Sagaponack, NY Coastal Erosion Rate
Shoreline change 2.4 miles southwest of Sagaponack, NY
USGS's shoreline-change data puts this stretch, 2.4 miles southwest of Sagaponack, NY, at 0.37 feet of erosion a year on average, a long-term rate for this specific ~3.5-mile section, not one storm's damage. At that rate, the shoreline has lost roughly 3.7 feet over the last decade.
What this reading actually covers
USGS surveys the coast in transects spaced a few hundred feet apart; this page groups the nearest ones into a single ~3.5-mile reading for the stretch closest to Sagaponack, NY, rather than showing one arbitrary line. Segment center: 40.91, -72.30. USGS's New England / Mid-Atlantic assessment last surveyed this stretch through 2007-2009, computing the rate with its LRR method. Other US regions were surveyed in different years, sometimes decades apart, so this page states its own rather than implying one national vintage.
What 0.37 ft/yr means over time
Run 2.4 miles southwest of Sagaponack, NY's 0.37 ft/yr rate forward 25 years and it implies about 9 feet of further retreat, assuming nothing changes, which is exactly the assumption a seawall or nourishment project exists to break.
Where this fits nationally
93 transects feed this segment's number; 100% of them individually measured retreat. USGS's confidence interval here is ±0.28 ft/yr. This segment ranks 364 of 1211 measured US coastal segments, ordered from fastest erosion to fastest growth. Source: USGS Open-File Report 2010-1119. For scale: Plymouth, MA, 112 miles away, ranks 421 of 1211 nationally for erosion, 0.27 ft/yr, 0.7x this stretch's rate. Sagaponack, NY, 2.2 miles off, is the adjacent measured stretch, itself no significant trend.
Sagaponack, NY on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.