San Clemente, CA Coastal Erosion Rate
Shoreline change 1.8 miles southwest of San Clemente, CA
0.19 feet a year: that is the measured retreat rate USGS's transects show for the coast 1.8 miles southwest of San Clemente, CA, averaged across the full historical record surveyed here. At that rate, the shoreline has lost roughly 1.9 feet over the last decade.
The grain of this number
Nothing here is parcel-level. USGS's raw transects run every few hundred feet along the shore; this page averages the ones nearest San Clemente, CA into one ~3.5-mile reading rather than picking a single arbitrary line to represent the area. Centered near 33.42°N, 117.63°W. Survey years: 1852-2016, method LRR, from USGS's California 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.
25 years at this rate
If 0.19 ft/yr holds for the next 25 years, the coast 1.8 miles southwest of San Clemente, CA would retreat roughly 5 more feet, a projection, not a certainty: erosion rates shift with storms, sediment supply and any armoring built in the meantime.
What backs this reading up
This reading comes from 3 individual transects averaged together, 100% of which measured erosion rather than growth. The published margin on this reading runs ±0.11 ft/yr. Among the 1211 US coastal segments with a measurable trend, this one ranks 519 for erosion, 1 being the fastest-retreating coast in the dataset. Source: USGS National Shoreline Change data release (ScienceBase, DOI 10.5066/P94J0K7Z), Kratzmann 2024 / Data Report 1187. Rank 418 nationally for erosion belongs to Goleta, CA, 150 miles from this stretch, measured at 0.28 ft/yr, 1.5x this stretch's rate. 1.9 miles away, San Clemente, CA is the nearest other measured stretch: also no significant trend.
One address near San Clemente: the Coastal Change Hazards Portal zooms past this stretch to the underlying map.