Wednesday September 16, 2026
KGW8 —
In order for massive cargo ships and tankers to traverse the Columbia River up to Portland, crews spend up to eight months each year dredging the river bottom so the channel remains deep enough for the commercial ships to pass.
The dredging is a massive operation that most people never see. But the work could come at a cost; local tribes have been warning for decades of the impact it can have on native fish habitats.
The Columbia River is among the Northwest’s most important trade routes, commonly called a “marine highway.” And underneath that traffic, the river is constantly changing.
As sediment build up on the river bottom, crews with the vessel Dredge Oregon work every year to dig it out, keeping the channel excavated just enough for shipping vessels: 600 feet wide and 43 feet deep.
“This is dredge season,” said Don Tjostolvson, director of navigation for the Port of Portland. “You don’t really notice the dredging that much, but you would notice it really quick if we didn’t do it.”