Boise, ID, March 6, 2012 – The latest water supply outlook report released by the Natural Resources Conservation Service indicates good reservoir storage will offset this winter’s low precipitation levels. Snowpacks across the state range from 60 to 100% of average.
“This year there is a high degree of snowpack variability across the state,” said Ron Abramovich, Idaho NRCS Water Supply Specialist. “Northern Idaho drainages have near normal snowpacks while basins in southwest and central Idaho are in the range of 60-70% of average.”
Precipitation in February did little to increase mountain snowpacks until Leap Day storms on February 29 added a boost. February precipitation ranged from 38% of average in the Little Wood and Big Lost basins in central Idaho to 105% of average in northern Idaho.
“One or two months of below normal precipitation generally does not hurt the water supply too much, but when winter precipitation is lacking for three or more months then the impacts become more noticeable,” Abramovich said. “If the dry period extends through March, water users in central Idaho will want to watch the snowpack data to see how the water supply for this summer will be affected.”
Idaho’s reservoirs continue to be in excellent shape. This will help water users if snowpacks and summer streamflow runoff volumes end up below normal. Current stream flow forecasts call for only 25% of average runoff in the Owyhee basin in southwest Idaho to near normal streamflows in northern Idaho.
NRCS conducts snow surveys at the end of each month from December through May to make snow runoff predictions and water supply forecasts used in managing Idaho’s water resources.
For more information about snowpack, precipitation, runoff and water supplies for specific basins, please view the complete March 2012 Water Supply Outlook Report online at www.id.nrcs.usda.gov/snow and click on the ‘Water Supply’ link.