BY DYKE HENDRICKSON
---- — Town officials and emergency crews yesterday began shoring up vulnerable portions of Plum Island as dozens of large sandbag-like units were created in an attempt to halt erosion and stem damaging tides.
Before nightfall, workers had laid approximately one-third — or 100 linear feet — of the industrial-type sandbags and were expected to return to the beach this morning to continue working.
The focus yesterday was primarily in front of 37 and 35 Annapolis Way, two of the houses most severely undermined during Thursday’s nor’easter.
Homeowners in the erosion-affected areas will pay a total of $120,000 to $140,000 for the bulky “sand envelopes,” said state Sen. Bruce Tarr, R-Gloucester, who heads the Merrimack River Beach Alliance.
About a dozen homeowners from Annapolis Way and south along the beach will contribute to this fund, town officials said.
The town of Newbury will pitch in $10,000 for engineering costs to supervise this project and to improve anti-erosion measures, Tarr said.
The emergency measure was authorized in advance of another winter storm expected to hit today.
Tarr said the severity of Thursday’s nor’easter took residents and officials by surprise.
“Now we are moving as fast and effectively as we can to prepare for other tides that might be coming,” he said.
On Thursday, a gusty rainstorm combined with a surging high tide combined to destabilize sand surrounding several houses on Annapolis Way, which is south of the “center” where the Jeanne Geiger building stands.
At least four houses — at 29, 31, 35 and 37 Annapolis Way — sustained significant damage to their decks and stairways; three have been declared off-limits to owners because of concerns about stability. Damaged sections of the structures were removed yesterday as public-safety measures.
But Sam Joslin, building inspector for the town of Newbury, indicated that the structures are not currently in danger of collapsing onto the beach.
Bob Connors, a spokesman for the neighborhood and construction executive, said his house at 39 Annapolis Way is on pilings and still inhabitable.
“But I feel so badly for my neighbors and those who live in this area,” he said.
Yesterday, scores of visitors walked along the beach, expressing awe at how far into the dunes the surf had pervaded and how vulnerable the houses that are near “hot spots” of erosion appeared.
Bill Sargent, an Ipswich author who has written several books about the erosion factors on barrier islands such as Plum Island, said, “The only way this (house) damage will cease is to move the houses back from the beach.”
Some Plum Island residents expressed concern that if oceanfront houses collapse onto the beach, the water and sewer systems of the island could be compromised because they depend on a vacuum system to move water.
Those services are supervised by Newburyport officials, who yesterday said they are staying on top of the situation.
“The city has excellent engineers who are monitoring the system,” Newburyport Mayor Donna Holaday said.
Yesterday’s action plan to provide buffers against future surges was accompanied by a discussion of whether earlier beach-scraping efforts had been helpful on that portion of Plum Island.
Last fall, a core of about eight homeowners received permission from local, state and federal officials to scrape sand from portions of the beach that had an “excess” of matter to sectors in front of houses threatened by erosion.
The action was taken despite the fact that town leaders have heard that scraping can fall short of full effectiveness.
The town cooperated with the state Executive Office of Energy and Environmental Affairs on a 2010 study, the result of which was the “Beach Scraping Workgroup Report.”
That report said, in part, “The findings of all of the studies evaluated by the panel were consistent in areas experiencing high rates of erosion, that scraping exacerbates erosion within the regions scraped, by altering the morphology of the beach profile and creating a loose, more easily erodible fore-dune.”
The report, which is on the town’s website, also said, “The panel consensus, based on available science, was that beach scraping at Plum Island would likely increase erosion.”
Numerous Plum Island residents felt that scraping had helped during recent Superstorm Sandy, because no serious damage was reported.
Tarr said it would be useful to study the effects of scraping. One reason that town officials are earmarking $10,000 to the latest effort is to study and implement effective methods of erosion control.
“I think that scraping helped for Sandy,” Board of Selectmen Chairman Joe Story said. “About its long-term effects, we don’t know.”
Regarding their latest unit of protection, town officials said that some sand envelopes will be constructed to a size of 3-by-3-by-9 feet in size. Others will be longer and higher.
The units and placement are being provided by Netco, a special services and construction company based in Lexington.
Doug Packer, conservation agent for Newbury, said Newburyport previously installed similar sand bags on the beach at the ends of 53rd, 55th and 57th streets, and he said they have proven successful.
“I am optimistic that the (bagging) will be effective,” he said. “We tested them at the center, and they can take a lot of force.”