No Way Out: Chatham Harbor All But Boxed In By Shoaling

By: Alan Pollock

Topics: Erosion , Dredging

An aerial view of Chatham Harbor, looking north. The North Cut is at the top right of the image. COURTESY KARL SWENSON

CHATHAM For vessels over a certain draft, getting in and out of Chatham Harbor is now impossible except during the most favorable tides.

While smaller boats can still pass freely, commercial fishing vessels and even Coast Guard rescue boats are increasingly unable to leave the harbor.

Experts say the south inlet opposite Outermost Harbor is predominantly feeding Nantucket Sound through the so-called Fool’s Cut, with little tidal flow to Chatham Harbor. The North Cut by Minister’s Point provides good tidal flow with Pleasant Bay, but a shoal just inside the inlet is now severely limiting access to the south. In between, Chatham Harbor has comparatively little tidal flow, engineer John Ramsey said last Thursday in a presentation of early findings from a study of the town’s east-facing waterways. Without adequate water velocity to flush it away, sand from the outer beach tends to fill the harbor entrance channels, he noted.

The study, conducted by Applied Coastal Research and Engineering and the Provincetown Center for Coastal Studies, is yielding other preliminary findings that are troublesome for Chatham Harbor. North Beach Island is rapidly collapsing because of a lack of sand coming from the north.

“This beach is being starved. It’s being starved very rapidly now,” Ramsey said. The island is migrating south and west, and while it will not likely disappear, it will generate more shoals in the harbor. The ocean will increasingly wash over low parts of the beach during storms, leaving some mainland beaches newly vulnerable to ocean waves, he said.

North Beach Island “will eventually join onshore at some point, and actually form some pretty nice protective beaches,” Ramsey said. “But it’s going to be kind of a painful process getting there.”

Bill Holland, who supervises the charter boats at Chatham Bars Inn, said they frequently use the North Cut.

“What do you see happening in the next year with that channel?” he asked.

“This is the million dollar question,” Ramsey said. It is a difficult thing to maintain the harbor access channel just inside the inlet. “It is closed off. So there is really no way out,” he said. The town obtained emergency permission to dredge this area last winter, but deteriorating weather conditions kept the work from being performed.

“That channel’s not going to open by itself,” Ramsey said.

Aunt Lydia’s Cove Committee Chairman Doug Feeney, a commercial fisherman, said there is now less than four-and-a-half feet of water at peak high tide in the channel leading to the North Cut. That means that the fleet needs to leave as a group at high water, and must time their return for high tide, or be locked out.

“We can’t just fish high tide to high tide, because it’s a safety issue,” Feeney said.

Chatham Coastal Resources Director Ted Keon said this week that the town is still seeking permission to conduct dredging in the area inside the North Cut, previously authorized for emergency dredging. Minister’s Point property owner Gerald Milden has filed suit in Barnstable Superior Court against the town of Chatham and the conservation commission, claiming it wrongly permitted a potential future dredging project in that location. Milden has argued that previous dredging in Chatham Harbor caused a change in currents that undermined the seawall protecting his property, leading to its partial collapse last year. With the commission’s order of conditions under appeal with the state department of environmental protection, the permitting process has stopped, Keon said.

“We can’t be held up in court over some nonsense,” Feeney said. While he understands the concerns of waterfront property owners, “the Chatham fishing fleet has been here since the beginning. Homeowners have not,” he said. The Chatham fleet is now largely at Saquatucket Harbor, fishing for monkfish and skate, but it will be forced to return to Chatham in the spring for the skate and dogfish fisheries. Feeney has asked selectmen to act immediately to schedule a discussion about the navigability of the harbor. There must be some solution that will allow Chatham Harbor dredging to proceed, he added.

“This is how I feed my child,” he said.

If a dredging project clears the court, it is unclear whether it could be conducted in the limited windows of time between state restrictions designed to protect certain fish species. Keon said town officials have inquired with the state Division of Marine Fisheries about possibly obtaining relief from those rules.

While Milden blames the collapse of his revetment on dredging, information presented by Ramsey seems to indicate that the increased currents around Minister’s Point are more likely related to the evolution of the barrier beach offshore.

Using long-term tide data and sophisticated computer modeling, researchers estimated tidal velocity throughout the harbor region and identified key changes related to the decline of the southern inlet and the widening of the North Cut. In 2007, incoming tides were more dispersed, but by 2018, a deep curvy channel had formed bringing most of the Pleasant Bay flow just north of Minister’s Point to the North Cut, creating currents of around six knots. By comparison, the typical maximum flow in the Cape Cod Canal is just under five knots.

Meanwhile, tidal velocity decreased over time through the South Cut, as sand from North Beach Island caused the inlet to constrict and move southward. The modeling shows swift flood tides coming through the inlet and through the Fool’s Cut, with very little water passing back north during ebb tide, thanks to the tidal differential between the ocean and Nantucket Sound.

The study also modeled wave patterns coming from a typical northeasterly coastal storm. In 2007, the highest waves came ashore at Lighthouse Beach, and to a much lesser degree, at Minister’s Point during incoming tides. Models from last year show heavier waves reaching the vicinity of Outermost Harbor through the Fool’s Cut, and at Minister’s Point during all phases of the tide. The waves predicted by the computer models were not huge, Ramsey noted.

“We’re looking at about four-and-a-half-foot waves during a northeaster that are hitting the shoreline. But again, that’s something that needs to be dealt with,” Ramsey said. “It’s something that that area – especially some of the sandy shorelines – have not dealt with in 150 years.” Additional areas on the east-facing mainland shore will be vulnerable as North Beach Island continues to degrade, he added.

The $242,000 study, funded mostly by the state’s Office of Coastal Zone Management with a $60,000 contribution from the town, is only in its early phases. Future work will use the computer modeling and predicted changes in land forms to help suggest shoreline management strategies.