Solutions proposed to stem erosion at Merrimack River’s mouth
PLUM ISLAND — On the northernmost shoreline of Plum Island where the Merrimack reaches the Atlantic Ocean, erosion has steadily eaten away at the protective dune that separates dozens of homes from the sea.
Erosion in this 300-yard-long stretch of the Merrimack River has gotten so bad that some homeowners fear they are just a few storms away from losing their houses. Just 3 years ago, the protective dune was 200 or so yards wide in this area; now it is less than 50 yards wide in some spots.
Homeowners along Plum Island’s Reservation Terrace, in the Newburyport end of Plum Island, have been lobbying hard for relief. They are hoping that local, state and federal governments will work together to dump sand in the eroded area in order to protect the homes.
At a meeting of the Merrimack River Beach Alliance Friday on Plum Island, government officials and local residents discussed the possible solutions for the erosion.
There are three solutions on the table:
- Piscataqua sand: The Army Corps of Engineers is planning to dredge the mouth of the Piscataqua River off Portsmouth, N.H. Some 680,000 cubic yards of sand is expected to be dug. About half of that sand could be dumped off Plum Island and Salisbury Beach, and the rest would go to Nantasket Beach and Scituate, according to Ed O’Donnell of the Army Corps of Engineers. It’s possible that some of that sand could be dumped at Reservation Terrace. But the project doesn’t have a green light right now, O’Donnell said. And it’s not clear who would pay for the cost of dumping. Local officials are applying for funds from the federal government to pay for it.
- Merrimack sand: The mouth of the Merrimack River is anticipated to be dredged in the near future. That sand could also be used. The problem is the cost of dumping it into the Reservation Terrace erosion area. Typically, dredge sand is dumped in “near offshore” areas along the coast, where the sea gently pushes it back up onto beaches. But to get it into the reservation terrace erosion zone requires a much more vigorous and expensive process. Officials are trying to find state and federal funds to pay for it, but it’s expected that the local communities will also have to pay a significant share. the cost isn’t known yet.
- “Captain’s Fishing” sand: The popular Captain’s Fishing Parties and Cruises business operates charter boats from a dock at the northern tip of Plum island, and the owners are expected to dredge their dock and mooring areas in March. That sand could possibly be placed in the Reservation Terrace zone, which is about a quarter mile downstream from Captain’s dock. Officials are looking into it.
Also, a new potential source of funds for erosion control is being pursued by state Sen. Katie O’Connor Ives, D-Newburyport, and Rep. Jim Kelcourse, R-Amesbury. They are seeking approval from the state Legislature to place a surcharge on the price of parking at the parking lot on northern end of Plum Island, and the funds raised would be used for erosion control. The lot is owned by the city of Newburyport, but the money collected by the surcharge would be used to bolster the nearby dunes that are owned by the state, thus the need for the state Legislature to be involved.
O’Connor Ives said it’s not clear yet what the per-car cost of the surcharge would be. The surcharge idea is similar to one that has been in place just across the Merrimack River, at the Salisbury Beach State Reservation. A $2 per car charge is assessed, and the money has been used for a wide variety of purposes such as repairing boardwalks and erosion control.
“We’d like to replicate what we’re doing in Salisbury,” said O’Connor Ives. “It’s functioning. It works.”
“We need this fund to start collecting money the day we open the parking lot,” said Newburyport Mayor Donna Holaday. The lot typically opens around Memorial Day weekend.
What caused the erosion
Erosion on Plum Island has been a longterm problem. As early as the 1820s the government has tried to engineer solutions to control it. But typically, each solution creates new problems.
The culprits behind the most recent spate of erosion are the stone jetties at the mouth of the Merrimack. The two massive structures — one on Plum Island and the other on Salisbury Beach — help to hold the location of the river mouth in place and are designed to create a funnel effect that, in theory, clears out a channel that allows for safe navigation into the river.
Three years ago the stone jetties underwent a $20 million renovation that repaired massive gaps, thus improving their ability to funnel water out of the Merrimack. But that funneling action has also pulled tons of sand off the northern end of Plum Island, in an area adjacent to the Plum Island jetty.
One of the reasons why the jetties were repaired was because it was believed that the gaps in them caused erosion further down Plum Island beach. Some of that erosion appears to have been abated by the jetty repair, but now the erosion problem has moved to a new location.