Bolinas, CA Coastal Erosion Rate
What USGS measures 2.8 miles northwest of Bolinas, CA
Averaged across every transect USGS ran 2.8 miles northwest of Bolinas, CA, the shoreline has been moving inland at 0.18 feet a year, a real measured rate, not a regional estimate applied to this stretch. At that rate, the shoreline has lost roughly 1.8 feet over the last decade.
What this reading actually covers
Bolinas, CA is the nearest named place, 2.8 miles away, to a ~3.5-mile stretch of coast USGS has surveyed - the reading below covers that whole stretch, not a single property in it. Segment center: 37.94, -122.76. 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.
What 0.18 ft/yr means over time
Run 2.8 miles northwest of Bolinas, CA's 0.18 ft/yr rate forward 25 years and it implies about 5 feet of further retreat, assuming nothing changes, which is exactly the assumption a seawall or nourishment project exists to break.
How solid is this number
Averaging 83 separate transects produced this segment's rate, with 92% individually reading as erosion, rather than relying on any single survey line. USGS's confidence interval here is ±0.15 ft/yr. Among the 1211 US coastal segments with a measurable trend, this one ranks 532 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. Virginia Beach, VA sits at national rank 111 for erosion (2.4 ft/yr), one reference point among the 1211 scored segments, 2546 miles from here. 1.9 miles up the coast, Bolinas, CA shows the same lack of a significant trend.
Bolinas, CA on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.