Grove City, FL Coastal Erosion Rate
What USGS measures 1.8 miles south of Grove City, FL
USGS's shoreline-change data puts this stretch, 1.8 miles south of Grove City, FL, at 3.02 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 30.2 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 Grove City, FL, rather than showing one arbitrary line. Segment center: 26.88, -82.32. 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 3.02 ft/yr means over time
Run 1.8 miles south of Grove City, FL's 3.02 ft/yr rate forward 25 years and it implies about 76 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
40 transects feed this segment's number; 100% of them individually measured retreat. Uncertainty on this specific number: 2.73 ft/yr either side. Sorted from fastest erosion to fastest growth across all 1211 measured segments nationally, this one lands at 93. Source: USGS Open-File Report 2004-1089. Goleta, CA sits at national rank 418 for erosion (0.28 ft/yr), one reference point among the 1211 scored segments, 2283 miles from here. Grove City, FL, 2 miles off, is the adjacent measured stretch, itself no significant trend.
Not this whole stretch, just Grove City itself: the Coastal Change Hazards Portal is USGS's own live version of this data.