MARYSVILLE — More than a century ago, federal surveyors who made notes about the Snohomish River delta recorded comments about marshy areas of cattails interspersed with small forests of Sitka spruce, cedar and salmonberry shrubs.
In the ensuing years, the estuary was extensively diked and gated to create farmland. Most of the wetlands, which provided a place for juvenile salmon to eat, grow and acclimate to salt water, were lost.
Now some of that habitat is on the verge of being restored. The U.S. Army Corps of Engineers has given a final go-ahead to a plan to remove dikes and tide gates to allow salt water from Possession Sound to mingle with fresh water from Ebey Slough.
The Qwuloolt project — the word means “large marsh” in Lushootseed, the Coast Salish language spoken by local Indian tribes — aims to restore 360 acres south of Marysville to its original state.
The Tulalip Tribes are leading the $8.8 million project, with nine local, state and federal agencies serving as partners. Most of the money is coming from federal grants, the rest from the state and in-kind contributions, said Kurt Nelson, environmental division manager for the Tulalip Tribes.
Only about 18 percent of the original 10,000 acres of wetlands in the entire delta — of the type Nelson said was recorded by the surveyors — remains, he said.
“If we can increase that amount it could provide a pretty big jump start for salmon restoration,” he said.
The Qwuloolt project will be the largest restoration in the delta to date. A smaller project by the city of Everett, about 60 acres next to the city’s water pollution control pond along I-5, was finished in 2007. Another about the same size at the south end of Spencer Island was done by Snohomish County in the 1990s.
The Qwuloolt project represents only a small area of the original wetland, but other projects are being studied or planned. These include one by Snohomish County to restore 300 to 400 acres on Smith Island and a plan by the Port of Everett to restore much of the area between Union and Steamboat sloughs. A large area south of U.S. 2 is being studied by the state.
It’s hoped the $11 million Snohomish County project can begin in 2012 or 2013, said Debbie Terwilleger, director of the county’s surface water management division.
A 10-year Snohomish River Delta salmon restoration plan — developed shortly after the Puget Sound chinook salmon was listed as threatened under the Endangered Species Act in 2005 — calls for 1,200 acres of estuary to be restored.
In the Qwuloolt area, the Tulalip Tribes have been buying property for more than 10 years, Nelson said. Much of the rest is owned by the city of Marysville.
The tribes have carved 2 miles of new stream channel to help distribute the water when it comes and have filled in a mile of farming ditches.
Late this summer, a new dike is to be built along the west side of the property, said Bernie Hargrave, a restoration program manager for the Army Corps of Engineers in Seattle. This will protect the Marysville Wastewater Treatment Plant and other parcels from flooding when the old dike is breached.
Tide gates at the mouths of Allen and Jones creeks will be removed, allowing salt water — and salmon — to move upstream.
Tide gates are pushed shut by the salt water at high tide and then reopen as the tide runs out. This provides only a narrow window of time for fish to get through, Nelson said.
With the tide gates gone, fish will be able to go as far as 16 miles up Allen Creek.
The final piece of the puzzle will be to substantially lower and breach the dike along Ebey Slough on the south end of the property, expected to be done in 2012, Hargrave said.
Marysville is considering building a trail along the north side of the property and has purchased land in Sunnyside for an overlook. The city does not currently have money to develop it into a park, but “it’ll happen eventually,” Mayor Jon Nehring said.
Once the water flows into the Qwuloolt area, it will take a while for the site to readjust, Nelson said, and for marsh-type plants such as cattails to establish themselves.
“We expect the site to evolve,” he said.
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