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Experimental River Operations At Little Goose, Lower Granite Go Into Effect To Aid Sockeye
Posted on Friday, July 24, 2015 (PST)

Endangered Snake River sockeye salmon passage at Lower Granite Dam on the lower Snake River has stalled, leaving 300 or more of the salmon somewhere in the downstream pools.


Fisheries managers believe the fish (listed as endangered under the federal Endangered Species Act) have stalled due to overheated water in reservoirs and at the entrance to the Lower Granite and Little Goose dams’ fish ladders.


This week water temperatures at the ladder entrances hovered around 71 degrees.


While the managers generally agree that the warm water is the cause for the dismal fish passage through the dams, they don’t agree how best to cool the river and fish ladders, enticing sockeye salmon up through the two dams, without also impacting migrating juvenile chinook salmon, listed as threatened under the ESA.


As of July 21, 919 sockeye had passed Ice Harbor Dam on the Snake River, 816 had passed Lower Monumental Dam, 495 made it past Little Goose Dam, but just 321 had made it the distance to Lower Granite Dam, the most upstream of the four lower Snake River dams, according to information released by NOAA Fisheries Thursday.


This is just a fraction of the fish that have passed Bonneville Dam.


“We’ve seen less than 10 percent of the fish (at Lower Granite Dam) that passed Bonneville Dam. Ninety percent have disappeared,” said Paul Wagner of NOAA Fisheries at Wednesday’s regional Technical Management Team meeting. “From a record run to a bust.”


Last week the Idaho Department of Fish and Game asked NOAA for an emergency action that would allow biologists to trap and transport adult sockeye from Lower Granite Dam to the Sawtooth Valley in Idaho.


This week, according to Russ Kiefer of IDFG, Idaho promoted an experimental operation that encompassed both Lower Granite and Little Goose dams. The combined operation went into effect Thursday.


It includes: Operate Lower Granite Dam’s Unit 1 as the priority turbine unit through the rest of the summer; spill the remainder of the river in a uniform pattern. Trap and haul as many adult sockeye to Sawtooth Valley and safety-net hatchery programs as is practicable.


All the fisheries managers agree with this operation, which began a couple of weeks ago. Putting most of the water through Unit 1, the closest turbine to the fish ladder, they believe, will provide flow and slightly cooler water right next to the fish ladder and attract the fish to the fishway entrance.


However, there was disagreement on the Little Goose operation proposed by Idaho, which is to operate Units 1 and 2 from 4 am to 8 pm with no spill in two-day blocks beginning July 23 at 4 am, and to operate spillways normally, which is to operate one turbine and spill the remainder, from 8 pm to 4 am.


In a letter, NOAA Fisheries staff recommended this operation at Little Goose Dam as a test “to assess whether more adult sockeye can be encouraged to concentrate near the ladder entrance and increase the proportion of these fish passing upstream over the dam over the next 1-2 weeks.”


“Given the relative importance of Endangered adult sockeye salmon, (compared to likely effects on Threatened fall Chinook smolts), NMFS believes that actions attempting to improve passage conditions – which, if successful would provide additional adults for the trap and transport efforts at Lower Granite Dam – are warranted,” the letter continued. “The operation of two powerhouse units during the time of highest adult sockeye passage would provide all the flow and the coolest water near the fishway entrances, encouraging sockeye to congregate, and find the ladder entrances. This would likely increase the probability that adults will successfully pass upstream through the fishway and migrate on to Lower Granite Dam.”


TMT will meet Monday, July 27, to assess whether this operation is working (see TMT’s agenda for July 27 at and at least weekly for as long as the operation occurs.


The Oregon Department of Fish and Wildlife opposed the Little Goose operation and Thursday issued a warning that it was elevating the issue to the Regional Implementation Oversight Group.


“Given Oregon and others earlier objection to this planned operational change at Little Goose Dam and the solidification of a similarly premised special operation that did not clearly demonstrate an association between the operational changes at Lower Granite Dam and adult sockeye passage over Lower Granite Dam, we feel it necessary to elevate this discussion to the Regional Implementation Oversight Group process,” wrote Erick Van Dyke, Oregon’s representative to TMT, in an email to TMT members. 


Fisheries managers had met Monday to consider Idaho’s proposal, but there was a lack of consensus. Oregon clearly opposed the operation at Little Goose and Steve Haesecker of the U.S. Fish and Wildlife Service worried juvenile chinook passage at Little Goose Dam would suffer.


Charles Morrill of the Washington Department of Fish and Wildlife wondered if the lost fish are really still there below Lower Granite and Little Goose dams, although he didn’t object to Idaho’s proposal.


However, Kiefer, clearly distressed by the lack of movement by whatever sockeye are still in the river, made an impassioned plea to at least try the operation and check its success after the weekend.


“Our idea is to change things up, and by changing to get the sockeye to pass,” Kiefer said. “The more we delay (changing operations at Little Goose), the more they die. There is a passage issue at Goose and time is critical.”


“Russ (Kiefer) makes a reasonable proposal. The sockeye are on life support,” said Jim Litchfield, representing Montana at TMT. “On the other hand, fall chinook are migrating. If I was to take risks, I’d side with the sockeye.”


Another tool managers have to keep the Snake River cool at Lower Granite Dam is releases of cool water from Dworshak Dam. Releases have been at full powerhouse, about 9,500 cubic feet per second, since last week. In an effort to conserve water in the Dworshak reservoir for August flows, Steve Hall of the Army Corps of Engineers in Walla Walla suggested dropping flows to 7.5 kcfs while air temperatures are lower in Idaho, which they did Thursday at midnight. Flows will be adjusted if conditions change.


If flows continue at full powerhouse through July, Hall said, then average flows from Dworshak during August would be 6.1 kcfs. If flows drop to 7.5 for just four days, August flows could be 6.4 kcfs.


To further complicate the task of keeping water cool in the lower Snake River, Idaho Power will begin releasing 71 degree water beginning the first of August from its Hells Canyon Dam. That will create a challenge to meet the 68 degree required temperature in the Lower Granite Dam tailrace, Hall said. The company is required to release a total of 243,000 acre feet of water in early August to augment flows, regardless of the water temperature.


For background, see:


-- CBB, July 17, 2015, “Snake River Sockeye Trapped, Transported At Lower Granite; ‘Fish Are Stressed And In Rough Condition,”


-- CBB, July 10, 2015, “Lower Granite Tailwater Temps Go Above 68 Degrees; Returning Snake River Sockeye Stalling Through System,”


-- CBB, June 12, 2015, “NOAA Fisheries Releases Snake River Sockeye Salmon Recovery Plan: 25 Years Of Actions At $101 Million”


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