The Dredge Report | Week of June 13, 2021
Sand Shifter – Saquatucket Harbor Channel, Harwich
With the Allen Harbor project completed, the second and last project for Harwich is Saquatucket Harbor. This is also our last project of the season.
This harbor is a very important recreational and commercial port for Harwich, as well as for all of Cape Cod as thousands of boats use this harbor each season and keeping the channel clear of shoaling is critical. The Pre-Dredge survey completed showed just over 12,000 Cubic Yards that needed to be removed to maintain a controlling depth of -9 feet at Mean Low Water (MLW) throughout the channel. Its important to point out that the Pre-Dredge survey covers the entire length and width of the channel and some areas are heavily filled in (the dark gray areas as seen in the below plans) while other areas are lightly filled in (the green soundings). The Blue soundings are areas that do not need to be dredged as they are equal or deeper than the -9 foot depth at Mean Low Water (MLW). Most of the dredging is focused on the gray areas.
The Pre-Dredge survey plan – the southern end of the channel
The Pre-Dredge survey plan – the northern/inner harbor end of the channel
Similar to Allen Harbor, this project will also have multiple locations for the disposal of the dredged sand (both private and public beaches). As dredging was planned to start at the southern end of the channel, the weather conditions (southerly winds & seas) on Monday were not suitable for dredging. Dredging started on Tuesday and continued on Wednesday. Dredging on the western disposal location was completed on Wednesday and 5,500′ of pipe needed to be moved.
This operation requires several steps; replacing the water/sand mixture in the pipe with only water, then capping off both ends of the pipe, then connecting a hose from a compressor (located on the beach) which then blows the water out of the pipe thereby raising / floating the pipe. Once floated, the pipe is then dragged off the beach and towed. In this case, the next disposal location is Red River Beach which is located on the eastern side of the Saquatucket breakwater.
Harwich Harbormaster John Rendon offered a great deal of assistance in managing the boat traffic and keeping the boats away from the pipe while it was being moved as both Saquatucket and Wychmere Harbors were effectively blocked during this process.
This entire process took only four hours which is extremely fast and is yet another display of the high degree of expertise by the entire dredge crew lead by Dredge Superintendent Jason Bevis.
The following pictures show some of the phases of the operation from the floating of the pipe to the restarting of the dredging on Red River Beach.
Every arrow points to a float attached to the pipe that is submerged soon to be floating.
Pipe starting to float.
Dredge Superintendent Jason Bevis overseeing operations from the deck of the Pushboat Stephen Bradbury
Pipe being towed off the beach enroute to Red River Beach.
Dredge crew working in skiffs aiding in keeping the pipe straight as its being towed.
Harwich Harbormaster’s patrol boat operated by Harbormaster John Rendon managing boat traffic while the pipe is being moved.
Deckhand Andrew DiPietro works on connecting the dredge pipe to the dredge.
The cutterhead being lowered to restart dredging operations.
