Ko Olina, HI Coastal Erosion Rate
Shoreline change 1.8 miles northwest of Ko Olina, HI
USGS's shoreline-change data puts this stretch, 1.8 miles northwest of Ko Olina, HI, at 0.41 feet of erosion a year on average, a long-term rate for this specific ~3.5-mile section, not one storm's damage. At that rate, the shoreline has lost roughly 4.1 feet over the last decade.
What this reading actually covers
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 Ko Olina, HI, rather than showing one arbitrary line. Segment center: 21.36, -158.13. 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 0.41 ft/yr means over time
Run 1.8 miles northwest of Ko Olina, HI's 0.41 ft/yr rate forward 25 years and it implies about 10 feet of further retreat, assuming nothing changes, which is exactly the assumption a seawall or nourishment project exists to break.
Where this fits nationally
Averaging 52 separate transects produced this segment's rate, with 100% individually reading as erosion, rather than relying on any single survey line. The published margin on this reading runs ±0.16 ft/yr. This segment ranks 346 of 1211 measured US coastal segments, ordered from fastest erosion to fastest growth. Source: USGS Open-File Report 2011-1009. Virginia Beach, VA sits at national rank 249 for erosion (0.65 ft/yr), one reference point among the 1211 scored segments, 4930 miles from here. 2.3 miles up the coast, Nanakuli, HI shows the same lack of a significant trend.
Not this whole stretch, just Ko Olina itself: the Coastal Change Hazards Portal is USGS's own live version of this data.