Olowalu, HI Coastal Erosion Rate
What USGS measures 3.9 miles southeast of Olowalu, HI
The coast 3.9 miles southeast of Olowalu, HI 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 this reading actually covers
Nothing here is parcel-level. USGS's raw transects run every few hundred feet along the shore; this page averages the ones nearest Olowalu, HI into one ~3.5-mile reading rather than picking a single arbitrary line to represent the area. Centered near 20.79°N, 156.57°W. Survey years: 2007-2010, method WLR, from USGS's Hawaii 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 backs this reading up
45 transects feed this segment's number; 82% of them individually measured retreat. Uncertainty on this specific number: 0.31 ft/yr either side. Taken at face value, this segment's raw -0.1 ft/yr reading would land it 647 of 1211 nationally - a number worth ignoring, since it's statistical noise rather than a real trend. Source: USGS Open-File Report 2011-1009. Camp Pendleton South, CA sits at national rank 1091 for growth (0.9 ft/yr), one reference point among the 1211 scored segments, 2540 miles from here. 2 miles up the coast, Olowalu, HI shows the same lack of a significant trend.
Olowalu, HI on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.