Rancho Palos Verdes, CA Coastal Erosion Rate
What USGS measures 2.4 miles southeast of Rancho Palos Verdes, CA
USGS's shoreline-change data puts this stretch, 2.4 miles southeast of Rancho Palos Verdes, CA, at 0.15 feet of erosion a year on average, a long-term rate for this specific ~3.5-mile section, not one storm's damage. At that rate, the shoreline has lost roughly 1.5 feet over the last decade.
The grain of this number
USGS surveys the coast in transects spaced a few hundred feet apart; this page groups the nearest ones into a single ~3.5-mile reading for the stretch closest to Rancho Palos Verdes, CA, rather than showing one arbitrary line. Segment center: 33.72, -118.33. 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.
What 0.15 ft/yr means over time
Run 2.4 miles southeast of Rancho Palos Verdes, CA's 0.15 ft/yr rate forward 25 years and it implies about 4 feet of further retreat, assuming nothing changes, which is exactly the assumption a seawall or nourishment project exists to break.
What backs this reading up
Averaging 32 separate transects produced this segment's rate, with 100% individually reading as erosion, rather than relying on any single survey line. USGS's confidence interval here is ±0.08 ft/yr. Sorted from fastest erosion to fastest growth across all 1211 measured segments nationally, this one lands at 572. Source: USGS National Shoreline Change data release (ScienceBase, DOI 10.5066/P94J0K7Z), Kratzmann 2024 / Data Report 1187. Rank 538 nationally for erosion belongs to Scituate, MA, 2624 miles from this stretch, measured at 0.17 ft/yr, 1.1x this stretch's rate. Rancho Palos Verdes, CA, 1.2 miles off, is the adjacent measured stretch, itself no significant trend.
Rancho Palos Verdes, CA on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.