Florence, OR Coastal Erosion Rate
Is the coast eroding 3.3 miles southwest of Florence, OR?
Unusual good news for this stretch: the shoreline 3.3 miles southwest of Florence, OR has grown by a measured 0.8 feet a year on average, per USGS's long-term transect data for this section. At that rate, the shoreline has gained roughly 8 feet over the last decade.
The grain of this number
Nothing here is parcel-level. USGS's raw transects run every few hundred feet along the shore; this page averages the ones nearest Florence, OR into one ~3.5-mile reading rather than picking a single arbitrary line to represent the area. Centered near 43.95°N, 124.14°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 0.8 ft/yr accretion rate 3.3 miles southwest of Florence, OR for 25 years would add roughly 20 feet of shoreline, again assuming nothing about the local sediment supply changes.
What backs this reading up
Averaging 112 separate transects produced this segment's rate, with 7% individually reading as erosion, rather than relying on any single survey line. USGS's confidence interval here is ±0.72 ft/yr. Among the 1211 US coastal segments with a measurable trend, this one ranks 1077 for erosion, 1 being the fastest-retreating coast in the dataset. Source: USGS Open-File Report 2012-1008. Marina del Rey, CA sits at national rank 1118 for growth (1.07 ft/yr), one reference point among the 1211 scored segments, 755 miles from here. Dunes City, OR, 3.3 miles off, is the adjacent measured stretch, reading slight accretion (beach growing) at 0.67 ft/yr.
One address near Florence: the Coastal Change Hazards Portal zooms past this stretch to the underlying map.