CHATHAM – Erosion has increased along Chatham Harbor between the fish pier and Claflin Landing, across from a new washover on North Beach Island, and Chatham Bars Inn is hoping to stave further loss of its beach with an infusion of sand dredged from nearby Aunt Lydia's Cove.
Changes along the stretch of shoreline began before the major washover blew out dunes and sent water cascading over the barrier beach and into the harbor in December, but the washover has exacerbated the erosion. The beach has retreated so much that Chatham Bars Inn guests have to wade thigh-deep in the water to access the inn's dock.
The area of the dock is one of three sections of the beach that the inn is asking to add additional sand above and beyond a nourishment permit previously approved by the conservation commission. The inn is requesting to add approximately 1,800 cubic yards of sand in an ellipse shape around the dock, as well as 500 cubic yards each to an area north of the dock in front of the Ludwig property at 308 Shore Rd. and an upper beach area landward of the dune at 295 Shore Rd. If approved, the additional beach nourishment will increase the permitted volume of sand that can be placed along CBI's beach to 7,500 cubic yards.
Because the sand around the dock would be placed below low water, it will require a Chapter 91 permit from the state department of environmental protection as well as approval by the Army Corps of Engineers. The dock was already extended landward once a few years ago. The distance now between the dock and the shore shows how much the beach has retreated, Charlie Argo of Coastal Engineering told the commission Feb. 24.
Between late January and early February, the area lost from three to six feet of dune, Argo said. Additional sand will buy time to get through the winter and spring, he said.
“If you don't place more sand in the area...other measures that may have to be more drastic may have to be taken,” he said. Because the area is mostly low dunes, beach nourishment is really the only short-term measure that can be taken to combat erosion.
“Beach nourishment is really the most environmentally friendly and efficient way of protecting the shoreline against ongoing erosion that is likely to continue at an increased rate as the barrier beach deteriorates,” Argo said.
“This is definitely sacrificial,” Coastal Resources Director Ted Keon said of the beach nourishment. “More will be needed in the future as things continue to deteriorate.”
A December storm knocked out dunes on the barrier island across the harbor from the inn, and several more recent storms have continued to whittle away at the gap. It remains a washover, however, with water flow into the harbor only on the incoming tide. Eventually it could deepen enough to become an inlet, which would have implications for the inner shoreline.
CBI is hoping to benefit from sand being dredged from Aunt Lydia's Cove. Once it completes its work in the Stage Harbor entrance channel, the Barnstable County dredge Sand Shifter is scheduled to head to the boat basin around the fish pier, according to Keon. But that depends on timing of completion of the Stage Harbor work, which has been going slower than anticipated. If it does happen, however, sand from the boat basin will be going to the beach at Linnell Lane in exchange for public strolling rights. If the dredge is able to get to the south side of the fish pier, it is likely to go to the CBI beaches, Keon said.
However, permits for the new CBI beach nourishment areas won't be in place by then, so the sand would be placed where currently permitted, in a narrow strip between the dunes and high tide line, Keon said.
If sand is not available from dredging, CBI may seek other sources, Argo said. If so, compatibility analysis would be conducted in adherence to DEP guidelines.
The most significant impact of the additional nourishment would be to the area around the dock, which is identified as a blue mussel habitat. No mussels were observed during recent inspections, Argo said, and Shellfish Constable Rene Gagne said the additional sand might enhance shellfish habitat in the area.
The commission was expected to vote on the amendment to CBI's beach nourishment permit on Wednesday.