Bolinas, CA Coastal Erosion Rate
What USGS measures 1.2 miles southeast of Bolinas, CA
0.39 feet a year: that is the measured retreat rate USGS's transects show for the coast 1.2 miles southeast of Bolinas, CA, averaged across the full historical record surveyed here. At that rate, the shoreline has lost roughly 3.9 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 Bolinas, CA into one ~3.5-mile reading rather than picking a single arbitrary line to represent the area. Centered near 37.90°N, 122.70°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 0.39 ft/yr holds for the next 25 years, the coast 1.2 miles southeast of Bolinas, CA would retreat roughly 10 more feet, a projection, not a certainty: erosion rates shift with storms, sediment supply and any armoring built in the meantime.
Where this fits nationally
Averaging 76 separate transects produced this segment's rate, with 92% individually reading as erosion, rather than relying on any single survey line. The published margin on this reading runs ±0.31 ft/yr. Among the 1211 US coastal segments with a measurable trend, this one ranks 359 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. Dulac, LA sits at national rank 12 for erosion (14.91 ft/yr), one reference point among the 1211 scored segments, 1926 miles from here. 2 miles away, Bolinas, CA is the nearest other measured stretch: also no significant trend.
Not this whole stretch, just Bolinas itself: the Coastal Change Hazards Portal is USGS's own live version of this data.