Bolinas, CA Coastal Erosion Rate
Shoreline change 1.2 miles west of Bolinas, CA
1.2 miles west of Bolinas, 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 Bolinas, CA. Centered near 37.92°N, 122.73°W. USGS's California assessment last surveyed this stretch through 1852-2016, 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.
How solid is this number
45 transects feed this segment's number; 96% of them individually measured retreat. Uncertainty on this specific number: 0.27 ft/yr either side. Taken at face value, this segment's raw -0.12 ft/yr reading would land it 620 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. Huntington Beach, CA sits at national rank 993 for growth (0.39 ft/yr), one reference point among the 1211 scored segments, 392 miles from here. 1.9 miles away, Bolinas, CA is the nearest other measured stretch: slight erosion at 0.18 ft/yr.
Bolinas, CA on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.