Lewes, DE Coastal Erosion Rate
What USGS measures 2.4 miles east of Lewes, DE
Averaged across every transect USGS ran 2.4 miles east of Lewes, DE, the shoreline has been moving inland at 1.73 feet a year, a real measured rate, not a regional estimate applied to this stretch. At that rate, the shoreline has lost roughly 17.3 feet over the last decade.
What this reading actually covers
Lewes, DE is the nearest named place, 2.4 miles away, to a ~3.5-mile stretch of coast USGS has surveyed - the reading below covers that whole stretch, not a single property in it. Segment center: 38.79, -75.10. Survey years: 2007-2009, method LRR, from USGS's New England / Mid-Atlantic shoreline-change assessment. That's how current the data is here, real, but not a live feed, since a shoreline survey is a major undertaking, not an annual check-in.
What 1.73 ft/yr means over time
Run 2.4 miles east of Lewes, DE's 1.73 ft/yr rate forward 25 years and it implies about 43 feet of further retreat, assuming nothing changes, which is exactly the assumption a seawall or nourishment project exists to break.
Where this fits nationally
This reading comes from 65 individual transects averaged together, 75% of which measured erosion rather than growth. The published margin on this reading runs ±0.74 ft/yr. Among the 1211 US coastal segments with a measurable trend, this one ranks 146 for erosion, 1 being the fastest-retreating coast in the dataset. Source: USGS Open-File Report 2010-1119. Seaside Park, NJ sits at national rank 248 for erosion (0.66 ft/yr), one reference point among the 1211 scored segments, 94 miles from here. 2.7 miles away, Henlopen Acres, DE is the nearest other measured stretch: moderate erosion at 2.23 ft/yr.
Lewes, DE on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.