and Wildlife Service in <br />compliance with Section 7 of the Endangered Species Act <br />(Section 7 consultations) on the operation of the AspinaII <br />Unit on the Gunnison River, Navajo Dam on the San Juan <br />River, Flaming Gorge on the Green River and Glen Canyon <br />Dam on the Colorado River will continue in 1996. Studies <br />associated with these consultations will be used to better <br />understand the flow related needs of endangered and other <br />native species of fISh. AdditionaUy, interim flilw restrictions <br />on releases from Lake Powell will continue in water year <br />1996 until the corresponding Record of Decision on the Glen <br />Canyon Dam Environmental Impact Stateme.nt (GCDElS) <br />is completed. <br /> <br />Modifications to planned operations may be D1ade based on <br />changes in forecast conditions. However, due to the <br />Recovery Implementation Programs for Endangered Fish <br />Species in the Upper Colorado River Basin, Section 7 <br />consultations, and other downstream concerns, modification <br />to the monthly operation plans may not be based solely on <br />changes in slreamflow forecasts. Decisions on spring peak <br />releases and downstream habitat target flows may be made <br />midway through the runoff season. Reclamation and the <br />Fish and Wildlife Service will initiate roeetings with <br />interested parties, including representatives of the Basin <br />States, to facilitate the decisions necessary to finalize site <br />specific operations plans. All operations will be undertaken <br />subject to the primary water storage and delivery <br />requireroents established by "The Law of the River", <br />including Endangered Species Act compliance and other <br />applicable statutes. <br /> <br />There is a reasonable expectation that mainstem <br />consumptive use. in the Lower Division States will not exceed <br />9.25 billion cubic meters (7.5 million acre-feet) in 1996. ft <br />is therefore expected that aU reasonable beneficial <br />consumptive use needs of the Lower Colorado mainstem <br />users will be met in calendar year 1996. <br /> <br />4 <br />