Lahaina, HI Coastal Erosion Rate
Is the coast eroding 1.2 miles southwest of Lahaina, HI?
Good news, and an honest one: USGS's data can't distinguish this stretch, 1.2 miles southwest of Lahaina, HI, from a flat trend. Whatever small movement it measured here is statistical noise, not a reliable direction, so none is claimed.
What "Lahaina" means on this page
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 Lahaina, HI, rather than showing one arbitrary line. Segment center: 20.87, -156.68. 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.
How solid is this number
20 transects feed this segment's number; 90% of them individually measured retreat. Uncertainty on this specific number: 0.27 ft/yr either side. The unadjusted figure here, -0.13 ft/yr, would place it 602 of 1211 if ranked directly - but an unreliable rank isn't a useful one, which is exactly why "no significant trend" is the headline instead. Source: USGS Open-File Report 2011-1009. Seal Beach, CA sits at national rank 1053 for growth (0.63 ft/yr), one reference point among the 1211 scored segments, 2513 miles from here. 2 miles up the coast, Lahaina, HI shows the same lack of a significant trend.
One address near Lahaina: the Coastal Change Hazards Portal zooms past this stretch to the underlying map.