The COAST Institute at the School of Marine and Atmospheric Sciences at Stony Brook University hosted a Workshop on Resilience and Sustainability of Long Island’s North Shore on Friday October 12, 2018 in Endeavour Hall Room 120.
8:30 Registration/ breakfast
9:00 Introductions: Assemblyman Steve Englebright , Legislator Kara Hahn, Legislator Sarah Anker, Councilwoman Valerie Cartright, and Councilwoman Jane Bonner.
The south shore of Long Island Sound is home to some 380,000 souls, outside of New York City, along 50% of the Sound’s shoreline. In the past decade, these 600 miles of shoreline began showing signs of accelerated erosion threatening the natural protection not only of coastal communities, but also beach, bay and marsh habitats. According to the New York State Department of Environmental Conservation, erosion levels on the south shore of Long Island Sound reach critical levels. Examples of recent problems, like those at Nissequogue, and current situations along the north shore will be discussed.
The north shore is characterized by curvilinear coastal compartments. The curving shoreline is divided into (leaking) compartments from headland to headland or headland to inlet. Sand is added by bluff erosion and redistributed by the longshore transport of wave-driven sand. Bluff erosion occurs locally and episodically during extreme weather supplying the littoral zone with sand.
Wind-driven waves are determined by wind speed, duration and fetch. Because the Sound is open to the sea, storm surges can be large and superimposed on an already large tide resonating in the basin. Computer modeling can forecast changing conditions.
Runoff erosion and undercutting and collapse are determined by the geotechnical characteristics of the bluff. High water levels temporarily drown the beach and allow waves to attack the base of the bluff. The bluff face is undercut and collapses, vegetation is removed and rain runoff carries bluff sand to the beach. The process controlling undercutting and collapse depend on the geotechnical properties of the bluff.
A variety of techniques have been used to control erosion along the north shore. Hard structures include bulkheads, rip-rap, revetments, gabbions, geotextiles. Soft solutions like revegetation is also used including alternative “green” methods, like green gabbions, fiber logs, marsh sills, oyster reets and living breakwaters.
12:15 Discussion and Lunch
12:30 DISCUSSION: “Getting things done”, R.L. Swanson, SoMAS.
Permits for projects to combat bluff erosion are granted on a case-by-case basis. This is a regional issue that needs to be consistent with the State’s broader vision for the coast and any Town Coastal Revitalization Plans. What can be done in the way of resiliency to preserve the character of Long Island Sound’s south shore yet also protect individual properties on the Sound?
1:30 Visit to Wave Flume and a demonstration of bluff erosion.
Dr. Farhadzadeh’s research-grade wave/current flume is capable of generating combined random waves and reversible currents to simulate coastal erosion. The wave/current flume is 80 ft. long, 5 ft. wide and 5 ft. high, equipped with a piston-type wave maker, current-recirculation system and an advanced data acquisition system.