South Bethany, DE Coastal Erosion Rate
What USGS measures 1.2 miles southwest of South Bethany, DE
The coast 1.2 miles southwest of South Bethany, DE has been retreating at a measured 0.98 feet a year, USGS's own long-term rate for this stretch, built from historical shoreline positions rather than a single survey. At that rate, the shoreline has lost roughly 9.8 feet over the last decade.
What this reading actually covers
This is a roughly 3.5-mile stretch of coast, not one address or parcel - USGS's own transects run every few hundred feet, but that's finer than any one property needs, so this page reports the stretch nearest South Bethany, DE. Centered near 38.50°N, 75.07°W. 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.
25 years at this rate
If 0.98 ft/yr holds for the next 25 years, the coast 1.2 miles southwest of South Bethany, DE would retreat roughly 25 more feet, a projection, not a certainty: erosion rates shift with storms, sediment supply and any armoring built in the meantime.
How solid is this number
Averaging 112 separate transects produced this segment's rate, with 100% individually reading as erosion, rather than relying on any single survey line. Uncertainty on this specific number: 0.23 ft/yr either side. Sorted from fastest erosion to fastest growth across all 1211 measured segments nationally, this one lands at 198. Source: USGS Open-File Report 2010-1119. Rank 327 nationally for erosion belongs to Green Harbor, MA, 338 miles from this stretch, measured at 0.44 ft/yr, 0.4x this stretch's rate. 3.5 miles away, Bethany Beach, DE is the nearest other measured stretch: slight erosion at 0.77 ft/yr.
Not this whole stretch, just South Bethany itself: the Coastal Change Hazards Portal is USGS's own live version of this data.