One year after Hurricane Sandy dealt a knock-out punch to the mid-Atlantic and cast a glancing blow to the Vineyard, the question as to how New England will fare in the next great storm has been the subject of much discussion up and down the coast. The Vineyard has been lucky, said Dr. Jeffrey Donnelly, an associate scientist at the Woods Hole Oceanographic Institution. But eventually the Island’s number will come up. Go back, for example, to the Great Colonial Hurricane of 1635. When that storm hit New England, the eye came ashore somewhere between Boston and Plymouth, leaving in its wake a 20-foot storm surge in Buzzards Bay. “It’s entirely plausible that an event like that would return,” Dr. Donnelly said in a telephone interview this week. Using the National Oceanic and Atmospheric Administration hurricane inundation computer models, Mr. Donnelly took the 1635 hurricane storm and moved the track of it to make landfall on Martha’s Vineyard and Woods Hole to come up with a worst-case scenario for the Island.
“It’s fairly significant,” he said.
He found that the south shore would be hardest hit, with a storm surge of up to 10 feet. The north shore would not fare well either, he said, even with sheltering from Vineyard Sound, and would see a storm surge of up to eight feet.
“The impacts of a surge flooding would be considerable, but the other thing to consider is that it’s not just the surge and the coastal impacts,” Mr. Donnelly said. “Sandy was a minimal hurricane and didn’t result in much in the way of interior damage . . . but if you get a hurricane like 1635 or 1938, a strong category three storm is wiping out homes and ripping roofs off and downing entire forests. If something like that were to make a very close path to Martha’s Vineyard, it wouldn’t just be coastal erosion and inundation from the surge — the entire Island would be decimated in terms of damage to structure and damage to forests. It’s a pretty catastrophic worst-case scenario and it actually happened in the last few hundred years.”
Mr. Donnelly described benchmark storms through history, including the hurricane of 1938, which directly hit southern New England with sustained winds of 100 miles per hour. That storm completely destroyed Menemsha. In 1869 a category three hurricane made landfall in Providence, R.I., followed by another hurricane that bisected Cape Cod a few weeks later. There was a significant storm in 1944. And 1954 was a big year for the region, Mr. Donnelly said. That year Hurricane Carol hit in late August, followed by Edna several weeks later. Hurricane Donna landed in 1960, and then storms quieted, he said. There was Gloria in the 1980s, and Hurricane Bob in 1991. The Island felt the remnants of Hurricane Earl in 2010 and tropical storm Irene in 2011. Sandy’s track last year took a “very unusual turn” into New Jersey, Mr. Donnelly said. Modeling Sandy on a routine projected track, he said its impact here would have been something less than Hurricane Bob.
“It would have been not quite as bad as Bob but still significant coastal flooding,” the scientist said. “What made Sandy such a big event is that it happened to hit a really populated area and there was lots of focusing on that surge; it was a big, slow-moving storm that was able to pile up a lot of water and hit at high tide.”
Computer models project increased storm activity along the Eastern Seaboard over the next several decades, Mr. Donnelly said.
“It’s something we should be thinking about and trying to prepare for,” he said. “Time will catch up with us eventually. We might get lucky for a few decades but eventually your number is going to be up.”
NOAA predicted an active 2013 hurricane season, but in fact this year has been quiet so far. Hurricane season runs from June 1 through Nov. 30, with peak times in New England around September and October.
“I think NOAA went out on a limb. The issue is there are so many different factors that go into tropical storm and cyclone activity, it’s hard to predict year to year,” Mr. Donnelly said. “Overall the conditions are getting more favorable for bigger storms and that’s the issue.”
Long term, he said sea level rise also is a factor.
“The sea level is rising a few millimeters per year and extend that over decades — since the 1938 hurricane sea level rise is up one and a half feet,” he said. Since the 1635 hurricane, sea level has risen three feet in this area.
“All of that is projected to accelerate,” Mr. Donnelly said.
Washed out roads and bridges are a growing concern, especially on the Cape and the Islands.
“We’re still in trouble because our infrastructure is getting closer to the ocean,” he said.
There’s good news too, though, beginning with the fact that the topography of the Vineyard is not too low lying.
“In that sense you’re not in any immediate danger of drowning,” Mr. Donnelly said.
And he took special note of the fact that the Vineyard shorelines are largely undeveloped compared with other places along the Eastern Seaboard.
“You’ve been fairly smart about how you’ve developed immediately on the coast — it’s a very different scenario than the rest of southern New England,” he said. “Your infrastructure is not as vulnerable.” As for the vast network of coastal ponds on the Island, he said: “The coastal ponds have been there for 9,000 years and they will be there for thousands more.”
At a local planning level, the Martha’s Vineyard Commission is looking at all the scenarios. Hurricane storm surge maps provided by the U.S. Army Corps of Engineers and NOAA are being overlaid with information from the commission including buildout, infrastructure, roads and emergency services.
“Storm surge is what kills people and does the most of the damage; it comes up very quickly and just beats up everything in its path,” said JoAnn Taylor, the commission’s coastal planner.
The commission assesses vulnerability and impact for both northeasters and hurricanes using different tools: number of people, number of residences, the value of buildings, build-out and geographical vulnerability, she said. The so-called SLOSH (Sea, Lake and Overland Surges from Hurricanes) maps are on the commission website.
“For hurricane vulnerability it’s totally dependent on the direction of where the hurricane comes from,” Ms. Taylor said.
A three-day northeaster can also wreak damage equal to a hurricane, she said.
“It can be quite impressive by the time it’s done in what kind of damage it’s done to the beaches and docks and boats,” Ms. Taylor said. “It’s pounding and pounding and pounding for three days.”
The commission is working with Island towns to develop storm mitigation plans. Among other things, the plans allow towns to be eligible for funding from the Federal Emergency Management Agency (FEMA).
“What can we do to reduce the threat to life and property,” Ms. Taylor said. Edgartown, for example, was recently awarded $374,000 in FEMA funding that will go toward retrofitting a sewer substation on Dock street.
A year after Sandy, the Vineyard is still taking stock. Compared with New York and New Jersey, the Island was largely spared. There was severe coastal erosion along the south shore beaches, especially at Lucy Vincent and Squibnocket in Chilmark. A handful of homes from Chilmark to Chappaquiddick were moved or demolished after the storm accelerated erosion along already-eroding coastlines. Lobsterville Road in Aquinnah was damaged. The Steamship Authority wharf in Oak Bluffs sustained serious damage and has undergone $2 million worth of repairs in the past year. East Chop Drive in Oak Bluffs, already undermined by previous storms, was left severely compromised after Sandy. The road is restricted to one-way traffic for the winter.
And lessons are still being learned. Wayne Lamson, general manager of the Steamship Authority, said he monitored the storm closely like many others. But as the storm approached and the U.S. Coast Guard closed all ports, the SSA was still in the midst of transporting utility trucks to the Island in advance of the storm. Mr. Lamson explained the circumstances to the Coast Guard and eventually convinced them to allow the ferries to continue to run.
The SSA also decided to tie up in Woods Hole and on the Vineyard rather than take vessels into Fairhaven behind the hurricane barrier.
“As a result we were able to come back quicker,” he said.