Low flows in Walla Walla River generate concerns for salmon

However, state officials are not yet calling for a drought declaration.



The Walla Walla River near Beet Road near the diversion point for the Gardena Farms Irrigation District ditch. The river is running very low recently due to poor snowpack conditions, causing concern for spring fish migrations.

WALLA WALLA - A lot of eyes are watching the Walla Walla River these days.

What they are seeing is a low-flowing stream, which is not a good thing for seasonal fish migrations or irrigators.

Despite recent late-season storms, water levels in the river remain well below normal. However, state officials are not yet calling for a drought declaration.

A declaration specific to the Walla Walla River basin was discussed at the state Water Supply Availability Committee on Wednesday, but the consensus was to wait and see, said Robert Nelson, spokesman for the Washington Department of Fish and Wildlife.

"Everybody is encouraged by what has happened statewide in the last couple of weeks," Nelson said about the late-arriving rain and snow.

The committee will meet on Thursday to specifically discuss the situation in the Walla Walla Basin, said Dan Partridge, communications manager for Ecology's Water Resources Program.

During March, flows in the Walla Walla River were about 65 percent below average for the month, according to stream gauge measurements. The flows were far below the averages recorded in March 2009 and not far above the low flows recorded during the drought year of 2005.

For fish, the poor flows are a major concern because mid-April is when juvenile steelhead and spring chinook migrate downstream while at the same time adult spring chinook are trying to move upstream, said Paul LaRiviere, WDFW instream flow biologist.

The high volume of water in a normal spring runoff "helps move the smolts downstream and move them downstream quicker," LaRiviere said.

Low flows leave the juveniles vulnerable to predators and disease and can interfere with imprinting, which means the fish won't find their way back upstream when they return to spawn. The situation is similar for the adult chinook. Low water leaves them exposed to predators and impedes movement.

The low-flow situation has sparked discussions and conference calls at the William A. Grant Water and Environment Center, said Mike Bireley, center director.

At a meeting in late March, discussion centered on how to create "pulsed flows" in the river if necessary by enlisting the cooperation of major water-right holders. The aim would be to create a peak flow of 100 cubic feet per second in the river for a period of five days starting in mid-April to coincide with hatchery releases upstream and installation of fish screens downstream at McNary Dam by the U.S. Army Corps of Engineers.

The meeting and conference call involved the WDFW, Ecology, Washington Water Trust, the newly formed Walla Walla County Watershed Management Partnership, the Walla Walla County Conservation District, the Confederated Tribes of the Umatilla Indian Reservation and the Freshwater Trust, Bireley said.

The spring chinook migration in the Walla Walla River is a special concern for the tribes. The CTUIR and Oregon Department of Fish and Wildlife in 2000 released surplus adult spring chinook into the river to reintroduce the fish, which had been extinct in the basin for 80 years.

According to the tribe, in 2004, the Walla Walla Basin had almost 300 spring chinook returns from the efforts. Another 250,000 chinook smolts were released into the river in 2004 to continue the reintroduction effort.

Stream flows

Water flows in the Walla Walla River, past and present:

At Beet Road (36.5 miles from confluence with Columbia River) - March 2010 average, 123 cubic feet per second; March 2009, 440 cfs; normal average, 349 cfs; March 2005 average (drought year), 108 cfs.

Main stem near Touchet (18.2 miles from confluence with Columbia River) - March average, 407 cubic feet per second; March 2009, 2,062 cfs; normal average, 1,210 cfs; March 2005 (drought year), 361 cfs.

On the net

Information on the current drought situation is available at www.ecy.wa.gov/drought/index.html


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