On a chilly, wet November morning, Leaburg Lake felt uncharacteristically quiet, with only a couple of ducks stirring, slowly drifting along the still banks. Even the neighboring hatchery looked deserted at first glance, the once-brimming pools drained of their water. The area, advertised for life and recreation, seemed like a ghost of itself. And in a way, it was.
In January 2023, the Eugene Water and Electric Board (EWEB) announced that the Leaburg dam will be decommissioned and the removal of all its structures from the McKenzie River will begin by 2032. But nothing about how that decision came to be made, or the impacts it will have on the environment around the river, are so simple.
Originally built in 1929, the Leaburg dam was a small hydroelectric project on the McKenzie River outside of Eugene, Oregon. Its construction created the Leaburg Lake upriver, providing the water for the Leaburg Hatchery just downriver. The top of the dam itself serves as the only river crossing in the immediate area. The lake and hatchery created commercial and recreational economic growth for the community, and along with the modest amounts of electricity from the dam, the project was considered by many to be a relative success.
Before 2018, no one would have assumed the dam would be where it is now: shut down, waiting for final decommissioning and deconstruction to begin. The dam was licensed to produce electricity until 2040. But EWEB began receiving reports from locals around the dam, pointing to a grim new reality that their own monitoring devices confirmed: the dam is eroding, and now it’s reaching a tipping point.
Locals living alongside the canal began reporting “puddles” and “little creeks” forming outside the dam, says Adam Spencer, a communications specialist at EWEB. This led to what Spencer describes as a “triple-bottom-line assessment” of the economic, environmental, and social impacts of either repairing or decommissioning the dam. Ultimately, he explains, the costs of repairing the dam and building it to a modern construction code were far greater than the cost of decommissioning the dam early. So, in January 2023, a “decision was made to develop the official Leaburg Decommissioning Action Plan.
Decommissioning is just the first step in removing the dam. Turns out, you can’t just pluck an entire dam out of a river and move on. Questions about the sediment behind the dam, water levels once the dam no longer regulates the reservoir, and changes to people’s property lines will have to be addressed and approved by stakeholders. There’s also the big question: What environmental impacts will a seismic change bring to the river system after 100 years?
Removing the dam will be a boon to struggling fish populations, Spencer says. He also highlights that by removing the dam, the lake will disappear and the river will return to a free-flowing state.
“A flowing river won’t heat up as much, and water temperatures are one of our greatest threats due to climate change,” Spencer says. Higher water temperatures allow for more disease and algae to build up in waterways, and by allowing the river to flow free, decommissioning the dam helps mitigate that impact and reduce stress on the fish population. But the lake is also a habitat.
Spencer admits that the environmental impacts on the local waterfowl that use the habitat are somewhat unknown. Beyond the end results, though, the deconstruction itself could bring short-term risks of material spills into the water that would further negatively impact the environment. The decision for decommissioning, he says, is ultimately “really, really good for economics,” but only “pretty good” for environmental impacts.
Leaburg is one of several dams on the McKenzie River, owned by myriad utility and government bodies, all with varying levels of impact. The Army Corps of Engineers is actively reviewing its management of Willamette Basin dams, as is the Bonneville Power Administration. Hydropower is a major source of energy in the Willamette Valley, with the dams accounting for 184.4 MW of electricity for more than 130,000 homes, but the dams cause a range of negative environmental impacts. Additionally, Spencer warns that as the population of the valley continues to grow, the current energy output will not be able to match it. He warns of rolling blackouts by 2027 and increasing threats from global warming to both our environment and power grid. There is more to be done and more to be studied, and the Leaburg Dam decommissioning is only the beginning.
Despite this beginning, it is an ending for this historic location. Spencer mentions he’s from the area, so he “really resonated with the folks who are sad to lose it.” But he still keeps a hopeful vision for what’s to come: “In 15 years, the McKenzie will be back in its traditional place, with reappearing forest and vegetation, and really clean water.
