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NW Fishletter #391, March 4, 2019

[4] NW Power And Conservation Council Gets Spill Overview From Feds, States, Tribes

The Northwest Power and Conservation Council got a first-hand explanation from the federal agencies, states and tribes involved in a new flexible spill agreement that goes into effect in April, if Washington state modifies its total dissolved gas limits.

The players who negotiated for almost a year to develop a spring spill regime to replace last year's 24-hours-a-day, spill-to-gas-cap program offered perspectives on their end of the deal in an hour-long presentation on Feb. 13.

More details about the new agreement--such as its potential impact on summer spill, and the uncertainty of the 2020 spring spill to be finalized based on what's learned this year--emerged during the presentation.

Bonneville Power Administration Administrator Elliot Mainzer introduced the presenters, commending them and others for the collaboration it took to work through the "incredibly divisive and incredibly challenging" issue of spring spill at eight federal dams on the Snake and Columbia rivers.

He said the team "built trust and tried to really understand each other's perspectives" to develop the three-year agreement that avoids continued litigation over the early April to mid-June spill. The agreement is designed to boost juvenile survival while protecting Bonneville's customers from additional rate increases from spill.

Its premise is based on three pillars--benefits to fish and to power generation, and operational feasibility.

Under the agreement, juvenile fish in 2019 will benefit at least as much as they did under the 2018 spill, and in 2020 will benefit more.

In both years, the Bonneville Power Administration's earnings from power generation at these dams will at least match its earnings under the 2018 court-ordered spring spill.

For the U.S. Army Corps of Engineers, the operational changes will be feasible, and not interfere with the Corps' Congressionally authorized purposes that--depending on the project--could include flood risk management, navigation, irrigation, water supply, fish and wildlife conservation, recreation, water quality control, and hydropower generation.

The agreement is in effect until a record of decision is issued for the Columbia River System Operations environmental impact statement. That was initially planned for release in 2021, but is now scheduled for 2020.

Mainzer said he's hoping the agreement and the trust that was developed will serve as a model as the region develops its long-term strategy for operating the hydroelectric system.

"It's kind of nice not to be the fly in the ointment on every issue," Ed Bowles, fish division administrator for the Oregon Department of Fish and Wildlife, told the Council while explaining the juvenile passage benefits his agency expects to see under the agreement.

Bowles said with a long history of tracking spill levels, the impacts to fish when TDG levels are raised to 120 percent this year and to 125 percent in 2020 are not untested. "Most of that is based on the bounty of spring runoff, and uncontrolled spill," he said.

Bowles said while the agreement focuses on spring operations, it may also reduce the summer spill, if necessary. He said the concept is to increase spill during the 16 hours of each day when hydroelectric demand is relatively lower, and then reduce spill for the eight hours when demand is higher. "This is primarily thought of on a daily basis, but it also applies spatially, among the dams," he said, noting that all eight dams are not required to operate in the same way.

According to key points listed as part of the agreement, only Little Goose Dam on the Snake River will be limited during its reduced spill periods to at least four hours--not to exceed five hours in the morning--and to no more than four hours in the evening, in order to help with adult passage issues.

All other projects can spill for either three or four hours in the morning, and then up to five hours in the evening, as long as the reduced spill time does not exceed eight hours in a day.

In addition, controlled spill will be capped at 150,000 cubic feet per second at Bonneville Dam due to erosion concerns, and will be contained between the walls (between bays 1 through 8) at The Dalles unless river flows exceed 350,000 cfs.

Bowles later noted that adaptive management is an essential piece of the agreement. He said that although the juvenile fish that benefit from the increased spill won't return before an environmental impact statement for Columbia River System Operations is issued, they will be closely monitoring and evaluating all aspects of the flexible spill.

Jay Hesse, director of research at the Nez Perce Tribe of Idaho's fisheries department, said that, in developing the benefits for fish, the team needed a quantifiable way to compare operations, and settled on decreased powerhouse encounter probability, or the likelihood that juveniles would travel either through a turbine or a juvenile bypass facility. Increasing spill decreases the likelihood of those encounters, he said, and has also been shown to increase smolt-to-adult returns, which should increase adult abundance in the river system.

Compared with the court-ordered spill in 2018, the flexible spill this year--at 120 percent TDG--is expected to reduce powerhouse encounters only slightly, he said. That will drop even further under the 2020 flexible spill allowing up to 125 percent TDG, cutting those encounters in half compared with the 2014 biological opinion levels.

Dave Johnson, fisheries department manager for the Nez Perce Tribe, explained that the tribe is involved because the legal effort to force operational changes on the dams was one of its last alternatives for improving fishing opportunities for its members.

"Where we live--where we are on the Snake River--there are all these areas we really can't do anything about," he said. "We can't put fish there, we can't fix the habitat ... the harvest we have is always curtailed."

Jason Sweet, manager of BPA's Fish Operations Policy and Planning Group, noted that as part of the agreement this year, spill can be reduced to 2014 biological opinion levels for up to eight hours a day, and summer spill levels will be based on the performance standard results through Aug. 30. In 2020, there will likely be some variation on the six projects that will spill up to 125 percent TDG levels for 16 hours, with eight hours of flexible spill reductions. The Dalles and John Day dams will likely be held to current spill levels, and summer spill will be the same as this year, but reduced to minimum levels Aug. 15-30.

He said figuring out whether this will work economically was challenging, but BPA used 80-year runoff levels and daily pricing models to show how flexible spill can improve revenues under most flow conditions, and keep them at least at 2018 levels. But whether it works will depend on the actual flows and market values, he noted.

Sweet said if the difference between average hourly prices at peak times of day and average hourly prices at non-peak times isn't great enough, the added spill for 16 hours won't be offset by reducing spill during high-value times, and they'll try to make up for it by reducing spill in the late summer. "It's not an elimination of summer spill, but it is a reduction," he said.

From an operational standpoint, Tim Dykstra, the Corps' senior fish program manager, told the Council that--just like last year's court-ordered spill--his agency will attempt to meet but not exceed the total dissolved gas levels set by the states. Washington is working to modify its limits in the Snake and Columbia rivers to meet Oregon's, at 120 percent TDG, by the end of March. Both states will then seek to raise them to 125 percent TDG before next spring's spill season.

Dykstra said these changes are expected to be slightly easier for operators compared to last year's spill, which required different TDG levels in the dams' forebays compared with their tailraces. "We don't know," he said. "We won't know until we begin implementation." But, he said, dam operators are used to making in-season adjustments, and "On paper, it looks pretty straightforward."

NOAA Fisheries expects to issue a new biological opinion that includes flexible spill this spring, and flexible spill will also be evaluated in the Columbia River Hydro System EIS.

Several Council members praised the team for its work. Council Member Ted Ferrioli, from Oregon, said that while "not everybody may share your enthusiasm for spill," the agreement is going to be a wonderful thing due to the "idea of doing something beneficial to fish with a lower threshold for pain." -K.C. Mehaffey

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NW Fishletter is produced by NewsData LLC.
Publisher/Editor-in-Chief: Mark Ohrenschall, Editor: K.C. Mehaffey
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