Project Summary: Sesuit Harbor, Dennis Dredging Project
Project Summary: Sesuit Harbor, Dennis Dredging Project:
This is an annual project for the town of Dennis, that due to the Winter Flounder Time of Year (TOY) restriction (a more detailed discussion will be posted soon on this most important topic) requires the dredging to be completed by January 31st.
The target volume was 13,278 Cubic Yards.
Note the gray areas in the pic below, these are the areas where the shoaling is most significant and dredging will be focused to clear the channel to its maintained depth of -6 feet at MLLW (Mean Low Low Water).
Mobilizing for this project began on December 31st when the County dredge Cod Fish II, the pushboat JW Doane and ~1,500 feet of pipe were moved from Pamet Harbor, Truro to Sesuit Harbor.
Once on site, it took several days into the new year to start the on-site work due to the cold temps and wind. On January 7th, the pipe was moved into position along the beach/discharge area but the next few days of wind/seas kept the Cod Fish II at the dock.
On January 12th, dredging started in the inner harbor area and continued on the 13th. Dredging didn’t resume until January 18th due to almost a week of strong winds/seas in Cape Cod Bay.
Dredging continued on the 19th and 20th and then a one day break due to strong wind/seas, with dredging resuming on January 22 continuing through January 25.
With the January 31st TOY deadline approaching, we still had a significant amount of dredging left and unfortunately the area that needed dredging the most was in the outer / approach channel where the seas this time of year prevent the Cod Fish II from dredging.
On the 27th, the Cod Fish II and pipe was moved to the outer / approach channel area (repositioning the dredge and shortening the pipe) and dredging continued late morning. Dredging continued on the 28th but with a blizzard forecasted operations stopped early afternoon to disconnect the pipe from the dredge and move the dredge back inside the harbor.
An extension was requested to the MA Department of Marine Fisheries and it was granted to allow for a few more days of dredging (only required for the inner channel – inside of the breakwater). Dredging resumed on February 2nd, and continued on the 3rd, stopping again due to wind/seas and resuming again on February 7th on the Approach Channel section and completing this area thus finishing the project.
A Post-Dredge survey was done on February 8th which is needed to close the project and determine the volumes removed.
As noted by the many weather interruptions throughout the month, the winds and seas that are generated shift the sand within the channel banks and in some cases backfilling the areas already dredged. The commercial and recreational importance of this harbor requires annual maintenance dredging, and unfortunately, due to the TOY restrictions requiring that dredging cannot take place after January 31st, the sand will continue to migrate in and out of the channel areas and in a few short months all of the dredging work completed will appear to be have never taken place once the season begins.
The Post-Dredge survey results will be posted once available.