April's Cold Temperatures Delay Mountain Snowmelt

Streamflows remain low as do inflows into reservoirs due to cold temperatures keeping the snowpack intact according to the May Water Supply Outlook Report just released by the Natural Resources Conservation Service (NRCS).

“The current snowmelt rates are about a half an inch per day and the soil can absorb that,” said Ron Abramovich, Idaho NRCS Water Supply Specialist. “The high elevation snowpack hasn't started to melt yet due to the cool spring temperatures. But, the snowpacks are below their seasonal peaks so there is not a lot of snow up there to sustain streamflows.”

Basins south of the Snake River did receive above normal precipitation in April but not enough to improve the water supply for that area. The Idaho Surface Water Supply Index shows that water supply shortages are likely for irrigators in the Magic, Salmon Falls, Big Lost, and Little Lost River basins. Marginally adequate water supplies are expected for the Boise, Snake River and Oakley basins. Impacts to users in other basins will depend on how the water is used.

North Idaho received above average precipitation in April which brought the snowpack to near normal levels.

Abramovich recommends checking the May 2013 Water Supply Outlook Report on the NRCS Snow Survey web page www.id.nrcs.usda.gov/snow for detailed information on specific regions and basins. Also on the web page are links to daily summary reports, Snow Telemetry data, and snowmelt peak streamflow relationship information.

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.

The complete April 2013 Water Supply Outlook Report is available online at www.id.nrcs.usda.gov/snow and click on the ‘April 2013 Water Supply Outlook Report’ link. The report includes snowpack, precipitation, runoff, and water supply information for specific basins.

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.