More Spill, Fewer Answers

For years, increasing the amount of water spilled over federal dams on the Columbia and Snake rivers has been promoted as a way to help young salmon migrate safely to the ocean. This year, a federal court ordered even more water to be spilled, and for longer periods of time.

The goal is to protect salmon. But the data is raising an important question: Is more spill actually helping the fish?

It's a question worth asking because increased spill affects salmon as well as the supply and cost of electricity throughout the Pacific Northwest.

What changed?

Juvenile salmon migrating toward the ocean must pass a series of dams along the Columbia and Snake rivers. Over decades, dam operators have developed several ways to help them make that journey safely, including fish bypass systems and surface passage structures.

Some spill can be beneficial. By sending water through spillways rather than turbines, juvenile fish can avoid passage through the powerhouse. But the effects of the significantly higher spill levels recently ordered by a federal judge are not fully understood.

Beginning in the late 1990s, spill requirements increased through a series of operational changes and court decisions. Most recently, litigation brought by the states of Oregon and Washington and other parties resulted in a federal court order requiring significantly increased spill at Columbia and Snake River dams for an extended period.

The new operations are intended to improve fish survival. However, fisheries experts interviewed by Adam Ratliff for his Armchair Engineer video, The Dams Are Killing the Fish, say the data does not show improved juvenile survival or adult returns as spill levels have increased.

The question isn't whether spill can benefit fish. It can. The question is whether more spill provides more benefit.

When more spill creates another problem

This summer provided a striking example.

Adult Chinook salmon returning from the ocean normally pass Bonneville Dam, The Dalles, John Day, and McNary dams as they migrate upstream. Fish ladders provide a current that returning salmon can detect and follow around the dams.

In June, that familiar migration pattern changed.

Large numbers of Chinook successfully passed Bonneville and The Dalles but accumulated below John Day Dam. Ratliff's video documents reports that the high volume of spilled water made it difficult for returning fish to locate the fish ladder. At one point, approximately 75% of the fish were reportedly failing to continue upstream. Dam operators sounded the alarm, and spill was temporarily reduced under emergency operations.

The irony is difficult to ignore: Operations intended to improve conditions for juvenile salmon migrating downstream appear to have created problems for adult salmon trying to migrate upstream.

There are also important differences in how young fish pass a dam on their journey downstream. Surface passage structures allow fish near the top of the reservoir to move over a dam with relatively little pressure change. Deep spill, such as that recently ordered by the federal court, requires fish to descend farther into the water column before passing beneath spillway gates, exposing them to much harsher conditions.

Ratliff's video examines research comparing survival through turbines, bypass systems, deep spill, and surface passage, illustrating why treating all spill as equally beneficial can be misleading.

There is an energy and environmental cost, too

Water spilled over a dam cannot be used to generate electricity at the same time.

Central Lincoln purchases all of its power from the Bonneville Power Administration (BPA), which markets electricity generated by the federal Columbia River power system. When spill reduces generation and BPA does not have enough power to meet customer demand, it must purchase replacement electricity from the wholesale market, which can include power generated from fossil fuels.

Those purchases can be expensive and carbon-intensive.

Central Lincoln implemented its planned 3% rate increase in July. We had also been preparing for the possibility of an additional rate increase due to BPA's costs from the court-ordered spill. BPA has delayed that rate action, and while the timing remains uncertain, early 2027 is currently looking more likely.

The delay, however, does not mean the underlying costs have disappeared.

Wholesale market power has recently reached around $100 per megawatt-hour, roughly twice what Central Lincoln has historically paid BPA. Meanwhile, BPA is spilling water that could be used to generate electricity and purchasing higher-priced replacement power from that same market to meet customer needs.

And BPA's customers - including Central Lincoln - bear those costs.

Increased spill also raises another question: What is the carbon impact of replacing lost carbon-free hydropower generation with electricity purchased from the market? While the full impact of this summer's operations is not yet known, it's another consequence that deserves examination as Oregon continues to pursue litigation seeking increased spill.

Are we getting the intended result?

Central Lincoln supports efforts to protect salmon. Fish recovery and a reliable, affordable, low-carbon electric system do not have to be opposing goals.

But our customers are being asked to pay the costs associated with significant changes in river operations. Those operations reduce the amount of carbon-free electricity available to the region and, based on the information currently available, have not demonstrated that recent increases in spill have resulted in a measurable improvement in salmon survival.

We believe that deserves scrutiny.

The issue is bigger than whether someone is "for" or "against" dams. It's whether decisions affecting fish, electricity reliability, carbon emissions, and millions of Northwest ratepayers are producing the results they were intended to achieve.

Adam Ratliff's Armchair Engineer video provides an accessible, detailed look at the issue, including fish-count data, dam-passage survival information, river-flow and generation data, court documents, and perspectives from fisheries and power-system experts.

We encourage customers who want to learn more to watch the full video and review the underlying information for themselves.

Watch "The Dams Are Killing the Fish" from the Armchair Engineer.

Central Lincoln will continue to advocate for affordable, reliable, and safe electricity for our customers and to ask whether policies that carry significant costs are delivering measurable benefits.