On Staten Island, a massive barrier will rise to protect against climate change
New York City’s latest efforts to fight climate change underscore the reality that the city is facing a very tenuous future
ut on the east coast of Staten Island, one of New York City’s first major responses to the existential threat of climate change may soon break ground. This March, the last bit of bureaucratic red tape was cleared away for the construction of an enormous 5.3-mile long barrier that will stretch from Fort Wadsworth to Oakwood Beach. The United States Army Corps of Engineers (USACE) is now planning to break ground on this $615 million project in 2020, and expects it to be finished in approximately four years.
Officially known as the South Shore of Staten Island Coastal Storm Risk Management Project, the USACE’s barrier is staggering in scope. It will include a 4.3-mile seawall with a public promenade built on top, one mile of levees and floodwalls, and more than 180 acres of newly excavated stormwater detention ponds. The project encompasses an area with over 30,000 residents and 7,300 structures, and will protect some of the coastal neighborhoods that suffered the worst damage during Hurricane Sandy, including Arrochar, South Beach, Ocean Breeze, Graham Beach, Midland Beach, New Dorp Beach, and Oakwood Beach.
“The project is designed to reduce risk of flooding and damage from severe storms such as nor’easters, hurricanes, and other weather events that involve tidal surges. Specifically, the project is designed to function under a storm producing water levels of a 300-year flood event (a storm with a 0.3 percent chance of occurring in any given year),” Frank Verga, the USACE project manager, says via email. “It provides a complete solution incorporating project features to address flooding not only due to coastal storm surge, but also due to precipitation.”
When Hurricane Sandy hit New York City in 2012, the neighborhoods closest to the seawall site were badly damaged, as the ocean surged through the streets, crushing homes and killing 24 Staten Island residents. For the communities that remain intact along this section of the coast—including Arrochar, Midland Beach, and New Dorp Beach—the USACE barrier system cannot be built soon enough. Many of the flood-damaged houses in these neighborhoods have remained empty since the storm, waiting to be repaired, demolished, or elevated up above the floodplain, while the temporary coastal barriers that were put in place have already begun to collapse and erode into the sea. If another major storm were to come today, some of these same neighborhoods could be flooded again.
Unfortunately, the Staten Island seawall will not arrive in time to save all of the areas situated in its shadow. Three of the communities immediately adjacent to the barrier—Ocean Breeze, Graham Beach, and Oakwood Beach—have been almost completely demolished as part of a “managed retreat” away from the waterfront. This buyout program was facilitated by New York state’s Office of Storm Recovery, and has helped to relocatehundreds of Staten Island homeowners away from the coast. No new structures can be built on these properties in the future, and a large portion of the land that will be protected by the new seawall is already permanently uninhabited, populated only by deer, geese, possums, and turkeys.
Despite the USACE’s extensive research, exactly how much protection the barrier will be able to provide in the future remains uncertain, as sea levels continue to rise at an increasing rate. The seawall is intended to protect the coast from a storm surge of “about two feet higher than the peak water levels during Hurricane Sandy,” according to a 2016 feasibility report, and is designed to account for “an intermediate rate of sea level rise of 1.1 feet” over the next 50 years. This is a remarkably lower intermediate rate of sea level rise that what is anticipated by the New York state Department of Environmental Conservation, which expects between 1.5 feet and 6.25 feet of sea level rise to occur in the next 81 years.
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