USACE Proposes Maintenance Dredging of the Mianus River Federal Navigation Project

Posted 7/28/2015

Aerial view of Mianus River The Mianus River originates in southeastern New York, flowing southerly for about 20 miles before emptying into Cos Cob Harbor in Greenwich, CT. Photo taken Oct. 1967

The U.S. Army Corps of Engineers, New England District is proposing maintenance dredging of the Mianus River Federal Navigation Project in Greenwich, Conn.

The project consists of a 6-foot channel, 100 feet wide, running from Cos Cob Harbor up the Mianus River to a point about 400 feet downstream of the Boston Post Road Bridge, then, 75 feet wide to the bridge.

The proposed work consists of the maintenance dredging of about 60,000 cubic yards of primarily fine-grain clay and silt in order to return the Federal project to its authorized dimensions.

“The upper portion of the channel has shoaled into depths as shallow as – 4 feet Mean Lower Low Water across the entire width of the channel,” said Project Manager Jack Karalius, of the Corps’ New England District, Programs and Project Management Division in Concord, Mass. “The shoals are hindering navigational access and compromising vessel safety.”

The work will be performed by a private contractor, using a mechanical dredge and scows, under contract to the government. The dredge will remove the material from the bottom of the river and place it in scows which will be towed by tug to the Western Long Island Sound Disposal Site, about 6 miles away, where the material will be released.

Dredging is anticipated to take approximately 2 – 4 months between Oct. 1 and Jan. 31 of the year or years in which funding becomes available.

The town of Greenwich has requested maintenance dredging of the Federal navigation project. The river and harbor are used predominantly by recreational boats, and also several commercial fishing boats.

The last time the Mianus River was maintained was in 1985 when approximately 53,000 cubic yards of sediment was dredged and placed at the Western Long Island Disposal Site.

Source: Corps proposes maintenance dredging of Mianus River Federal navigation project in Greenwich