2021 Water Year
This spring has continued to be exceptionally dry with well below normal precipitation across Idaho. A few storms during April brought minimal snowpack (SWE) increases to the highest elevation sites, but overall, this frozen water resource is transitioning to its liquid form. Throughout Idaho, the snowpack is melting earlier and more quickly compared to the historical average. Peak snowpack occurred up to 26 days earlier than normal at some sites.
“Based on dry soil conditions and lack of spring precipitation, we expect continued water supply shortages in the Big Wood, Little Wood, Big Lost, Little Lost basins.” said Erin Whorton, Hydrologist-Water Supply Specialist for NRCS Snow Survey in Idaho. “Diminished agricultural irrigation water supply is also predicted for the Snake River above Heise, Oakley, Salmon Falls, and the Owyhee basins. Dry conditions across Idaho will continue to impact ranchers who utilize non-irrigated pastures.”
Streamflow, snowpack, and precipitation data for each basin can be accessed on the NRCS Idaho Snow Survey web page.
For information on specific basins, streams, and reservoirs, please view the full report online at May Water Supply Outlook Report.