Ilwaco, WA Coastal Erosion Rate
Is the coast eroding 3.7 miles southwest of Ilwaco, WA?
The coast 3.7 miles southwest of Ilwaco, WA has been retreating at a measured 10.32 feet a year, USGS's own long-term rate for this stretch, built from historical shoreline positions rather than a single survey. At that rate, the shoreline has lost roughly 103.2 feet over the last decade.
The grain of this number
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 Ilwaco, WA. Centered near 46.27°N, 124.08°W. The survey behind it runs to 2002-2011, in USGS's Pacific Northwest assessment, using the LRR method. Shoreline surveys aren't repeated every year, so this is the most recent long-term measurement USGS has published for this coast, not a live reading.
25 years at this rate
If 10.32 ft/yr holds for the next 25 years, the coast 3.7 miles southwest of Ilwaco, WA would retreat roughly 258 more feet, a projection, not a certainty: erosion rates shift with storms, sediment supply and any armoring built in the meantime.
How solid is this number
Averaging 17 separate transects produced this segment's rate, with 100% individually reading as erosion, rather than relying on any single survey line. Uncertainty on this specific number: 3.22 ft/yr either side. This segment ranks 22 of 1211 measured US coastal segments, ordered from fastest erosion to fastest growth. Source: USGS Open-File Report 2012-1008. For scale: Virginia Beach, VA, 2536 miles away, ranks 111 of 1211 nationally for erosion, 2.4 ft/yr, 0.2x this stretch's rate. 0.4 miles up the coast, Ilwaco, WA shows 6.42 ft/yr of eroding.
Ilwaco, WA on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.