Northwest water year starts with record rainfall
BOISE — The 2017 water season was kick-started with abundant rain in many parts of the Northwest during September and October.
Many areas received record amounts of precipitation, Natural Resources Conservation Service water supply specialist Ron Abramovich said Nov. 10 during a water supply outlook conference in Boise.
“This is exciting,” he said.
Abramovich also said soil moisture levels are better than last year heading into winter. “This is more good news. We will feel the impacts of that next spring when the snow starts melting.”
A persistent series of storms made October the wettest on record in Idaho and the second wettest in Oregon, said Kathie Dello of the Pacific Northwest Climate Impacts Research Consortium.
Other parts of the Pacific Northwest also received lots of rain in October. Much of the Columbia River Basin received 200 percent of normal or more, said Troy Lindquist, senior hydrologist at the National Weather Service’s Boise office.
“A lot of records were set,” he said. “It was a really good start to the water year.”
Although November has gotten off to a dry start that could change starting the middle of next week, as a new weather pattern is expected to bring more precipitation to the Northwest.
Lindquist said there is a 70 percent chance of La Nina conditions developing during the fall and continuing through the winter.
La Nina conditions typically mean cooler and wetter conditions than normal in the Northwest, he said. Stream runoff is also typically above normal during a La Nina, he added.
The not-so-great news for irrigators who depend on a good water supply is there “wasn’t a lot of carryover in some of the major reservoirs, so we need to wait for winter to play out,” Dello said.
“I hope La Nina comes through for us,” said Brian Sauer, a water operations manager for the U.S. Bureau of Reclamation.
There is some uncertainty among various forecasts over what a La Nina pattern will mean to the region and that is a little concerning, said Jay Chamberlin, manager of the Owyhee Irrigation District, which provides water for 1,800 farms and 118,000 acres in Eastern Oregon and part of Southwestern Idaho.
But the general forecast for cooler weather and above-normal precipitation is encouraging, he added.
The Owyhee reservoir hasn’t filled since 2011. This year was the first time since then that OID patrons have received their full allotment of 4 acre-feet of water.
The reservoir ended this water year with 166,000 acre-feet of carryover water, much less than normal but much more than the previous three years.
“The cards are still out there but the potential for the 2017 water season I think is better for us,” Chamberlin said. “We’re carrying some extra water over and the (forecast for) cooler, wetter weather certainly feels a lot better.”