EVERETT — A massive earth-moving project to transform low-lying farmland along the Snohomish River delta into salmon habitat could break ground in August, after more than a decade of preparation.
Snohomish County’s Smith Island project would flood about 350 acres now protected by dikes. State and federal agencies consider it a vital piece of the strategy to revive Chinook salmon stocks in Puget Sound. They have supplied grants to cover most of the $26 million cost.
The county’s Public Works Department is accepting bids this month from contractors to perform the bulk of heavy construction.
“The bid now is the majority of the work building the new infrastructure, the new dike and drainage system,” said Steve Dickson, a public works special projects manager.
The new dike will stretch for more than a mile. It will sit farther from the water than the existing dikes, built in the 1930s, and play an important role protecting I-5 and Everett’s sewage treatment plant from floodwaters.
After the new dike is built, the county plans to issue another bid to breach the old dikes and excavate channels that would allow water to flow from Union Slough.
That work is projected to finish in 2016 or 2017, Dickson said. The habitat is expected to regenerate gradually, over several years.
The Smith Island project stems from the federal government’s 1999 listing of Puget Sound chinook salmon as threatened under the Endangered Species Act.
A 2005 recovery plan for the Snohomish basin set out a goal of restoring 1,200 acres of estuary.
That’s a big piece of the 7,000-plus acres of Puget Sound estuary the state hopes to restore by 2020. If the Snohomish River projects succeed, they would eclipse the 900-acre restoration project on the Nisqually River delta, now the largest salmon-habitat restoration effort in the state.
“For chinook salmon, restoring the estuaries is one of the most critical things you can do,” said Jeanette Dorner, director of salmon recovery programs for the Puget Sound Partnership, a state agency. “If the estuary habitat is limited, it limits the overall abundance of chinook that can come back.”
Other projects in the Snohomish basin include the Tulalip Tribes’ Qwuloolt Estuary restoration project, roughly a mile and a half from the county’s Smith Island project. It seeks to restore about 350 acres of tidal marsh and forest scrub-shrub habitat that had been cut off by levees and choked with invasive reed canary grass. The Tribes started major work in 2012 and hope to finish this year.
The Port of Everett’s Blue Heron Slough project is underway to restore tidal wetlands on 350 acres that used to be Biringer Farm.
“To increase the number of chinook being produced in the Snohomish would have a significant effect in Puget Sound, for economic, ecological and cultural reasons,” said Kurt Nelson, who is managing the Qwuloolt project.
Only about 17 percent of the Snohomish River’s historic 10,000-acre estuary remains intact as fish habitat, Nelson said. That creates a bottleneck that interferes with survival.
“These are locations where they (juvenile salmon) can feed on forage and prepare themselves for marine conditions,” he said. “If they can grow better in the estuary, it gives them a better chance of survival when they reach the marine water.”
Other nearshore marine species, such as starry flounder, also should benefit from the restored habitat. So should waterfowl.
The Smith Island project has worried neighboring landowners from Diking District 5. Specific concerns include construction traffic on roads near Dagmar’s Marina, Buse Timber’s ability to float logs in the river, and saltwater degrading the soil at Hima Nursery.
In March, the county amended an agreement with the businesses. It gives the county’s assurance that drainage systems on the dry side of the dike will function as intended. It also commits the county to monitoring Union Slough higher sediment levels.
The group also questions whether dike construction would threaten an underground gas pipeline on Smith Island that belongs to Puget Sound Energy. The utility has reviewed the county’s designs and has consented to the dike being built above the pipeline, Dickson said.
To get going, the Smith Island project still needs permits from the county and the U.S. Army Corps of Engineers.