Kailua, HI Coastal Erosion Rate
Is the coast eroding 1.6 miles southeast of Kailua, HI?
1.6 miles southeast of Kailua, HI: USGS's transects didn't pick up a trend here that beats the survey's own uncertainty. That's the majority case nationally, and for this stretch specifically it means the coast is holding, not that the data failed to find anything.
What this reading actually covers
This is a roughly 3.5-mile stretch of coast, not one address or parcel - USGS's own transects run every few hundred feet, but that's finer than any one property needs, so this page reports the stretch nearest Kailua, HI. Centered near 21.39°N, 157.71°W. USGS's Hawaii assessment last surveyed this stretch through 2007-2010, computing the rate with its WLR 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 157 individual transects averaged together, 64% of which measured erosion rather than growth. Uncertainty on this specific number: 0.31 ft/yr either side. Taken at face value, this segment's raw -0.07 ft/yr reading would land it 691 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 1057 nationally for growth belongs to West Sayville, NY, 4998 miles from this stretch, measured at 0.66 ft/yr. Kailua, HI, 2.1 miles off, is the adjacent measured stretch, reading slight accretion (beach growing) at 0.46 ft/yr.
One address near Kailua: the Coastal Change Hazards Portal zooms past this stretch to the underlying map.