Regional Approach Considered For Cape Cod Bay Shoreline Protection

Orleans, Brewster and Dennis together share a significant swath of the Cape Cod Bay shoreline. It only makes sense that the towns work together to help protect it from coastal erosion and the effects of climate change.

The Center for Coastal Studies utilized a state grant from the Office of Coastal Zone Management to develop a regional shoreline management plan designed to help the three towns collaboratively protect the 14.5 miles of shared coastal shoreline together.

The center has been exploring a regional approach to shoreline protection using the state funding since 2020, said Steve Mague, program director for the center’s applied science program. That effort began with a similar effort focused on the Outer Cape towns of Eastham, Wellfleet, Truro and Provincetown.

“If you buy into that concept that the shoreline doesn’t care about town lines, we wanted to come up with an approach that we could balance sort of the many competing and often conflicting uses of the coast by working together in unison with the natural processes along the shore,” Mague said during a presentation of the plan at the Dennis Police Department on June 17.

Mague said the long-term sustainability of the shoreline is dependent on the natural transport of available sand in the area. In most cases, upland sand allows natural renourishment of the shoreline.

“That is a critical part of the natural response to sea level rise,” he said. “What it does is allows the shoreline to adjust itself to changing conditions resulting from rising sea level, but it also helps in a different way as a storm control measure and a storm damage prevention measure for downdrift properties by supplying sediment.”

But across the stretch, Mague said, there are areas in which those natural processes are interrupted by seawalls and other types of infrastructure, which inhibits the natural restoration of the shoreline.

“What we’re doing is limiting the availability of sand to enter into the sediment transport system,” he said. “Walls are put in, different types of walls over the years, and what happens is that sand is bound up and protected by the walls. And what happens is the system is no longer receiving the same amount of sand it needs to sustain itself, particularly in the face of sea level rise.”

The center took an inventory of 44 parcels covering 16,000 cubic yards of shorefront that could be targeted for annual renourishment. Mague said that list was further narrowed to six sites, including Breakwater Beach, Mants Landing, Paines Creek and Spruce Hill on the Sea Camps property, all in Brewster.

Mague said the center’s goal was to create a shared framework for managing the shoreline between the three towns without instituting new policies or bylaws. The biggest “deliverable” to the towns, he said, is the creation of a shared online data portal giving town staff and residents access to detailed information about the current state of the shoreline from Chase Garden Creek in Dennis out to Rock Harbor. 

The portal includes features such as a coastal bank viewer, a beach nourishment estimator and a shoreline stabilization inventory. It also includes interactive mapping tools such as a salt marsh change viewer and a critical facilities map.

“So basically it is a repository of local-scale data, immersive education tools and useful online resources related to the Cape Cod Bay shoreline in Orleans, Brewster and Dennis,” said S.J. McFarland of the Center for Coastal Studies. McFarland added that staff in each of the three towns have the ability to update the portal with new information in real time. 

A regional approach to addressing the shoreline has many benefits, including the potential for cost savings. It also better positions the towns to apply for and receive state grants in support of protection efforts, Mague said.

Ronald Slowek, a member of the Brewster conservation commission, applauded the center for its work to help address the issue of coastal erosion regionally. The plan could prove particularly helpful to town staff and volunteers charged with addressing the problem. 

“No one has enough staff to do what we’re supposed to do, forget what we’d like to do,” he said. “I can see this as a way to maybe create some efficiencies and save on man hours and the limited time that they have.”

Others at the June 17 session asked about the potential for physically transporting sand from other sites to help in the renourishment efforts. But Steve McKenna from the Office of Coastal Zone Management said that could be easier said than done, namely because of how those efforts might adversely impact local fish habitats.

No details were given at the presentation about next steps. George Meservey, Orleans’ director of planning and community development, said in an email last week that the center has not outlined any “specific nourishment plans” for the town as of now, but agreed the data portal gives the town good information to work off of in support of future resiliency efforts.