Triumph, LA Coastal Erosion Rate
Shoreline change 6.9 miles south of Triumph, LA
6.26 feet a year: that is the measured retreat rate USGS's transects show for the coast 6.9 miles south of Triumph, LA, averaged across the full historical record surveyed here. At that rate, the shoreline has lost roughly 62.6 feet over the last decade.
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 Triumph, LA into one ~3.5-mile reading rather than picking a single arbitrary line to represent the area. Centered near 29.24°N, 89.50°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 6.26 ft/yr holds for the next 25 years, the coast 6.9 miles south of Triumph, LA would retreat roughly 157 more feet, a projection, not a certainty: erosion rates shift with storms, sediment supply and any armoring built in the meantime.
How solid is this number
34 transects feed this segment's number; 100% of them individually measured retreat. Uncertainty on this specific number: 1.88 ft/yr either side. Sorted from fastest erosion to fastest growth across all 1211 measured segments nationally, this one lands at 41. Source: USGS Open-File Report 2004-1089. For scale: Virginia Beach, VA, 938 miles away, ranks 206 of 1211 nationally for erosion, 0.93 ft/yr, 0.1x this stretch's rate. 2.8 miles away, Buras, LA is the nearest other measured stretch: also no significant trend.
One address near Triumph: the Coastal Change Hazards Portal zooms past this stretch to the underlying map.