Posted on October 25, 2016
By Peregrine Frissell, greenwich time
Everyone is ready to start dredging the Mianus River except Mother Nature.
The project is finally set to begin “whenever the weather next allows,” said Mark Jackson, president of Coastline Consulting, one of the firms working on the project.
Contractors were hoping to begin Friday, but with the rain Friday, they said Monday looked like the most likely start date.
“Marine forecast is a tricky thing,” Jackson said. “You never know, sometimes the waves die down.”
About 50,000 cubic yards of silt is expected to be removed from the channel of the river in Cos Cob Harbor by Christmas.
“The entire dredge window, due to environmental constraints and restrictions, runs from Oct. 1 to Jan. 31, so hopefully he’ll be out of there by the end of December,” said Jack Karalius, the project manager with the U.S. Army Corps of Engineers.
The length of time it takes to complete the project will depend on weather cooperation and equipment, Karalius said.
“Most dredging is done in the middle of winter because that is the least amount of biological activity,” Karalius said.
Karalius said poor weather, particularly wind, makes it difficult for a scow to haul dredged material out to the dump site in the middle of western Long Island Sound.
Another possible disruption to the work could be caused by lobster pots currently in the work zone.
At a Greenwich Harbor Management Commission meeting Wednesday, Commissioner Frank Mazza said there were three individuals with lobster pots on the edge of the channel that had yet to move them.
The pots were just south of the I-95 bridge, Mazza said, just downstream from where the work is scheduled to begin.
“This is an issue that has been going on probably in Greenwich for ten years,” Mazza said. “Otherwise, everything else is a go right now.”
Karalius said the Corps had been in touch with the owners of the pots and is working to get them moved before they cause a delay in the project.
“We’re hoping they are going to be removed,” Karalius said. “We’ll just figure out what our options are when we get there if they are not moved.”
Karalius said it could take about a month for the dredging work to reach that point in the channel, but cautioned that that was only a rough estimate.
The busy channel, traveled by recreational and commercial boats, was last dredged in 1985, when 53,000 cubic yards of sediment were removed.
In recent years, boaters have complained that so much silt has built up, the channel is barely passable in sections at low tide, and boats frequently scrape mud and debris on the bottom.
The project will restore the channel to its authorized dimensions of 6 feet deep and 100 feet wide, running from Cos Cob Harbor up the Mianus River to about 400 feet downstream of East Putnam Avenue. From that point to the road, the channel would be 75 feet wide.
Jackson’s team, which was contracted by the Corps to work on the project along with Massachusetts-based Patriot Marine, will start at the northernmost end of the channel and work its way down.
The contractor will use a mechanical dredge to scoop the sediment, mostly fine-grain clay and silt, and place it on scows. Tug boats will then tow the scows about eight miles to the Western Long Island Sound Disposal Site, where the sediment will be dumped.
Source: greenwich time
