Posted on October 5, 2026
By Josephine Woolington/High Country News
Dredge Oregon operates 24 hours a day, six days a week, with a crew of around 45. The barge, owned by the Port of Portland, is among a small dredging fleet that slurps sand in the shipping channel primarily from June until December. Its 11,000-pound steel sphere penetrates the riverbottom, churning sediment like an industrial eggbeater. As sand loosens, particles plume in an aquatic dust storm. Vibrations rattle the riverbed. Sand is vacuumed into a pipe, at about 15 feet per second, and spewed as far as two miles away. Few nearby residents notice.
“If dredging is working well, you won’t know about it,” Dredge Oregon’s navigation director, Don Tjostolvson, told a local news reporter in 2024. Ships travel in and out, he said. The economy flows.
As a riverbed is hollowed out, though, complex relationships break down. With a deeper channel and less friction from fewer sandy bumps, mounds and bars, salt water can reach farther up the estuary, and water levels around Portland are lower, according to a 2019 study by Portland State University researchers.
Creatures living in or close to the riverbed — young lamprey, sturgeon, crustaceans, crabs and clams — can get sucked into dredge pipes and killed, according to the U.S. Fish and Wildlife Service. When sand is dumped on land or in the river outside the channel, piles can bury and suffocate critters. “We are completely displacing that benthic component of the river system,” Kathleen George of the Grand Ronde said, meaning the river-bottom species that form the basis of the food chain. “The Corps has very little understanding of those impacts.” Fish and Wildlife officials also acknowledged that the Corps has not studied dredging’s effect on aquatic species in the Columbia. The Corps declined to comment.
Lamprey, a traditional food for Columbia River tribes, are of particular concern. These ancient eel-like fish migrate to and from the ocean, like salmon. For five to seven years, juveniles bury themselves in river sediment, feeding on microorganisms. But now, George said, “we see lamprey numbers year after year declining.” There were once several million, but today fewer than 20,000 return to Bonneville Dam, according to the Columbia River Inter-Tribal Fish Commission. Less than 15% can navigate past the dams.
Research in other rivers may provide some insight. A 2018 study conducted for the Corps in California’s Sacramento-San Joaquin River Delta, for example, found that dredge pipes suctioned a significant number of lamprey, invertebrates and other fish species. In the early 1970s, as some of the first dredging studies were performed, Fisheries and Oceans Canada estimated that in spring 1974, about 26,000 juvenile salmon were killed on a single day during dredging in the lower Fraser River in British Columbia. In several cases, researchers halted operations when they found the pipes inhaled substantial numbers of salmon and ooligan, or smelt, though some dredge companies didn’t comply.
In its review of the Corps’ plan for dumping dredged sand in the lower Columbia, Fish and Wildlife determined that it would harm some aquatic species, including lamprey. “These activities can have substantial and lasting effects on both fish and benthic communities, particularly in light of climate change,” officials wrote, recommending further Corps studies. The National Marine Fisheries Service concluded that while the Corps’ dredging and sand disposal is expected to “adversely affect” the region’s federally threatened and endangered salmon, it’s unlikely to jeopardize their long-term survival. That assessment, George said, allows ongoing damage to salmon and cultural sites along the river. “We need to do more to help salmon recovery by working to rebuild numbers,” she said, “not create more injury or further delay long-needed improvements in an already broken system.”
Tribal leaders and federal officials are also concerned about contaminants. Dredging may expose fish to banned toxins still present in the sediment, including PCBs, chemicals used in products ranging from plastics to motor oils. These substances have been found in the river’s clams, fish, otters and fish-eating birds, federal officials noted. As sediments suspend in the water, toxins may be released and consumed by bacteria, insects and small organisms that fish eat, cycling through the food chain. In a 2007 study led by the National Marine Fisheries Service, juvenile chinook salmon from the Columbia’s mouth contained the highest concentrations of PCBs found in any Oregon and Washington estuaries. Lamprey and sturgeon also have elevated levels of PCBs and mercury, prompting advisories from the Oregon and Washington health departments against eating either species.
Currently, the Corps tests sediment every five years. Officials assert that the sand is clean, but tribal leaders urge more testing, given the sheer amount of sediment moved — several million cubic yards annually. Tribal opinions differ concerning what contaminant levels are safe, said Cushman, of the Chinook Nation. For the Corps, “The standards are in favor of capitalist endeavors,” she said.
Upriver, a different sediment story has unfolded.
Behind Bonneville Dam, the river has become “a sandbox,” as Yakama Nation research scientist Bill Sharp, who is non-Native, described it. Cold water from tributaries like the Klickitat, Hood and White Salmon flows into the mid-Columbia, bringing with it glacial sand and silt. But instead of meeting a fast-flowing river that delivers sediments to the estuary, the particles hit a series of warm lakes created by the Corps’ hydropower dams.
In this stretch, the Columbia runs through a rocky gorge. For millennia, the rugged basalt outcroppings allowed Native fishers to net 100-pound chinook salmon at places like Celilo Falls, near the present-day town of The Dalles. To improve power generation and barge navigation, the Corps in 1957 constructed The Dalles Dam eight miles downstream from Celilo. As the dam’s steel and concrete gates closed the morning of March 10, one of the oldest continuously inhabited places in North America was drowned by the afternoon. The dam is among 18 federally owned hydropower facilities on the Columbia and Snake rivers mainstem that desecrated cultural sites and villages, displacing tribal communities.
When the dam was first constructed, its pool reached 60 feet deep, a tribal fisherman told Sharp. Now, it’s 15 feet. As wildfires rip through eastern Washington, Oregon and Idaho, more sediment spills into the Columbia. About 70% of the sand carried by the Columbia can’t pass through, Portland State University professor David Jay told The Columbian in 2018. The river is clogged, hot and shallow, Sharp said, and “bad things happen.”
The dangers once posed to cargo ships by sandbars on the lower river have now been passed upstream — and onto tribal fishers. Boats run aground on sandy shoals, damaging engine equipment. Over the years, Sharp said, several fisherman friends have died.
With so much sediment piled behind the dams, dredging this stretch of the river is one of few ways the Corps could cool the water and improve habitat.
Sandy deltas create hazards for fish, too. Young salmon travelling downstream from tributaries meet the Columbia in a sand-choked confluence where shallow pools
heat well above a lethal 68 degrees. Eleven years ago, hot water killed about 250,000 endangered adult sockeye — nearly all of the run — as they tried to return to their Idaho spawning grounds.
With so much sediment piled behind the dams, dredging this stretch of the river is one of few ways the Corps could cool the water and improve habitat. For years, tribal leaders have asked the agency to dig the mouths of several tributaries, but the Corps has yet to do so. The agency conducts some maintenance dredging to keep the mid-Columbia shipping channel 14- to 27-feet deep, extending to Lewiston, Idaho, on the Snake River. Only barges with shallower drafts can travel on locks past the dams.
In October, leaders from the Columbia River Inter-Tribal Fish Commission (CRITFC) met in Astoria in a room overlooking the 4-mile mint-green bridge across the river’s mouth. Ships passed by, but one stood out. “That boat out there,” a member noted, “that’s a dredging vessel.”
Bronsco Jim Jr., a CRITFC commissioner and chief of the Kamíłpa Band of the Yakama Nation, watched the dredge. Cargo ships the size of a city block anchored nearby. “That’s big money there, that’s priority,” he said. “But when it comes to native species and what we’re talking about in our concerns, there’s no priority.”
A Yakama Nation councilman once joked to Jim, “Tell them there’s gold in there, and maybe they’ll dredge it.”
Few rivers and harbors across the country are naturally deep enough for cargo ships. Nationwide, the Corps digs 210 million cubic yards of sediment from waterways every year to clear pathways for the massive vessels. The agency holds the most power over earth-moving in the country, fundamentally altering slow geologic processes and turning them into political acts. The consequences of moving so much sediment are unknown and understudied, as noted in Silt Sand Slurry, a 2024 book that examines dredging practices. Congress authorizes the Corps’ work and mission, but the federal government lacks a long-term nationwide dredging plan. There is no established maximum depth that the Corps could dig the Columbia. With salmon near extinction and climate change expected to diminish the river’s already weakened flows, some federal scientists and tribal leaders have urged the agency to consider alternatives.
A “paradigm shift” is needed, Cowlitz Indian Tribe Chairman William B. Iyall wrote in a 2024 public letter in response to the Corps’ proposed plan, urging officials to take a hard look at whether the river’s current 43-foot depth is ecologically and culturally viable. The Corps could opt to dredge less, he wrote. More goods could be delivered via rail or air. Ships could decrease their drafts.
But any broad change would have to come from Congress, Portland district officials said in an emailed statement. And from the agency’s standpoint, its work is not necessarily at odds with a natural river. When the agency digs sand from the shipping channel and spews it elsewhere, the sand is still in the system, Hans Moritz, a hydraulic engineer for the agency, said, though its placement is controlled. “We try to keep the river fed with sediment in a judicious way,” he said.
“If I have to explain to someone what I do for the Columbia River, I help manage sediment for the river, by the river, of the river.
“It’s a symbiotic thing.”
In the 1990s, ecosystem restoration was formally adopted as part of the Corps’ civil works mission. Lt. Gen. Henry Hatch said at the time that engineers held “most of the keys to the solutions of the world’s environmental problems.” Much of the restoration challenge, though, lies in undoing the agency’s own extensive river reshaping that began long before federal officials understood the concept of ecology.
When Congress authorized deepening the Columbia to 43 feet in the early 2000s, the Corps pledged to restore wetland habitat. But many projects never panned out, a 2010 investigation by The Oregonian found. The Corps declined to say whether any wetlands have since been restored. A 2024 report by the U.S. Government Accountability Office found that over the years, the agency has failed to inform Congress about the status of mitigation projects for fish and wildlife.
Under its new plan, the Corps has proposed rebuilding marshes by spraying sand across several thousand acres of shallow water and shoreline habitat in the lower Columbia. Few, if any, studies on the river have found that the Corps’ dredged material has improved wetland habitat, especially for salmon, though a Corps official cited a 2025 study showing that sand placed on river islands has provided nesting habitat for the streaked horned lark, a federally threatened songbird. Dredged sand is coarse and doesn’t hold the nutrients that facilitate plant growth. And immense changes to the river’s flow — through dredging, wing dams, levees and dams — have caused invasive plants to thrive. Much of the estuary’s greenery is non-native reed canarygrass and purple loosestrife, plants that threaten to colonize any open space, including newly dredged sand piles, tribal leaders and Oregon and Washington fish and wildlife officials warn.
“That’s big money there, that’s priority. But when it comes to native species and what we’re talking about in our concerns, there’s no priority.”
Scotch broom, gorse and European beach grass have taken over Sand Island at the river’s mouth, a traditional Chinookan fishing site in what’s now called Baker Bay, near Ilwaco, Washington. “There’s really beautiful historic photos of people seine netting over there,” said Cushman, describing nets that extended horizontally across the water, with floats on top and weights on the bottom, catching salmon fresh and fat from the ocean. Chinookan peoples had numerous trading posts and villages where fishers seine-netted along the lower river. It made up the river economy, she said.
In the 1930s, the U.S. military removed Chinookan people from Sand Island to make way for the shipping channel. The Corps stabilized the sand, installing wing dams and pilings to help ships navigate the mouth. Invasive plants took hold. While the Corps controls the sand, Cushman said, “they’re not caring for the actual place.”
According to Cushman, Chinookan tribal members have no say in federal river management as they’ve been fighting for sovereignty and federal recognition since first signing treaties with the U.S. government in 1851 that were never ratified. The tribe briefly regained recognition in 2001, only to have the federal government strip it away 18 months later. The Corps does not consult with Chinook leaders, Cushman said, though other federal agencies, like the Fish and Wildlife Service, have agreements with the tribe.
Grand Ronde’s elected officials said they were not consulted during planning for the proposed dredge project, George said. In a written statement, the Corps did not acknowledge this but said that it is committed to “conducting robust, meaningful government-to-government consultation with all federally recognized tribes.”
The lack of consultation leaves cultural sites and resources at risk. Of the Corps’ 106 sites where it plans to spray dredged sand along the lower river, about half have not been surveyed for cultural resources, the Corps’ report showed. There’s a “high likelihood” that cultural resources would be present, requiring future surveys, though some sites have limited access and impacts may be unavoidable, the report stated.
But what the Corps considers a cultural resource differs from tribal definitions. Katherine Pollock, the Corps’ Portland district archaeologist, said that fish, including salmon, are not legally a cultural resource. “That doesn’t mean we don’t care about them,” she said. “We do. They just get looked at from the biological perspective.”
Such a definition is “inappropriately narrow,” George said. Cultural resources comprise not just archeological objects. “They are steelhead. They are sturgeon. They are lamprey,” she said. They are a healthy river.
Last year, in late June, dredge pipes delivered a slurry of sand and water just a few hundred feet from the Columbia. Bulldozers flattened the pile into a settling pond about the size of a football field. Dan Robledo, the Corps’ project manager, gestured toward the massive gray mound — 300,000 cubic yards of sand freshly dug from the river, across from Kelley Point Park. A vessel blared its horn, and the single note echoed across the smooth silver water.
Over the years, the pile will amass more gritty girth. Some of the sand mountains along the river stand 60 feet tall. The shoreline resembled a construction zone, the early process of laying foundation.
For Robledo and others at the Corps, dredging the Columbia River is straightforward. Congress has charged the agency with a duty. The U.S. economy needs a deep river. “We have the mission to maintain the navigation channel to enable the use of this major transportation artery,” he said.
The Corps has deepened and channelized so many rivers across the country — the Sacramento, Columbia and Mississippi, among others — that the work has transformed the visible memory of what a river is, what it looks like and who it serves. Kelley Point, now a place where two large bodies of water meet, where differing paths converge, is deeply scarred by colonialism. Differing values imposed on the river have all but erased the cultural landscape. It has become just as difficult to remember a river’s true dynamic nature as it has to recognize its undoing.
The landforms built by the river’s sand — Sauvie Island and Kelley Point — still exist. The geologic ingredients for extensive marshes, where wapato once grew and canoes cut through the shallow, slow-moving water, are still present. The Tualatin Mountains’ navy ridgelines border the river, guiding it north as it has flowed since the volcanic rock blanketed the landscape. The river still bends and slows here, still has the potential for sand to spill out and build something new.
