Biddeford, ME Coastal Erosion Rate
Shoreline change 1.6 miles east of Biddeford, ME
Good news, and an honest one: USGS's data can't distinguish this stretch, 1.6 miles east of Biddeford, ME, from a flat trend. Whatever small movement it measured here is statistical noise, not a reliable direction, so none is claimed.
The grain of this number
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 Biddeford, ME, rather than showing one arbitrary line. Segment center: 43.45, -70.36. 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.
How solid is this number
Averaging 54 separate transects produced this segment's rate, with 37% individually reading as erosion, rather than relying on any single survey line. USGS's confidence interval here is ±0.23 ft/yr. The unadjusted figure here, 0.06 ft/yr, would place it 826 of 1211 if ranked directly - but an unreliable rank isn't a useful one, which is exactly why "no significant trend" is the headline instead. Source: USGS Open-File Report 2010-1119. For scale: Ocean Park, WA, 2581 miles away, ranks 1113 of 1211 nationally for growth, 1.04 ft/yr. 1.2 miles away, Biddeford, ME is the nearest other measured stretch: also no significant trend.
Not this whole stretch, just Biddeford itself: the Coastal Change Hazards Portal is USGS's own live version of this data.