Mitigating erosion needs a multi-step approach, says Saco shoreline group
SACO — There’s no one single fix-it for mediating erosion from the Saco Bay Jetty. Combatting erosion is going to take a multi-step approach.
That was one of the messages on Saturday from a panel of local experts and policy makers at an informational meeting hosted by community group SOS Saco Bay at Ferry Beach Retreat and Conference Center.
The Saco Bay Jetty stretches out 6,600 feet into the ocean of Saco Bay from the mouth of the Saco River. The jetty was authorized by President Abraham Lincoln to help keep a navigation channel in the Saco River clear. It was completed in the 1880s and has been modified three times over the years.
Although Lincoln had good intentions when authorizing the jetty, the side effect of the structure is coastal beach erosion, caused by wave energy reflecting off the jetty and displacing sand.
Over the years, the beach in the Camp Ellis neighborhood next to the jetty has shrunk, and houses and streets have been washed away.
“Camp Ellis beach has not gotten new sand from the Saco River since 1910,” said Peter Slavinsky, marine geologist from the Maine Geological Survey. “Since 1910 it’s been eroding. It’s been eroding at about a rate of three to four feet per year.”
Over the years, the beach erosion has been creeping north, and Slavinsky said it has reached the Ferry Beach area, and a seawall near Ferry Beach has helped stop erosion from spreading further north. State law generally does not allow the construction of new seawalls, but Slavinsky said the planting of dune grass just north of the sea wall has helped protect that region of Surf Street.
The sand that gets taken from Saco ends up across the bay at Pine Point in Scarborough, said Slavinsky.
In 2006, the federal government appropriated $26.9 million for a project to mitigate erosion caused by the jetty. The money, however, has not been authorized for expenditure and a project has not been approved.
City officials are hoping that the decades long dream of a mitigation project may come true.
After review of several options, the Army Corps has expressed its preference for an erosion mitigation project. The Army Corps has proposed a project that would create a 750- foot spur jetty off the side of the main jetty that would run parallel to the shore. The proposed spur would be created with 20 ton “Volkswagen-sized” stones, said Saco Shoreline Commission member Rick Millard.
The City of Saco has been in correspondence with the Army Corps and is hopeful to get a draft of a project partnership agreement in January. The project partnership agreement, if approved would be a legally binding contract between the federal government and the city of Saco for the construction of the proposed project.
The proposed project would also require beach replenishment – about 350,000 cubic yards of sand, said Millard. Should the project move forward under the $26.9 million budget, there won’t be enough money left over after construction to properly replenish the beach afterwards and there will be no money for periodic beach replenishment in the future.
“Just building a rock jetty will not be a solution, because there is no sand to trap,” said Slavinsky. Bringing in sand is going to be a key component in maintaining Saco’s beach, he said.
The Saco River was dredged in 2019, and sand from the dredge – an amount less than 100,000 cubic yards- was dumped on the Saco coast. This created the widest stretch of beach seen in years. Now, two years later, the benefit from the replenishment has all but disappeared from Camp Ellis alongside the jetty, and the sand has moved north.
This shows that sand replenishment can help maintain a beach, as long as there is a way to slow down how fast it travels north, said Slavinsky.
Peter Hanrahan, of Hanrahan Environmental, suggested the city explore ways to use living shorelines, incorporating natural elements to protect the shoreline. He referred it as an offensive strategy and not a defensive strategy.
“We work with nature as a partner, not as the enemy,” he said.
The living shorelines approach uses wave attenutation devices, or WADS, which Hanrahan said have less of a negative impact on the natural habitat than other artificial barriers. The WADs, which are hollow structures with holes on the sides, divert wave energy and create an artificial reef that promotes aquatic wildlife, he said.
State Representative Lynn Copeland of Saco recently had legislation passed that directs the governor to take actions to assist and support Saco in the city’s role as a non-federal sponsor of the proposed mitigation project with the Army Corps.
Slavinsky said since this legislation has been passed, there have been “minor discussions” with the Army Corps of Engineers with regional sediment management. He said every ten years, Scarborough is dredged by the Army Corps, and much of the sand removed originated from Saco. In, 2015, 130,000 cubic yards of sand was removed during a dredge in Scarborough River and was placed on Western Beach in Scarborough, said Slavinsky. He said, typically, the Army Corps takes the less expensive approach when dumping the sand, but if a regional sediment management plan could be approved, it would mean at least some of the sand from Scarborough would get delivered to Camp Ellis.
State Senator Donna Bailey was a co-sponsor of Copeland’s bill. She said she is working to get a state grant for a $20,000 study regarding the feasibility of wave attenuation devices in Saco Bay. She said she is also working with York County Commissioners to get approval to use American Rescue Plan funds for dredging equipment that could be used county-wide.
“None of these are the solution, they are all part of the solution,” she said.
Publisher Liz Gotthelf can be reached at [email protected].