BOISE – The Natural Resources Conservation Service has released the third water supply outlook report for the 2018 water year.
Precipitation since the water year started on October 1, 2017, varies across the state with watersheds ranging from 70 to 130% of normal.
“Streamflow forecasts mirror the current snowpacks,” said Ron Abramovich, Water Supply Specialist with the Idaho Natural Resources Conservation Service. “The early March storm added much-needed water to the snowpack. Another March storm or two, or a wet spring will help ensure supplies are adequate in all the basins.”
The highest snowpacks continue to be found in the Clearwater basin where collectively they are 123% of normal thanks to the La Nina storm track. Conversely, the Owyhee snowpack is the lowest at 35% of normal. “More snow is needed across central and southern Idaho, and colder temperatures would help keep the snow in place until spring,” Abramovich noted.
Based on the current snowpack and reservoir storage, water supplies may be marginal in the Big Wood, Big Lost, and Little Lost basins. Idaho’s southern reservoirs, Owyhee, Salmon Falls, Oakley and Bear Lake, are not expected to fill this year, unless conditions become much wetter, but are in good shape to provide adequate irrigation supplies this summer. With the Upper Snake reservoir system at 87% full, 130% of average, there will be plenty of snowmelt water to fill the reservoirs and to meet Idaho’s water users needs and put excess water into the aquifer.
For information on specific basins, streams, and reservoirs, please view the full report online at March Water Supply Outlook Report.