Water supply projections vary across Idaho
BOISE, Idaho (KIFI)-The Natural Resources Conservation Service reports most of Idaho now holds a normal to above normal snowpack.
February precipitation in the Upper Snake region ranged from 100% to 189% of normal, which increased total February precipitation for the water year by about 10%. As of March 1, the Henry’s Fork-Teton is 97% of normal, the Snake Basin above Palisades is 101% and the Willow-Blackfoot-Portneuf is 99% of average.
According to NRCS, the region reaches its peak snow-water-equivalent (SWE) on April 4. Currently, SWE is about 75%, so the region needs an 80% snowpack accumulation to reach a normal peak.
As of now, the 30-day forecast predicts an equal chance of above or below normal temperatures and lower than normal precipitation.
One of the most critical measurements is the Snake River near Heise. Right now, it is forecast at 91% of normal. With ample reservoir storage and near normal streamflow forecasts, water supplies are expected to be sufficient for Upper Snake water users this year.
The Lower-Middle Salmon sub-basin snowpack is the highest of Idaho’s sub-basins this month at 102% of normal. Taken together, NRCS says factors predict a fairly typical snowpack in the Salmon Basin with streamflow forecasts of 84% to 93% of average.
Further south, Bear Lake is 62% of capacity. Downstream users should have adequate water supply, but users relying on natural surface water still need above normal precipitation over the remainder of 2021 season.
The Wood and Lost River are expected to see well below normal streamflow. NRCS said water shortages appear to be likely for some water users in those areas this year.
