Massachusetts’ largest-ever estuary repair project — at the Herring River in Wellfleet — is taking some big steps forward.
A construction crew has begun assembling metal trusses for a temporary bridge to allow vehicles to pass over the river. The Chequessett Neck Road dike, which has choked the river of tidal flow for more than a century, will be removed.
The temporary bridge will probably be operational in early to mid December, said Geoffrey Sanders, chief of natural resource management and science at the Cape Cod National Seashore.
“That's a big step,” he said. “It's exciting.”
The town of Wellfleet and the National Park Service are collaborating on the Herring River project, which aims to restore 890 acres of intertidal wetlands. Estimates of the project cost range from $60 million to $70 million.
At Chequessett Neck Road, a new bridge will be built, with adjustable tide gates to allow significantly more salt water to move upstream.
North of the bridge, the project involves removing freshwater plant species, leveling human-made berms of land, and other work, to make way for a healthy salt marsh.
Sanders said phragmites — invasive reeds — need to be cut at just the right time. The inflow of salt water will kill many of the roots. Once that’s done, the project will plant spartina, “which is the salt marsh cordgrass that we want to see there,” he said.
In addition to the tide gates on the Herring River, the project includes construction of smaller water-control structures, including one at Mill Creek, a tributary to the Herring River, to prevent high tides from flooding private property once the tides return.
The National Seashore announced Tuesday that it has awarded a construction contract for the Mill Creek structure.
Both structures — Mill Creek, and the primary one at Chequessett Neck Road — are scheduled to be complete in 2025.
