Makaha, HI Coastal Erosion Rate
Is the coast eroding 2.2 miles north of Makaha, HI?
The coast 2.2 miles north of Makaha, 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.
The grain of this number
Nothing here is parcel-level. USGS's raw transects run every few hundred feet along the shore; this page averages the ones nearest Makaha, HI into one ~3.5-mile reading rather than picking a single arbitrary line to represent the area. Centered near 21.50°N, 158.23°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.
How solid is this number
Averaging 70 separate transects produced this segment's rate, with 83% individually reading as erosion, rather than relying on any single survey line. The published margin on this reading runs ±0.38 ft/yr. Taken at face value, this segment's raw -0.25 ft/yr reading would land it 441 of 1211 nationally - a number worth ignoring, since it's statistical noise rather than a real trend. Source: USGS Open-File Report 2011-1009. Rank 1150 nationally for growth belongs to Seadrift, TX, 3854 miles from this stretch, measured at 1.79 ft/yr. 1.4 miles up the coast, Makaha, HI shows the same lack of a significant trend.
Not this whole stretch, just Makaha itself: the Coastal Change Hazards Portal is USGS's own live version of this data.