Copalis Beach, WA Coastal Erosion Rate
Is the coast eroding 0.8 miles southwest of Copalis Beach, WA?
Unusual good news for this stretch: the shoreline 0.8 miles southwest of Copalis Beach, WA has grown by a measured 3.87 feet a year on average, per USGS's long-term transect data for this section. At that rate, the shoreline has gained roughly 38.7 feet over the last decade.
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 Copalis Beach, WA. Centered near 47.12°N, 124.18°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
Holding the 3.87 ft/yr accretion rate 0.8 miles southwest of Copalis Beach, WA for 25 years would add roughly 97 feet of shoreline, again assuming nothing about the local sediment supply changes.
What backs this reading up
29 transects feed this segment's number; 0% of them individually measured retreat. The published margin on this reading runs ±0.62 ft/yr. This segment ranks 1190 of 1211 measured US coastal segments, ordered from fastest erosion to fastest growth. Source: USGS Open-File Report 2012-1008. Rank 1077 nationally for growth belongs to Florence, OR, 219 miles from this stretch, measured at 0.8 ft/yr, 0.2x this stretch's rate. Ocean City, WA, 1.5 miles off, is the adjacent measured stretch, reading accretion (beach growing) at 4.1 ft/yr.
Not this whole stretch, just Copalis Beach itself: the Coastal Change Hazards Portal is USGS's own live version of this data.