Imperial Beach, CA Coastal Erosion Rate
What USGS measures 1 miles southwest of Imperial Beach, CA
Good news, and an honest one: USGS's data can't distinguish this stretch, 1 miles southwest of Imperial Beach, CA, from a flat trend. Whatever small movement it measured here is statistical noise, not a reliable direction, so none is claimed.
What "Imperial Beach" means on this page
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 Imperial Beach, CA, rather than showing one arbitrary line. Segment center: 32.56, -117.13. The survey behind it runs to 1852-2016, in USGS's California 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
This reading comes from 71 individual transects averaged together, 85% of which measured erosion rather than growth. Uncertainty on this specific number: 0.28 ft/yr either side. The unadjusted figure here, -0.25 ft/yr, would place it 449 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 National Shoreline Change data release (ScienceBase, DOI 10.5066/P94J0K7Z), Kratzmann 2024 / Data Report 1187. Atlantic City, NJ sits at national rank 1137 for growth (1.38 ft/yr), one reference point among the 1211 scored segments, 2410 miles from here. 1.4 miles up the coast, Imperial Beach, CA shows the same lack of a significant trend.
One address near Imperial Beach: the Coastal Change Hazards Portal zooms past this stretch to the underlying map.