Port St. Joe, FL Coastal Erosion Rate
Is the coast eroding 6 miles southwest of Port St. Joe, FL?
USGS's shoreline-change data puts this stretch, 6 miles southwest of Port St. Joe, FL, at 0.53 feet of erosion a year on average, a long-term rate for this specific ~3.5-mile section, not one storm's damage. At that rate, the shoreline has lost roughly 5.3 feet over the last decade.
The grain of this number
USGS surveys the coast in transects spaced a few hundred feet apart; this page groups the nearest ones into a single ~3.5-mile reading for the stretch closest to Port St. Joe, FL, rather than showing one arbitrary line. Segment center: 29.76, -85.38. Survey years: 2001, method LRR, from USGS's Gulf of Mexico shoreline-change assessment. That's how current the data is here, real, but not a live feed, since a shoreline survey is a major undertaking, not an annual check-in.
What 0.53 ft/yr means over time
Run 6 miles southwest of Port St. Joe, FL's 0.53 ft/yr rate forward 25 years and it implies about 13 feet of further retreat, assuming nothing changes, which is exactly the assumption a seawall or nourishment project exists to break.
How solid is this number
85 transects feed this segment's number; 100% of them individually measured retreat. USGS's confidence interval here is ±0.33 ft/yr. Sorted from fastest erosion to fastest growth across all 1211 measured segments nationally, this one lands at 291. Source: USGS Open-File Report 2004-1089. Bellport, NY sits at national rank 282 for erosion (0.56 ft/yr), one reference point among the 1211 scored segments, 1033 miles from here. Port St. Joe, FL, 1.8 miles off, is the adjacent measured stretch, reading slight erosion at 0.77 ft/yr.
Not this whole stretch, just Port St. Joe itself: the Coastal Change Hazards Portal is USGS's own live version of this data.