The project will dredge the 15-foot channel, 125 feet from Long Island Sound up to the railroad bridge, then 100 feet wide up to Route 1 — the Mystic River Bascule Bridge. North of the bridge, a 12-foot channel will be dredged to the upper wharves at the Seaport Museum.
In addition to the channel, a 9-foot by 8.5-acre anchorage in the harbor north of Mason’s Island will be dredged, as well as a 9-foot turning basin above the railroad bridge.
The channel above the bascule bridge has not been dredged in 73 years. The remaining project features were last maintained in 1957.
The dredging is taking place because last year the state’s Bond Commission approved $5.5 million for the dredging of some shoaled areas of the Mystic River, notably near Mystic Seaport.
The funding was part of a larger $21 million package for dredging throughout the state.
Because the state is paying, they have also arranged for the dredging of two non-federal channels. Both are 6-foot navigation channels located north of Masons Island.
Had the state not contributed the funding, the project would be in limbo until federal funds became available.
Army Corps project manager Jennifer Flanagan said the project has the proper permits and confirmed the work will begin in October. Flanagan said the dredging would restore the channels and anchorage area to their authorized depths.
“No one objected during the public comment period,” Flanagan said. “The people we heard from were happy it was getting done.”
According to Flanagan, the dredging would restore the channels and anchorage area to their authorized depths. About 250,000 cubic yards of mostly silt will be dredged in the federal channel, while the state dredging will excavate an additional 30,000 cubic yards.
Dredging and disposal will take place during the period from Sept. 1 through April 1. The portions of the channel north of marker RN-22, adjacent to Ram Point, would be dredged from Sept. 1 through Jan. 31, while the portions of the channel to the south would be dredged from Sept. 1 through April 1.
A mechanical dredge using various types of clamshell buckets will remove material from the shoaled portions and place it into scows that would be towed to either a disposal site in Long Island Sound off the coast of New London, or a secondary site in Rhode Island Sound. The New London site is located 3.5 miles south of Eastern Point in Groton.
“At this point it looks like everything is in order and we’ll be ready to start in the fall,” Flanagan said.