February Precipitation Improves Water Supply Outlook
BOISE- The March Water Supply Outlook Report just released by the Idaho Natural Resources Conservation Service has better news this month than last. According to the report February precipitation across the state ranged from above to well above average. The abundant mountain snowfall, along with cool temperatures to maintain the snowpack, provided a huge boost to this year’s water supply forecast.
“Some basins received more than twice their normal February precipitation,” said Ron Abramovich, Water Supply Specialist with Idaho Natural Resources Conservation Service. “The basins along Eastern Idaho’s continental divide still have the highest snowpacks in the state.”
The jet stream in February pushed storms into Idaho increasing snowpack levels across the state. Basins along the continental divide capitalized on the moisture with snowpacks that now range from 130 – 155% of normal.
Abramovich said the snowpack distribution this year is unusual with a large contrast from east to west. Typically the difference in snowpacksruns from north to south.
Because of February’s plentiful precipitation, streamflow forecasts improved from January’s dismal predictions. Abramovich said that to maintain the current streamflow forecast volumes, near normal or better snowfall is still needed until the season peaks in April along with cold mountain temperatures to keep the snow in the high country.
“Despite abundant precipitation, water supply shortages have not been eliminated in all of our basins,” Abramovich said. “Surface irrigation shortages will occur in the Owyhee basin and some shortages are still likely in the Big Wood, Little Wood, Big Lost, Little Lost, Oakley, and Salmon Falls basins.”
The streamflow forecast for most central Idaho streams is 40-60% of average in the Wood, Lost, Weiser basins, as well as basins from the Bruneau to the Bear River. The lowest projected flows are in the Owyhee Mountains and Camas Creek near Fairfield at only 20% of average. However, the important southern Idaho irrigation forecast for the Snake River near Heise is 120% of average.
As for which reservoirs around the state may fill, Abramovich says more analyses and discussions will take place this month. For details on snowpack, precipitation, streamflows, and reservoirs for each basin in Idaho, view the full March Water Supply Outlook Report online.