said Todd Adams, Assistant Director with the Division of Water Resources.
Utah’s statewide total precipitation (at 77 Mountain Snotel Sites) for the 2009 water year will likely fall just short of the 30-year average, but is significantly higher than the past ten year average. In the past ten years only 1999, 2005 and 2006 were wetter.
The first three weeks of June were particularly wet and cold this year. June is not typically a month that contributes significantly to the season’s runoff and total reservoir storage. This year’s June precipitation, however, accomplished two things. It delayed reservoir withdrawals around the state, with many areas receiving adequate rainfall to meet crop’s consumptive requirements. Secondly, the cool wet conditions improved the efficiency of the runoff helping most of the State’s reservoirs to fill.
With efficient runoff and reduced irrigation demand Utah’s reservoirs have held up very well through the summer irrigation season. Statewide, Utah’s reservoirs are currently at about 67 percent of full. This is a much better statewide average, for this time of year, than Utah has experienced in the past ten years, and slightly higher than Utah’s long term average. Almost half of the 33 percent of unfilled storage capacity is in one reservoir: Bear Lake.
The northern portion of the State (including the Uinta Basin) has faired well this year. Bear Lake currently has approximately 170,000 acre-feet more water than it had at this time last year. This is an increase of 60 percent over last year’s storage at the end of September. Still, Bear Lake is well below full and will need several good water years to fill completely. All other reservoirs in the northern portion of the state have benefited from the wet June conditions and are in good shape.
The central and southern portions of the State have not benefited quite as well from the June rains as the northern part of the State. In the Sevier region, most reservoirs are slightly below their carry-over storage at the end of last year’s irrigation season, and significantly below their long term average. Most of the reservoirs in the southwest and southeast portions of the state are very close to last year’s end of the year supply, and very close to their long-term carry-over averages.