Cotuit dredging project finally done

The western end of Sampson’s Island (adjacent to Cotuit) was dredged by the Barnstable County over a three-year period from 2018 to 2020.

Over 135,000 cubic yards of sand was removed and piped to the eastern end of Sampson’s Island (Dead Neck). Since this project was completed in 2020, erosion and longshore drift continued moving sand from Dead Neck and collecting it at the western end of Sampson’s Island (Cotuit).

Several major early winter storms in December and January (of 2022 & 2023) breached a section of the island adjacent to the eastern jetty at the Osterville entrance to West Bay removing a high volume of sand creating a wash-over area making it vulnerable to future wash-overs during extra ordinary high tides.

This area of the island is also the nesting habitat for threatened coastal shorebirds including Least Terns, Common Terns and Piping Plovers.

The Cotuit Dredging Project started in the spring of last year but weather delays slowed the progress and the project was suspended on April 1st when the shorebirds arrived on the island. The project was restarted in October and it was completed on December 21st.

This was a very challenging project with over 2.1 miles (or 11,000′) of pipe required. A Booster Station (pump and engine) was also required due to the distance to the east end of the island where the sand was needed. In addition, some sections of the channel had very hard packed material which also slowed down the pace of dredging.

The project had several benefits. The first two were the dredging of the channel to remove shoaling, and the secondary benefit was placing the sand dredged from the channel to rebuild the ‘wash-over’ area.

Besides improving the coastal resilience of the eastern end of the island, all of the material dredged helped restore the critical nesting habitat for shorebirds (Piping Plovers, Least & Common Terns).

In addition, as the dredging removed several hundred linear feet of the western end of Sampsons Island, it also widened the area between the spit and the mainland thereby increasing the water flow or flushing of the Cotuit Bay.