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<br />the decline of two key resources in the Grand Canyon; sediment and population viability of <br />endangered humpback chub. The Finding of No Significant Impact on the experimental flows can be <br />found at http://www.uc.usbr.gov/amp/flow_fonsi.pdf. <br /> <br />Upper Colorado River Basin Hydrology <br /> <br />The month of March pretty much dashed hopes that 2004 would bring relief to the ongoing drought <br />in the Colorado River Basin. Basin snowpack on March 1,2004 was 96 percent of average. At that <br />time the April through July inflow was forecasted to be 82 percent of average. The weather pattern <br />in March, 2004 was very dry and extremely warm for early spring. Temperatures around the basin <br />for much ofthe month were 20 degrees above average. As of April 7, 2004 snowpack in the basin <br />has fallen to 6:'5 pf(rcent of average..-a drop over 30 percentage points in just one month. The low <br />elevation snow (below 6,000 feet) in the basin is now gone and much ofthe mid-elevation snow <br />(6,000 to 9,000 feet) has melted out as well. While river flows increased in late March and early <br />April, these increases are not nearly enough to offset the early season loss of snow and the <br />possibility of better runoff conditions in May and June. The National Weather Service March final <br />forecast is calling for 4.0 million acre-feet of unregulated inflow to Lake Powell during the April <br />thrOugh July runoff period. only 50 percent of avera,ge. This is a sizable reduction from the volume <br />forecasted only a month ago. The temperature pattern in April remains above average. There have <br />been several precipitation events, primarily in the southern portions ofthe basin so far in April, <br />however. <br /> <br />So, the drought continues. The Colorado River Basin is now in its 5th year of drought. Inflow <br />volumes have been below average for 4 consecutive years, with 2004 almost certain to follow suit. <br />Unregulated inflow in water year 2003 was only 53 percent of average. Unregulated inflow in 2000, <br />2001 and 2002 was 62, 59, and 25 percent of average, respectively. Inflow in 2002 was the lowest <br />ever observed since the completion of Glen Canyon Dam in 1963. <br /> <br />Inflow to Lake Powell in March 2004 picked up as the abnormally warm and dry weather pattern <br />melted out significant amounts of snow in the basin. Even so, March inflow ended up below normal. <br />Unregulated inflow in March was 538,000 acre-feet, 81 percent of average. A large portion of the- <br />melting snow last month was absorbed by the dry soils in the basin. As of April 6, 2004 inflow <br />to Lake Powell is 11,700 cfs about 97 percent of what is normally seen in early April. It should be <br />noted that the snow is melting out much earlier than average this year and the flows we are seeing <br />now are likely at the expense flows in May, June and July. <br /> <br />Low inflows the past 5 years have reduced water storage in Lake Powell. The current elevation (as <br />of April 7, 2004) of Lake Powell is 3,:'5R1 feet (117 feet from full pool). Current stora,ge is 10.2 <br />million acre-feet (42 percent oflive capacity). <br /> <br />The water surface elevation of Lake Powell is at its seasonal low. The water surface elevation will <br />likely increase in April, May and early June. Under the current inflow forecast, Lake Powell is <br />projected to reach an early summer peak elevation of3,590 feet, probably in mid-June. <br />