The Natural Resources Conservation Service in Idaho has released the January Water Supply Outlook Report, the first for the 2022 water year.
After some early season snowfall in October, snowpack remained alarmingly low until mid-December when winter storms and cold temperatures finally arrived. The second half of December brought significant increases in snow water equivalent (SWE) across the entire state. In addition, soil moisture content has increased across the state, which should help improve springtime runoff efficiency. Streamflow, snowpack, and precipitation data for each basin can be accessed on the NRCS Idaho Snow Survey web page.
“At this time, our primary concern for meeting irrigation demand this growing season is the low reservoir carryover storage that kicked off water year 2022,” said Corey Loveland, the new Supervisory Hydrologist for NRCS Snow Survey in Idaho, “Carryover storage was well below normal in all major reservoir systems across the region. Although reservoir storage continues to increase, we will need an above average snowpack to fill reservoirs this spring.”
January 1 streamflow forecasts generally reflect the current mountain snowpack and precipitation conditions – with above normal expected streamflow volumes for the April through July and April through September periods throughout much of central Idaho and extending to the Idaho Panhandle. Likewise, normal to slightly below normal streamflow volumes are forecast for the Upper Snake as well as most forecast points south of the Snake River. These early season forecasts should be approached with a degree of caution, as there are multiple months of unknown winter weather in front of us, which will directly impact future streamflow forecasts and spring and summer runoff.
For information on specific basins, streams, and reservoirs, please view the full report online at January Water Supply Outlook Report.