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' Basin Depletions ^ The District's annual water use is expected to increase from 6945 ac-ft to 28,589 ac-ft; however, average annual depletions will only increase from 4628 ac-ft to 7823 ac-ft due to the District's utilization of consumptive use (CU) transfer water and large return flows from ' the service area to the river. ^ Net average annual depletions to the Colorado River Basin will increase above historical levels by a maximum of 3195 ac-ft/yr at the end of the 50-year project life. This is in large part due to return flow credits for replacement reservoir being applied to the Reservoir instead of the Project Proponent. Effects on the 15-Mile Reach ^ ^ Flow reductions at the top of the 15-mile reach near Palisade, Colorado may range from -1 to +66 cfs and average +26 cfs. Flow reductions will average 0.4 to 3.1 percent of the monthly average flows and 1.0 percent of the average annual flow in the Colorado River at the top of the 15-mile reach. ^ Maximum flow reductions will occur during the months of November through August (averaging 24.0 to 34.5 cfs and minimum reductions will occur in September and October (averaging 12.6 to 18.7 cfs). ^ ^ Changes m water levels of the Colorado River at Palisade are expected to be less than 1 mch and average about 0.16 inches when the fu1150-year demand of the District is exercised; up until that time, the depth changes will be less. ' ^ USFWS flow recommendations are often not met under current conditions; under future conditions, that situation will not change. The USFWS flow recommendations will be met about 50 percent of the time in November through March, and never in April through October ^ Make-up flow requirements to meet USFWS target flows in the 15-mile reach exceed 1500 . ac-ft/yr when District demands reach the year 2006 projected level, exceed 3000 ac-ft/yr when demands reach the 20151eve1, and average 11,103 ac-ft/yr once demands reach the full 50-year demand in 2045. ^ ^ Reductions in water depth in preferred habitat areas in the 15-mile reach will typically range ' from 0 to 1 inch when the fu1150-year demand of the District is exercised; up until that time, they will be less. ' ^ Except for backwater habitat, suitable habitat depths are generally available for all habitat types both under current and future conditions during the winter and at least 50 percent of the time during the summer. i CDM Camp Dresser & McKee ' 0:8047-IIO~DOC~APpEND-B.DOC B-22