the film forum library tutorial contact

Fish Managers Want McNary Fish Passage Tests Halted by Mike O'Bryant Columbia Basin Bulletin - May 21, 2004

Research at McNary Dam is endangering juveniles migrating through the dam, say regional salmon managers, prompting them to ask the Army Corps of Engineers this week to operate all turbines at the dam within the 1 percent peak efficiency range, which is required by the NOAA Fisheries 2000 Biological Opinion, and to cease the Vertical Barrier Screen (VBS) tests, which require operation of turbine units at the dam outside that range.

The salmon managers at this week's Technical Management Team (TMT) meeting said that operating the turbines outside the 1 percent efficiency range is increasing the immediate and delayed mortality of juveniles migrating downriver. They made a similar request at the March 16 TMT meeting.

"We're concerned that the increased rates of mortality and descaling we're seeing at the dam don't justify continuing this," Dave Wills, U.S. Fish and Wildlife Service, told operating agencies at this week's Technical Management Team meeting as he described the systems operational request (SOR) asking for tests at the dam to stop. "We're very concerned about the mortality rates and its detrimental affect on fish passage."

At another meeting this week in Walla Walla, after considering the evidence, dam operators and biologists decided to delay the tests scheduled this weekend at McNary Dam. The Fish Facilities Design Review Work Group (FFDRWG - pronounced "fidderwig") also met this week to discuss the higher scaling and mortality that seems to be resulting from the test. FFDRWG is made up of engineering and biological staff from the Corps and other state, tribal, and federal agencies.

The SOR said that mortality rates this year are almost five times greater than the 1999 to 2003 average for yearling chinook and over seven times greater for steelhead. Further, descaling rates this year are 1.7 percent higher than the 2000 to 2003 average for yearling chinook and 1.5 percent higher for steelhead. Finally, increases in mortality are observed when more turbines operate outside the 1 percent efficiency range, the SOR said. "For these reasons, we recommend that operations outside of 1% for the purpose of testing the extended VBS cease," the SOR concluded.

"There seems to be a correlation between when the units run outside the 1 percent and descaling and mortality at the McNary facility," said Paul Wagner of NOAA Fisheries, which didn't sign the SOR. He said that NOAA would prefer to continue the tests to make sure the cause of the descaling and mortality is the operation outside 1% turbine efficiency. However, he did say that appeared to be the cause.

"Like any research project, you need to do the test wisely and keep in mind impacts on the current migration," said Ron Boyce of the Oregon Department of Fish and Wildlife. "There has to be a balance between getting the information and taking care of the migration. Research is secondary to the primary goal of taking care of the fish."

Descaling and mortality have skyrocketed, he added, and the salmon managers have reached a point at which it's not acceptable to continue the research.

The NOAA Fisheries 2000 biological opinion of the Federal Columbia River Power System's reasonable and prudent alternative (RPA) number 58 calls for turbines to be operated within the 1 percent peak efficiency range during spring and summer while juvenile salmon migrants are in the river. The operating limits were set as a result of studies in the 1980s that determined turbine efficiency and fish survival are directly related.

After re-evaluating those studies, BPA concluded that operating outside the 1 percent efficiency limit at McNary may not result in survival different than operating within the 1 percent limit. If the dam can operate outside the 1 percent limit, it could spill less water and put more water through turbines to generate as much as $5 million more electricity each year in an average water year, BPA has said.

Related Sites:
Technical Management Team: www.nwd-wc.usace.army.mil/TMT/index.html

Related Pages:
Fish Managers Still Push for End to McNary 1 Percent Tests Columbia Basin Bulletin, 5/28/4
River Managers Spill to Deal with Brief Rise in Fish Mortality Columbia Basin Bulletin, 5/7/4