Lewis River model links juvenile salmon production to improved collection at hydropower dams

Washington is protecting its hydropower sector and the vital Coho salmon using specialized interventions.

Across the United States, developers are struggling to balance clean power generation with wildlife preservation.

The nation’s giant dams have historically fragmented vital aquatic ecosystems, blocking native fish migration routes.

However, maintaining this vital energy source while protecting native aquatic wildlife is becoming more challenging, especially as climate change accelerates.

As accelerated climate change intensifies ecological impacts, innovative mitigation efforts are essential to ensure conservation.

What engineering solutions can help local wildlife coexist with renewable power infrastructure?

How hydropower’s role has become fundamental in Washington

Washington state is the leading producer of hydroelectric power in the United States.

Hydropower supplies almost 63 percent of the state’s total electricity.

It serves as a reliable baseload clean power asset, helping to meet strict climate regulations.

State mandates include achieving greenhouse gas-neutral electricity by 2030.

Furthermore, 100 percent of electricity supplies must come from renewable sources by 2045.

However, this source’s role has significantly evolved beyond green ambitions.

Regional electrification and rapid digitization have surged power demand.

Electricity demand is predicted to increase by 50 to 100 percent by 2046.

This means hydropower generation has become even more crucial in keeping the local grid stable and preventing regional blackouts.

It therefore offers a dual solution, as it replaces fossil fuels without causing intermittent gaps in power production.

However, maintaining this vital energy source while protecting native aquatic wildlife is becoming more challenging, especially as climate change accelerates.

The ecological pressure on vital native fish species

Across Washington state, native fish species hold immense cultural, ecological, and economic importance.

This is especially true of the coho salmon.

They are a vital species that sustains regional fisheries and supports whole forest food chains.

Unfortunately, massive hydroelectric dam projects have historically placed immense ecological pressures on these migratory fish.

The large concrete infrastructure has become a barrier that fragments aquatic corridors.

This blocks coho salmon from migrating to their native spawning grounds.

However, these ecological impacts are now exacerbated by accelerated climate change.

Decades of drought, warmer water temperatures, and altered river flows are pushing major river systems toward a breaking point.

This adds even more immense physiological stress on migrating fish.

The U.S. Geological Survey (USGS) plays a critical role in addressing this crisis.

Together with utility operators, advanced lifecycle models and tracking tools have been developed.

They are key to Washington State’s conservation strategies for the Lewis River coho salmon.

Saving the native coho salmon

PacifiCorp is central to this environmental recovery initiative.

The utility operates the Lewis River Hydropower Project, which has blocked fish migration.

Without intervention, the coho salmon drifted near local functional extinction upstream.

Standard fish ladders at the hydropower station were not ideally suited to reverse this decline.

Instead, comprehensive conservation strategies were implemented.

The Lewis River Fish Passage Program

At the Merwin Dam, upstream collection facilities were added to trap returning adult salmon.

They were then transported past the barriers using “shuttles.”

At the Swift Dam, a floating surface collector was added. The collector safely gathered and moved downstream-migrating juvenile salmon past the dam.

By using rigorous monitoring and adaptive management, population numbers increased significantly.

This program has successfully restored access to more than 100 miles of upstream habitat.

As a result, the fragmented Lewis River has become a thriving fish habitat once again.

The trap-and-haul program of the Lewis River proves that renewable energy infrastructure and wildlife conservation can successfully coexist.

This model serves as an essential guide for other hydropower facilities facing similar ecological challenges.

Adaptive management, advanced floating collectors, and the USGS lifecycle models are key to saving native aquatic wildlife.

Ultimately, scaling these mitigation strategies worldwide will secure the future of major hydroelectric networks while protecting migratory fish populations.