Following are two of its projects that include natural and nature-based engineering features - The Fire Island Inlet to Montauk Point, New York, Coastal Storm Risk Management Project, and the Hudson Raritan Estu - ary New York and New Jersey Ecosystem Restoration Project. Fire Island Inlet to Montauk Point, New York, Coastal Storm Risk Management Project This project is taking place along the south shore of Long Island, New York. Long Island extends out east into the Atlantic Ocean from New York City. Along the south shore of the island there are barrier island chains from Coney Island to Shinnecock Inlet. A barrier island is a long narrow island that lies parallel and close to the mainland, protecting the mainland from erosion and storms. The project encompasses an 83-mile subset of the barrier islands of the south shore of Long Island – from Fire Island Inlet to Montauk Point and extends inland two miles. In between Long Island’s main- land and these barrier islands are the Great South Bay, Moriches Bay and Shinnecock Bay. Over the years, the south shore of Long Island has become very populated. Today, there are approximately 150,000 residents within the project area. The region also receives a large influx of seasonal beachgoers and visitors annually. The south shore is also very developed. Within the project area, there are 46,000 buildings that include 42,600 homes and 3,000 businesses, and critical infrastructures including 60 schools, 2 hospitals, and 21 firehouses and police stations. In the past century, especially in the last 20 years, Long Island’s devel- oped coast has experienced storm damages. Elevated tides and waves from these storms caused extensive flooding and sand erosion, leaving communities and shore life vulnerable. In 1992, a Nor’easter breached a barrier island in several locations. Water from the ocean side of the island washed over and into the bay side, splitting the island, creating a breach or gap. The breach quickly turned into a full-blown major inlet that swallowed up 160 homes. Most recently was Hurricane Sandy in 2012. Storm surge from Sandy eroded forty percent of the beach sediment from some areas and cre- ated three breaches in the barrier islands, leaving the area vulnerable to significant damages. This project is a collaboration between numerous agencies and com- munities that will manage the risks and attendant loss of life from tidal flooding, waves, and erosion, in part by restoring the natural coastal processes while minimizing environmental impacts for the barrier is- lands and back bay communities on Long Island’s south shore. The project utilizes conventional, natural, and nature-based features that include the restoration of barrier islands, beaches, and dunes. Restoration of Barrier Islands According to the International Guidelines, barrier islands are a critical element in the multiple lines of defense when it comes to coastal flood - ing. They provide multiple benefits including reducing coastal erosion and flooding from wind-driven waves and extreme water levels, on
the nearby habitats and shorelines. In addition, they provide critical habitat for threatened and endangered species and migratory birds, as well as provide access to recreational opportunities and navigation. As part of this project, the eroded barrier island chains from Fire Island Inlet to Shinnecock Inlet and the shorefront area east of Shinnecock Bay to Montauk Point will be built back up using dredged sand. According to Peter Weppler, Chief, Environmental Analysis Branch, New York District, U.S. Army Corps of Engineers, “Building these barrier islands up will also help to restore the natural cross barrier is- land transport of sand. This sand will naturally flow to areas where it’s needed, augmenting the resiliency, and enhancing the overall barrier island’s natural system coastal processes.” Maintaining barrier islands is so critical that the Army Corps estab- lished a range of breach response plans that will close barrier island breaches immediately after storms for the next 30 years. Restoration of Beaches & Dunes According to the International Guidelines, beaches and dunes are valu- able to flood risk reduction because they dissipate wave energy, can trap sediments, and have the potential to grow with rising sea levels. In addition, they provide habitat for diverse species. Dunes are areas of the beach where sand is elevated several feet to act as a buffer between the waves, wind, storm water levels and the structures landward on the beach. Over the years, much of Long Island’s south shore has eroded, remov- ing the natural beachfront and dunes that provide coastal protection to the communities from storm surge. The beaches and dunes will be restored with sand dredged from several federal channels including Fire Island Inlet and shoals and Moriches and Shinnecock Inlets and shoals and from offshore sand borrow areas. The sand will be placed in a way to mimic natural features and na- tive vegetation will be planted to create nesting and foraging habits for endangered wildlife, including the piping plover, least turn, black skimmers, yellow oystercatchers, and sea beach amaranth. A sand-replenished beach with dunes can prevent elevated ocean waters, caused by storms, from inundating coastal communities. Ac- cording to Anthony Ciorra, project manager, New York District, U.S. Army Corps of Engineers, “Post-Hurricane Sandy analysis showed that beaches that had previously received sand placement and dune construction sustained less damages and saved an estimated $1.3 Bil- lion in avoided damages on New York and New Jersey shorelines.” Aram Terchunian, coastal geologist & president of First Coastal Con- sulting Corporation saw this first-hand on the south shore of Long Island. He said, “Superstorm Sandy is the event that really proved the importance of beaches and dunes as effective natural features. Sandy was a violent storm that broke three inlets through Long Island’s bar- rier beach system. At West Hampton Dunes, it was a nonevent. The beaches and dunes withstood the storm fury with only a small incur-
27
April 2023 csengineermag.com
Made with FlippingBook Annual report