EVERETT — Another round of dredging in the lower Snohomish River and Port Gardner has begun as part of the ongoing task of keeping the waterway safe for shipping.
The Army Corps of Engineers is spending $1.5 million on the job, scheduled to last through February. Some of the spoils — a term for dredged material — will be available for use by local governments, while some will be used to reinforce the shoreline along Jetty Island, said William Dowell, a spokesman for the federal agency.
Portable Hydraulic Dredging Inc., of Eagle Creek, Ore., is doing the work.
The company is using hydraulic machinery to suck out the sediment in two strategic locations in the river. Work began last week south of the I-5 bridge across the river, next to the Langus Riverfront Trail. Over the winter, the work is scheduled to be done in an area between the Port of Everett Marina and Jetty Island, just south of the 10th Street Boat Launch.
An estimated 21,000 tons in spoils from the upstream site will be stored on city of Everett property while 79,000 tons of sediment from the site near the marina will be used at Jetty Island.
These parts of the river are dug out about 20 feet deeper than the surrounding bottom to catch silt that flows down the river from the Cascade Range, not only preventing it from piling up there but lessening its accumulation in other parts of the channel.
“It’s better for the environment,” Dowell said.
Still, the sediment does collect in some places. In mid-November, crews will use a clamshell crane to dig out the sand in spots that need it, Dowell said.
Dredging has been done regularly in the river since 1910, Dowell said. The agency is responsible for clearing a channel that extends from the waterfront six miles up the lower Snohomish River. The Port of Everett has done other work on its own.
The Corps last dredged the river two years ago. Work was put on hold last year because of funding shortages, Dowell said.
“It’s done as often as we possibly can,” he said.
In the past, the city has used the spoils to raise the flood plain on vacant public land in the riverfront area, spokeswoman Kate Reardon said. This time, the material will be stored on city of Everett property and may be available to other government agencies for their use, she said.
Spoils have been used before to reinforce the beach at Jetty Island. The island itself was formed in part by spoils deposited from the early years of dredging, and more has been added over time, according to the Port of Everett. This time, about 65,000 tons are planned to be used to reinforce the beach at the south end of the island and 14,000 tons are targeted for placement to protect a saltwater cove at mid-island.
The silt is tested for toxins before it’s made available for use, Dowell said.
“It’s pretty pristine there in the Snohomish River, it’s very good material,” he said.
Art Kilander, owner of Portable Hydraulic Dredging, asks that boaters slow down and be cautious around the dredging work.
“If we are lifting an anchor and the boat is pulled down hard, you can even flip our big boats with your wake. Around working craft, you are responsible for your wake,” he said in a written statement through the Corps.
Bill Sheets: 425-339-3439; firstname.lastname@example.org.