Water volumes in southwest Idaho reservoirs are about average, according to the U.S. Bureau of Reclamation.

“There is still reasonable carryover” from the 2024 irrigation season, said Ryan Hedrick, hydrologist with Reclamation’s Middle Snake region in Boise.

Lower recent totals in part reflect a stretch of dry weather this fall, he said.

Whether reservoir systems will contain a plentiful supply of water for irrigation and other uses will depend on the 2024-2025 snowpack, Hedrick said.

The Boise River reservoir system volume was around 368,000 acre-feet Nov. 1, down 24% from 485,000 a year ago but 3% above the long-term average of about 357,000, he said.

Kuna-area farmer Dave Reynolds expects a wetter winter than last year’s but plans to operate mostly as normal in the 2025 crop season.

“I’m always worried about it and cognizant of it, but a lot of my farm is clay dirt,” Reynolds said of Boise River reservoir volumes. “I’ve got to farm it as normal and adjust as I have to. … That is kind of always how it plays out because you just don’t know.”

Heavy tillage and bedding work are underway on the gravity-irrigated farm “so when we go into spring, we’re doing very little tillage,” he said.

Winter moisture goes into the seed beds, which settle over the winter — a process that removes air pockets, reduces clotting and helps with seeding, Reynolds said.

“We try to play the stats and stack the odds knowing a lot of unknowns are coming down the pike,” he said.

As for Boise River reservoir volumes, “it was a long, dry summer this year,” Reynolds said. “We used a lot of water.”

Since irrigation supply is about equally divided between reservoir-stored water and streamflows, low snowpack can cause problems even when reservoirs are full, he said.

In the Payette River system, Nov. 1 volume was about 434,000 acre-feet, down 9% from 477,000 a year ago and 8.4% below the average of about 474,000, Hedrick said.