It will take about a month to move 50,000 cubic yards of silt and deepen the channel in the Housatonic River.
It took more than a decade to dredge through the process of making it happen.
“For 13 years we’ve been working on this,” Bill Rock, chairman of the Stratford Waterfront and Harbor Management Commission, said.
Finally, with the Stratford Waterfront and Harbor Management Commission as lead agency, working in coordination with the U.S. Army Corps of Engineers, the river will be dredged, with work scheduled to begin by the end of October.
The Housatonic was last dredged in 1976.
Three areas in the channel between Stratford and Milford will be dredged: the mouth of the river, beyond the breakwater; at the bend across from the Birdseye boat launch; the bend from navigation buoy 19 to just south of the Washington Bridge into Devon, buoy 23.
“That’s a fairly long stretch, and the worst silting is in that area,” Rock said. “In some areas it’s 2 feet, down from 18 feet.”
While the depth will be increased in some areas in the channel, the gradient of the slopes on either side will not be changed.
Silt will essentially be vacuumed off the river’s bed by the Currituck, a boat owned by the Army Corps of Engineers. Dredged material is gathered in the hold of the boat, which then sails to a designated deposit area.
Material dredged from the Housatonic River will be dropped into the Long Island Sound about one-half mile off Long Beach. Incoming tides will help the sand “nourish” the beach at Long Beach, Rock said.
Federal and state agencies have both tested the silt that will be dredged and found it to be pure and free of pollutants, Rock said. Testing went so far as to make certain the size of the grains of sand in the dredged material matches the grains on the beaches.
Testing, and the related costs, were among the major drags on the project, stretching it out since the 1990s.
The need to dredge the river became evident when barges hauling fuel oil to the Devon power plant ran aground. They then had to wait 12 hours through the tide cycle to continue.
One of the top priorities of the Army Corps of Engineers is commerce, so it reviewed the situation, Rock said. From the power plant to the mouth of the river, 650,000 cubic yards of silt would need to be removed, at a cost of $13.5 million.
Baird Inc. did some dredging in 1997 and 1998, Rock said, but those permits expired.
The Army Cops or Engineers tested the silt from 1999 to 2001, again determining it was “virtually clean sand,” Rock said.
Stratford’s Waterfront and Harbor Management Commission began to discuss dredging with the Corps of Engineers and U.S. Rep. Rosa DeLauro (D-3rd) in 2001. However, no suitable site to deposit the dredging on land was found.
That began a search for a location to place material dredged from the water. One idea floated was using it to restore the beach at Hammonassett State Park. The cost of taking the material by barge was deemed too much. The former Army Engine Plant and beaches in Milford and Stratford were considered, but rejected.
What was then the state Department of Environmental Protection insisted on its own testing of the silt, Rock recalled, slowing the project. Each new set of tests brought with it new costs the towns and the state did not have the funds for.
As time and tide flowed on, silt continued to build up in the channel until dredging was approved by calling the buildup a menace to navigation.
The site where the material will be moved in the Long Island Sound had to be similar to the silt itself. Vegetation, rocks and oyster beds could not be buried, Rock said.
Funding was finally obtained with $750,000 from a $5 million bond via the state Department of Transportation.
More than 30 days from its arrival, the Currituck will fill its hold with 250 cubic yards per trip, sail to the designated point and open its hull, dropping the sediment to the sound. Officials hope the tide washes the sand onto Long Beach.
The end of the Housatonic, between Stratford and Milford, is the end of Connecticut’s second longest river at 149 miles. From its source in the Berkshires it falls 1,400 feet, and discharges 5,000 cubic feet per second at the mouth.