Colorado Basin Outlook Report March 1 2005

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COLORADO WATER SUPPLY OUTLOOK REPORT MARCH 1, 2005 Summary Snowfall during February was slightly below average across most of Colorado. As a result, there were slight decreases to snowpack percentages from last month's statistics. The state continues to have a large variability in snowpack percentages from north to south. At long last, drought relief is expected across most southern basins this spring and summer. Reservoir storage continues to improve slightly in many basins, and is the best shape since the spring of 2002. Water supply concerns for the 2005 water year are now focused on those basins across northern Colorado, where only 4 to 6 weeks remain in the snowpack accumulation season to recover from their current shortfalls. Without a wet spring in these basins drought impacts threaten to reappear. Snowpack Although drier, February's snowfall patterns were similar to those in January, where most storms entering the state brought the greatest moisture to southwestern Colorado. The Gunnison, Rio Grande, and combined San Juan, Animas, Dolores, and San Miguel basins continue to report snowpack percentages from 130% to 155% of average. Further east and north, snowpack percentages decrease significantly. Those basins reporting the lowest percent of average accumulations for March 1 include the South Platte and Yampa - White, which are only 80% and 84% of average, respectively. Statewide, snowpack totals are now 109% of average, and 122% of last year's readings. This month's statewide totals show a slight decrease in percentages from last month's 114% of average. At this point in the snow accumulation season, it seems unlikely that snowpack totals will reach average levels by season's end across northern Colorado. Meanwhile, snowpack totals across the southwestern basins reached their average seasonal maximum snowpack levels in early February, and by March 1 are about 110% to 120% of their average seasonal maximum water equivalent. In comparison to last year's snowpack on this date, all basins are reporting a greater average water equivalent than a year ago, except the Yampa and White basins, which are standing at 94% of last year. As expected, the Gunnison, Rio Grande, Arkansas, and combined San Juan, Animas, Dolores and San Miguel basins are all exceeding last year's snowpack by at least 30 %. This year's snowpack is just slightly better than last year's in the North and South Platte basins. Precipitation February brought much dryer conditions than January across Colorado. The Gunnison, Rio Grande and combined San Juan, Animas, Dolores, and San Miguel were the only basins reporting above average monthly totals, and those were only slightly above the average for the month. Other basins across the state received below average totals for February, and the driest basins were the Yampa and White at 75% of average, and the South Platte at 80% of average. Statewide, precipitation measured at SNOTEL sites was only 86% of average for the month. For the water year, which began on October 1, 2004, totals range from a high of 139% of average in the San Juan, Animas, Dolores, and San Miguel basins, to a low of only 851/o of average in the South Platte basin. For the state, the water year totals now stand at 108% of average.