To adapt or retreat: Mitigating coastal erosion on M.V.

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It wasn’t a hurricane or a nor’easter that caused part of a 30-ton seawall on Martha’s Vineyard to collapse in 2008. Instead, it was a minor rain event. On a gloomy day in February, an overcast sky released its showers over the downtown of Oak Bluffs. As the rain continued to fall, it trickled off the pavement and down onto the sandy bluffs. Before long, the silt beneath the Pay Beach seawall had become saturated. The cement structure trembled against the cascade of rain and sand. In an instant, the wall gave way to the runoff, debris crumbling onto the sloping bluff of Seaview Avenue. Town conservation agent Liz Durkee knew of the concrete’s unstable condition, but had deferred action. She knew that a seawall repair was, at best, a temporary solution to a much more complex issue. As the only barrier protecting a low-lying downtown from storm surges and flooding, the seawall’s collapse was a wake-up call: The climate crisis was here, at the Oak Bluffs shoreline.

For decades, the Vineyard has been the destination for celebrities, Pulitzer prizewinners, and presidents. Seclusive seaside manors tucked away down winding dirt roads have become the preferred hideaways for the rich and famous. Oak Bluffs, formerly known as Cottage City, is one of six towns on Martha’s Vineyard. While one of the smallest towns, its wealth of town beaches and cultural heritage makes Oak Bluffs one of the most populated, diverse towns on the Island. 

In the coming decades, climate symptoms experienced by the Island’s population will only get worse. Summer crowds can swell up to 115,000, while the year-round population hovers around 17,000. Despite attempts by conservation commissions to armor the coast, it is inevitable that the 125-mile shoreline will continue to recede. Major coastal roadways, including Lagoon Pond Road and Beach Road, have already experienced a significant increase in flooding over the past couple of years. In the event of a Category 4 hurricane, all access roads to the Island’s only hospital will be underwater. Coastal and estuarine ecosystems will be adversely affected. With shrinking shorelines, endangered species like piping plovers, who prefer to nest on the high shore, close to the dunes, will face displacement. Costly resources will continue to be expended to protect the Island’s iconic lighthouses, many of which date to the 19th century. The nation’s oldest carousel, the Flying Horses, sits only 135 feet away from the encroaching Nantucket Sound. 

The Wampanoag Tribe of Gay Head (Aquinnah), pioneers of the whaling and fishing industry, have nearly 500 acres of ancestral lands at stake. On Cranberry Day, seaside cranberry bogs are harvested in keeping with Wampanoag tradition. However, if warming temperatures and invasive species don’t ruin the bogs, sea level rise will. The threatened cranberry bogs remind us that our ecosystems will be facing symptoms far more complex than just rising sea levels. All of these changes would signal huge losses for the people who have such a deep affinity for the land. Whether they know it or not, celebrities, vacationers, and the fiercely loyal local residents are relying on conservationists like Durkee to preserve their beloved Island.

The harm, most likely, will be a significant weather event, according to coastal geologist Greg Berman. Berman stresses that the effects of 10, 20 or even 50 years of gradual erosion can be achieved in a single storm, depending on intensity. In 2012, the Vineyard fortuitously escaped the wrath of Hurricane Sandy, sustaining only minor damage. However, when the big storm does hit, Berman cautions, it could be calamitous. For a town like Oak Bluffs, where most infrastructure has been constructed on or near the water, flooding will be inevitable when a hurricane makes contact with the shoreline. Up against the insurmountable forces of Mother Nature, Islanders will have to make a choice: Do they adapt or retreat?

In a grim tone, Durkee said, “The only way to really protect the Island would be to build a stone wall around the whole thing.” She pauses to laugh at the absurdity of her idea, but before long, her rational side interjects, “But then, we’d lose all the beaches, and that’s what people come here for.”

Durkee’s fixation with climate began with newspaper clippings: lots and lots of clippings. Fifteen years ago, before national newspapers dared to put the climate crisis in bold type, odd local headlines had caught the attention of Durkee, who was in the early days of her career as a conservation agent. To an untrained eye, the headlines were nothing but alarmist: How could low levels of ozone possibly be related to plants blooming too soon? To Durkee, these seemingly inconsequential stories were a marker of a larger issue at hand: an ecosystem dangerously out of sync. Determined to find a connection between warming temperature and systems in disarray, Durkee delved into research. Snipping away at these articles, she became convinced that she was right — something more complex was going on. 

While it may be Durkee’s professional responsibility to be educated on potential impacts of climate change, her clippings live at home rather than the office, because her passion for environmentalism reaches far beyond a salary. Having worked for the town since 1995, Durkee embarked on the conservation crusade long ago. Whether it’s researching ways to mitigate erosion, typing up grant proposals, or analyzing wildfire vulnerability, she is always looking for new opportunities to safeguard the Island.

When making the decision to approve a rebuilding project, the town will have to weigh the cost of lost property taxes against the recreational value of surrounding beaches. Berman said, “One of the issues with inlanders versus primary shoreline homeowners is that if you live inland, you might drive down and enjoy the beach, but if you live right on the water, you want to protect your house over protecting the beach in front of it. If we lose all the beaches and dunes, we’re not going to get the tourists anymore, which is another huge economic drive for the town.” 

As the water’s edge continues to shrink in response to rising sea levels and erosion, oceanfront property holders — often seasonal residents — will sustain the immediate damage, but ultimately, the losses will be experienced Island-wide. Over the years, the price points of inland homes have been inflated in response to the fleets of wealthy vacationers looking to snatch up second homes. Former town administrator Michael Dutton said, “The change has been driven by the very wealthy people coming and buying up properties, which essentially drives up the value of all the property on the Vineyard disproportionately. The property out there is far more valuable than a comparable piece of property over in Falmouth or Plymouth.” 

If the Vineyard’s most expensive properties lose their value, it will consequently affect the value of the inland homes. “All the signs say that the coastal real estate market is going to crash at some point,” Durkee said. East Chop, a scenic headland sprawled with summer homes, stands out as a victim of severe storm damage and political impasse. In 2018, the Oak Bluffs selectmen voted to permanently close East Chop Drive — a roadway meandering along the Nantucket and Vineyard sounds — to vehicular traffic. To reopen, the bluffs would require stabilization repairs estimated to cost between $17 million and $20 million. In attempting to secure funding to fix an area mainly inhabited by summer residents, Durkee has run into public scrutiny along the way. “Some people aren’t happy with that, because they think we’re trying to protect the second homeowners who live on top of the bluff, but really it’s a scenic and culturally significant road for the public,” she said.

As storms continue to grow in intensity, wreaking havoc on exposed dunes, bluffs, and homes, the cost of mitigation and restoration efforts will only steepen. Although the Vineyard has collectively accepted its identity as a summer resort community, that could change down the road. Durkee said, “Why would people want to come to a storm-ravaged place where the roads are washed out and homes are damaged and businesses are flooded, when they can just go to the mountains?”

Upon investigating the seawall’s failure in 2008, Durkee discovered that many seawalls bordering the town’s beaches had been silently deteriorating. North Bluff, a beach adjacent to the channel of the Oak Bluffs Harbor, was discovered to be in dire condition. Over the years, the beach that Durkee had taken swimming lessons at as a child had vanished to the point of near nonexistence. The reason this particular beach had become so sediment-starved had much to do with coastal armoring — manmade attempts to fortify shorelines from the natural process of erosion. In the early 20th century, when the town decided to armor East Chop, the consequences of the intervention were little-known. However, once the 5,500 feet of East Chop shoreline was armored with stone revetment and a timber bulkhead, the deed was irreversible; North Bluff, from then on, would be sediment-starved.

“Erosion is not a dirty word, it’s a natural function. The coast erodes constantly; the problem is that we’ve built in the way,” Durkee said. The unique shapes and landforms that comprise the Cape and Islands were, after all, created by the natural processes of erosion. “It’s those dunes and beaches that have made this a relatively desirable place to live,” said Berman. When a revetment or seawall is built, it prevents the coastal bank — composed of glacial till — from shedding new material to supplement the beaches and dunes. Structures like seawalls, meant to defend against flooding and storm surge, often do the opposite, by accelerating the erosion of sand that has already been deposited on the beach. When a wave hits a seawall, energy is deflected as the wave switches back, which causes the wave to wash large volumes of sand off the beach. Durkee said, “When you put up a seawall, you’re pretty much saying goodbye to your beach, unless you continue to renourish it. People didn’t know that then.” The construction of coastal defense mechanisms, including jetties, groin fields, seawalls, and stone revetments, is now restricted under the Wetlands Protection Act. 

Durkee is not a proponent of coastal armoring, but in cases where manmade structures like groins, seawalls, jetties, or stone revetments have already disrupted the natural course of sediment transport, failing to rebuild a destabilized structure has its own risks. In the case of the North Bluff restoration, beach nourishment followed the construction of an upgraded steel retaining wall. A healthy stretch of beach is the first defense against storm erosion. The second defense is the seawalls, built on top of the bluffs, protecting roadways, homes, and businesses from flooding and storm surge. Berman explains that by simply putting sand down, storm damage can be greatly reduced. He said, “When a wave comes toward the shoreline, it’s supposed to feel the bottom; surfers are very in tune with that, when a wave starts to curl over. When you finally get the break, it’s going to expend a lot of that energy. If you can cause the wave to break further offshore, instead of on the coastal bank, it’s going to greatly reduce the erosion.”

After 13 years of intermittent construction, the multiphase beach restoration of North Bluff was finally completed in April. Having required periodic nourishments for as long as East Chop has been armored, the North Bluff beach’s vast expanse will inevitably dwindle in time. The project, totaling $8 million, may have been pricy, but Durkee saw no other alternative to ensure the short-term well-being of her town. “Beach nourishment projects, they call those ‘projects that are designed to fail,’ because you put the sand there knowing it’s going to disappear, knowing that you’re going to have to keep nourishing,” Durkee said. “But this sand is one piece of the whole bigger picture.” 

Rob Hammett, an Oak Bluffs resident and close friend of Durkee, drove by to see the makeover. The newly restored beach may lack the colorful umbrellas and lifeguard stands of Hammett’s day, but boasts amenities of a boardwalk and fishing pier (completed in 2016). Not as noticeable, but just as important, the steel retaining wall and restructured timber groins serve to lengthen the lifespan of the newly deposited 16,000 cubic yards of sand. With sheer gratitude in his voice, Hammett said in a phone call about Durkee’s work, “I’m sitting here looking at the guys smoothing the sand on the beach right now, and the waves coming in, and I just think that this is such a wonderful thing that she has done. Not so that she has another place to go to the beach, but so that we all do.” From a recreational standpoint, Berman points out, the more space for beach towels, the more potential dollars for the town. 

While Durkee hopes to see residents and tourists enjoying the restored beach this summer, she stresses that the project only intends to provide short-term relief: “I do think we need to start thinking about attracting people for reasons other than just the beaches, because soon enough, there aren’t going to be any. Beaches on the Island are kind of in the autumn of their lives.”

Berman warns that while Massachusetts has made climate resiliency a priority, the state still downplays climate change estimates, including localized sea levels. He thinks that the estimate of three feet of sea level rise in the next 100 years will happen in closer to 50 years. 

To imagine what the Vineyard might look like in the next 50 years, all one has to do is look out over Beach Road on a relatively high-tide day and add three feet of elevation.

“As we start getting pummeled by worse nor’easters, and when we get the big hurricane, it is going to be catastrophic,” Durkee said, “It will devastate the Island, and we don’t have a backup plan for that.”

 

Alexis Condon is a 2019 graduate of MVRHS, and a journalism student at Vanderbilt University. She wrote this piece for her Investigative Climate Change Journalism course.