January precipitation was below normal across most of Idaho according to the latest water supply outlook report released last week by Natural Resources Conservation Service (NRCS). The report shows the snowpack decreased by up to 30 percentage points from a month ago.
“If February is dry, the snowpack and streamflow percentages will decrease like they did in January,” said Ron Abramovich, NRCS Water Supply Specialist. “That could affect the water supply this summer.”
Currently, the snowpack ranges from a low of 75% to 128% of normal. Low elevation snowpacks that were below normal last month are still well below normal while higher elevation snow is in better shape and maintaining higher percentages.
“Most basins started the season with good soil moisture and snowpack conditions,” said Abramovich. “We’ve learned from the past that we can usually get by with one month of below normal precipitation, especially after a good start like this year. When we get two dry months in a row, negative impacts on the water supply start to occur.”
The report also shows streamflow forecasts decreased across most of the state, matching snowpack declines. Reservoir storage south of the Snake River is below average due to below normal runoff in 2012. However, elsewhere across the state reservoir storage is near average or above.
For more information about snowpack, precipitation, runoff, and water supplies for specific basins, please view the complete February 2013 Water Supply Outlook Report online at www.id.nrcs.usda.gov/snow and click on the ‘Water Supply’ link.
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.