Rockaway Beach, OR Coastal Erosion Rate
Is the coast eroding 2.3 miles north of Rockaway Beach, OR?
Unusual good news for this stretch: the shoreline 2.3 miles north of Rockaway Beach, OR has grown by a measured 1.15 feet a year on average, per USGS's long-term transect data for this section. At that rate, the shoreline has gained roughly 11.5 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 Rockaway Beach, OR. Centered near 45.65°N, 123.94°W. USGS's Pacific Northwest assessment last surveyed this stretch through 2002-2011, computing the rate with its LRR method. Other US regions were surveyed in different years, sometimes decades apart, so this page states its own rather than implying one national vintage.
25 years at this rate
Holding the 1.15 ft/yr accretion rate 2.3 miles north of Rockaway Beach, OR for 25 years would add roughly 29 feet of shoreline, again assuming nothing about the local sediment supply changes.
What backs this reading up
101 transects feed this segment's number; 37% of them individually measured retreat. Uncertainty on this specific number: 0.85 ft/yr either side. Among the 1211 US coastal segments with a measurable trend, this one ranks 1120 for erosion, 1 being the fastest-retreating coast in the dataset. Source: USGS Open-File Report 2012-1008. Rank 1171 nationally for growth belongs to Avalon, NJ, 2512 miles from this stretch, measured at 2.37 ft/yr, 2.1x this stretch's rate. 3.5 miles away, Manzanita, OR is the nearest other measured stretch: accretion (beach growing) at 1.28 ft/yr.
One address near Rockaway Beach: the Coastal Change Hazards Portal zooms past this stretch to the underlying map.