Upper Grand Lagoon, FL Coastal Erosion Rate
What USGS measures 3.8 miles northwest of Upper Grand Lagoon, FL
The coast 3.8 miles northwest of Upper Grand Lagoon, FL shows no statistically significant trend either way. USGS's transects measured a rate here, but it's smaller than the survey's own margin of error for this stretch, so calling it "eroding" or "growing" would overstate what the data actually shows.
What this reading actually covers
Nothing here is parcel-level. USGS's raw transects run every few hundred feet along the shore; this page averages the ones nearest Upper Grand Lagoon, FL into one ~3.5-mile reading rather than picking a single arbitrary line to represent the area. Centered near 30.20°N, 85.80°W. 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.
How solid is this number
113 transects feed this segment's number; 0% of them individually measured retreat. Uncertainty on this specific number: 0.51 ft/yr either side. Taken at face value, this segment's raw 0.34 ft/yr reading would land it 976 of 1211 nationally - a number worth ignoring, since it's statistical noise rather than a real trend. Source: USGS Open-File Report 2004-1089. Rank 1124 nationally for growth belongs to Santa Monica, CA, 1925 miles from this stretch, measured at 1.21 ft/yr. Panama City Beach, FL, 2.3 miles off, is the adjacent measured stretch, itself no significant trend.
Upper Grand Lagoon, FL on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.