With no rain in the forecast, continuing to provide flows for chum below Bonneville Dam is a tough decision, fish managers and dam operators who work together to manage Columbia River flows for fish agreed Nov. 6.
But after starting chum operations on Nov. 4, it would have been an even tougher call to stop releasing water for this threatened species, even though only a handful were there to take advantage of it. By Nov. 8, the chum were coming in strong and the issue was moot, Tony Norris, Bonneville Power Administration analyst and member of the Columbia River Technical Management Team (TMT) told NW Fishletter.
When streamflows in the Columbia Basin are low, Lake Roosevelt—the reservoir behind Grand Coulee Dam—provides the bulk of water for chum that spawn below Bonneville dam in late fall and through the winter. Those operations, which ensure at least 11.3 feet of water in Bonneville's tailwater, are causing the reservoir to drop by about six inches every day.
TMT members learned Nov. 6 that without rain, continuing to provide those flows will put the reservoir's elevation around 1,271 feet by the end of November. "The last time we were below 1,275 [feet] was 1988, so it's been quite a while since we've been that low by the end of November," Bureau of Reclamation's John Roache told TMT members. The reservoir was at 1,284.6 feet on Nov. 6, he said.
Depending on winter precipitation, the drawdown could also impact the agency's ability to hit its April 10 elevation goals at Grand Coulee Dam next year, he added.
Sheri Sears, TMT member representing the Confederated Tribes of the Colville Reservation, noted that when Lake Roosevelt drops, it impacts her whole tribe. "If we have no access to even get on the river to do work or transport back and forth, it can be very impactful up here," she said.
But stopping and restarting the flows from Grand Coulee proved too complicated, as it takes time for the water from the upper Columbia to reach Bonneville Dam, and the flows also benefit nonlisted Chinook in the area.
Charles Morrill, who represents Washington state on the team, said despite the potential impacts, he favors keeping the flows coming. "If we didn't, we would eliminate the opportunity for chum to spawn in the preferred areas, and that's not something we would like to see nor is it supported in the [biological opinion]," he said.
As for the potential for a solution from Mother Nature, he added, "It's not a very optimistic outlook, but let's keep our fingers crossed."