Lower Grand Lagoon, FL Coastal Erosion Rate
What USGS measures 4.4 miles southeast of Lower Grand Lagoon, FL
2.56 feet a year: that is the measured retreat rate USGS's transects show for the coast 4.4 miles southeast of Lower Grand Lagoon, FL, averaged across the full historical record surveyed here. At that rate, the shoreline has lost roughly 25.6 feet over the last decade.
What "Lower Grand Lagoon" means on this page
Nothing here is parcel-level. USGS's raw transects run every few hundred feet along the shore; this page averages the ones nearest Lower Grand Lagoon, FL into one ~3.5-mile reading rather than picking a single arbitrary line to represent the area. Centered near 30.12°N, 85.68°W. USGS's Gulf of Mexico assessment last surveyed this stretch through 2001, computing the rate with its LRR method. Other US regions were surveyed in different years, sometimes decades apart, so this page states its own rather than implying one national vintage.
25 years at this rate
If 2.56 ft/yr holds for the next 25 years, the coast 4.4 miles southeast of Lower Grand Lagoon, FL would retreat roughly 64 more feet, a projection, not a certainty: erosion rates shift with storms, sediment supply and any armoring built in the meantime.
Where this fits nationally
Averaging 63 separate transects produced this segment's rate, with 100% individually reading as erosion, rather than relying on any single survey line. The published margin on this reading runs ±2.25 ft/yr. Sorted from fastest erosion to fastest growth across all 1211 measured segments nationally, this one lands at 109. Source: USGS Open-File Report 2004-1089. Rank 118 nationally for erosion belongs to Port Mansfield, TX, 748 miles from this stretch, measured at 2.26 ft/yr, 0.9x this stretch's rate. Tyndall AFB, FL, 1.6 miles off, is the adjacent measured stretch, itself no significant trend.
One address near Lower Grand Lagoon: the Coastal Change Hazards Portal zooms past this stretch to the underlying map.