Originally published in Columbia Riverkeeper “Currents” Issue 1, 2026
Fighting the Underwater Power Line.
By Teryn Yazdani, Staff Attorney
When I joined Columbia Riverkeeper’s staff two years ago, one of my earliest tasks was investigating a new project. It sounded outland-ish: a proposal to lay a massive electrical transmission line under the Columbia River, from The Dalles to Portland, near the navigation channel. Using a jet of high-pressure water to break apart the riverbed, a device called a hydroplow would create an underwater trench up to 10 feet deep and 100 miles long. The power line would be dropped into the trench from a ship, and left there indefinitely. Where the river bed is too hard, the developer proposes to lay the power line directly on the river bottom, weighed down by concrete or rocks. To get around Bonneville Dam, the power line would be buried on land in Washington for approximately seven and a half miles.
From the start, this project raised serious questions. Through collaboration with the Columbia River Inter-Tribal Fish Commission and Columbia River Tribes, our understanding of Tribal and environmental concerns grew. While large underwater power lines are not entirely new, their use in freshwater environments like the Columbia River is experimental. This project’s true environmental impacts on Columbia River fish and aquatic life are untested and unknown. While other underwater power lines exist, they are often in more developed areas, like the San Francisco Bay, with different species and environmental needs, and wider areas for fish passage around the line.
The Columbia River, and its species and communities, are already significantly overburdened by energy development. Reservoir construction profoundly altered the river ecosystem and created water temperature problems that are only made worse by climate change. The river, and those who depend on it, already pay a high price to help meet the region’s energy demands. This project would continue that trend and set a precedent that our region’s waterways are fair game for similar energy infrastructure.
It sounded outland-ish: a proposal to lay a massive electrical transmission line under the Columbia River, from The Dalles to Portland, near the navigation channel.
Columbia Riverkeeper has many concerns about the short- and long-term impacts of this project. First and foremost, the power line, a high-temperature cable bundle, could add heat to 100 miles of an already overheated river. Other concerns include, but are not limited to the development’s:
- electromagnetic field impacting fish migration;
- reintroduction of contaminants into the water column by disturbing polluted river sediment;
- and impact on Tribal treaty-protected resources, Tribal fisheries, First Foods, and culturally significant riverbed areas.
Another large concern is the developer’s refusal to look at meaningful alternatives for this project. Failure to look at out-of-river alternatives paints an incomplete picture and ignores Tribal Nations’ and the public’s demand for other ways to meet energy needs without permanently degrading the river.
The developer claims this power line is for “renewable” energy, but Columbia Riverkeeper is not convinced. So far, the developer has failed to make any binding promises that this project will not transmit fossil or nuclear energy. Additionally, we have serious questions about who this power line will ultimately benefit; the developer makes no guarantees it won’t serve large tech clients like data centers.
To date, the developer has failed to answer basic questions about the environmental impacts of this monumental project and provide clarity around the power line’s true need
and end use. The implications of this one proposal could be felt for generations, transforming the Columbia River into a transmission corridor. With state and federal permitting processes now underway, Columbia Riverkeeper is working hard to ensure that decision-makers prioritize salmon protection, river health, and Tribal treaty rights.
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