Port St. Joe, FL Coastal Erosion Rate
Is the coast eroding 7.6 miles south of Port St. Joe, FL?
7.6 miles south of Port St. Joe, FL: USGS's transects didn't pick up a trend here that beats the survey's own uncertainty. That's the majority case nationally, and for this stretch specifically it means the coast is holding, not that the data failed to find anything.
What "Port St. Joe" means on this page
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 Port St. Joe, FL. Centered near 29.71°N, 85.30°W. The survey behind it runs to 2001, in USGS's Gulf of Mexico 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.
Where this fits nationally
73 transects feed this segment's number; 1% of them individually measured retreat. USGS's confidence interval here is ±0.49 ft/yr. Taken at face value, this segment's raw 0.28 ft/yr reading would land it 960 of 1211 nationally - a number worth ignoring, since it's statistical noise rather than a real trend. Source: USGS Open-File Report 2004-1089. For scale: Santiago, WA, 2397 miles away, ranks 1139 of 1211 nationally for growth, 1.48 ft/yr. Port St. Joe, FL, 3.1 miles off, is the adjacent measured stretch, reading slight accretion (beach growing) at 0.73 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.