San Simeon, CA Coastal Erosion Rate
What USGS measures 7.6 miles northwest of San Simeon, CA
7.6 miles northwest of San Simeon, CA: USGS's transects didn't pick up a trend here that beats the survey's own uncertainty. That's the majority case nationally, and for this stretch specifically it means the coast is holding, not that the data failed to find anything.
The grain of this number
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 San Simeon, CA. Centered near 35.66°N, 121.26°W. 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
20 transects feed this segment's number; 90% of them individually measured retreat. USGS's confidence interval here is ±0.31 ft/yr. Taken at face value, this segment's raw -0.17 ft/yr reading would land it 546 of 1211 nationally - a number worth ignoring, since it's statistical noise rather than a real trend. Source: USGS National Shoreline Change data release (ScienceBase, DOI 10.5066/P94J0K7Z), Kratzmann 2024 / Data Report 1187. Port St. Joe, FL sits at national rank 1067 for growth (0.73 ft/yr), one reference point among the 1211 scored segments, 2122 miles from here. San Simeon, CA, 1.3 miles off, is the adjacent measured stretch, itself no significant trend.
One address near San Simeon: the Coastal Change Hazards Portal zooms past this stretch to the underlying map.