Bethany Beach, DE Coastal Erosion Rate
Is the coast eroding 3.3 miles north of Bethany Beach, DE?
USGS's shoreline-change data puts this stretch, 3.3 miles north of Bethany Beach, DE, at 0.84 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 8.4 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 Bethany Beach, DE, rather than showing one arbitrary line. Segment center: 38.58, -75.07. The survey behind it runs to 2007-2009, in USGS's New England / Mid-Atlantic assessment, using the LRR method. Shoreline surveys aren't repeated every year, so this is the most recent long-term measurement USGS has published for this coast, not a live reading.
What 0.84 ft/yr means over time
Run 3.3 miles north of Bethany Beach, DE's 0.84 ft/yr rate forward 25 years and it implies about 21 feet of further retreat, assuming nothing changes, which is exactly the assumption a seawall or nourishment project exists to break.
Where this fits nationally
40 transects feed this segment's number; 100% of them individually measured retreat. The published margin on this reading runs ±0.52 ft/yr. Among the 1211 US coastal segments with a measurable trend, this one ranks 216 for erosion, 1 being the fastest-retreating coast in the dataset. Source: USGS Open-File Report 2010-1119. Pascagoula, MS sits at national rank 17 for erosion (12.75 ft/yr), one reference point among the 1211 scored segments, 960 miles from here. 1.7 miles up the coast, Long Neck, DE shows 2.08 ft/yr of eroding.
Not this whole stretch, just Bethany Beach itself: the Coastal Change Hazards Portal is USGS's own live version of this data.