Waimanalo Beach, HI Coastal Erosion Rate
What USGS measures 1.3 miles northwest of Waimanalo Beach, HI
The coast 1.3 miles northwest of Waimanalo Beach, 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 "Waimanalo Beach" means on this page
Nothing here is parcel-level. USGS's raw transects run every few hundred feet along the shore; this page averages the ones nearest Waimanalo Beach, HI into one ~3.5-mile reading rather than picking a single arbitrary line to represent the area. Centered near 21.35°N, 157.70°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.
Where this fits nationally
This reading comes from 308 individual transects averaged together, 32% of which measured erosion rather than growth. Uncertainty on this specific number: 0.26 ft/yr either side. Taken at face value, this segment's raw 0.09 ft/yr reading would land it 845 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 990 nationally for growth belongs to Fort Myers Beach, FL, 4730 miles from this stretch, measured at 0.39 ft/yr. 2.8 miles away, Kailua, HI is the nearest other measured stretch: also no significant trend.
One address near Waimanalo Beach: the Coastal Change Hazards Portal zooms past this stretch to the underlying map.