Manchester, CA Coastal Erosion Rate
What USGS measures 1.6 miles west of Manchester, CA
The coast 1.6 miles west of Manchester, CA shows no statistically significant trend either way. USGS's transects measured a rate here, but it's smaller than the survey's own margin of error for this stretch, so calling it "eroding" or "growing" would overstate what the data actually shows.
What "Manchester" means on this page
Nothing here is parcel-level. USGS's raw transects run every few hundred feet along the shore; this page averages the ones nearest Manchester, CA into one ~3.5-mile reading rather than picking a single arbitrary line to represent the area. Centered near 38.97°N, 123.72°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.
What backs this reading up
This reading comes from 41 individual transects averaged together, 85% of which measured erosion rather than growth. The published margin on this reading runs ±0.27 ft/yr. Taken at face value, this segment's raw -0.16 ft/yr reading would land it 552 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. For scale: Bayshore, OR, 379 miles away, ranks 1126 of 1211 nationally for growth, 1.23 ft/yr. 0.9 miles away, Manchester, CA is the nearest other measured stretch: also no significant trend.
Not this whole stretch, just Manchester itself: the Coastal Change Hazards Portal is USGS's own live version of this data.