Manchester, CA Coastal Erosion Rate
Is the coast eroding 2.4 miles southwest of Manchester, CA?
2.4 miles southwest of Manchester, 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.
What this reading actually covers
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 Manchester, CA. Centered near 38.96°N, 123.73°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.
How solid is this number
16 transects feed this segment's number; 100% of them individually measured retreat. USGS's confidence interval here is ±0.34 ft/yr. Taken at face value, this segment's raw -0.23 ft/yr reading would land it 473 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. El Segundo, CA sits at national rank 1114 for growth (1.04 ft/yr), one reference point among the 1211 scored segments, 456 miles from here. 0.9 miles up the coast, Manchester, CA shows the same lack of a significant trend.
Not this whole stretch, just Manchester itself: the Coastal Change Hazards Portal is USGS's own live version of this data.