Dulac, LA Coastal Erosion Rate
What USGS measures 22.9 miles south of Dulac, LA
9.75 feet a year: that is the measured retreat rate USGS's transects show for the coast 22.9 miles south of Dulac, LA, averaged across the full historical record surveyed here. At that rate, the shoreline has lost roughly 97.5 feet over the last decade.
The grain of this number
Nothing here is parcel-level. USGS's raw transects run every few hundred feet along the shore; this page averages the ones nearest Dulac, LA into one ~3.5-mile reading rather than picking a single arbitrary line to represent the area. Centered near 29.07°N, 90.71°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 9.75 ft/yr holds for the next 25 years, the coast 22.9 miles south of Dulac, LA would retreat roughly 244 more feet, a projection, not a certainty: erosion rates shift with storms, sediment supply and any armoring built in the meantime.
What backs this reading up
Averaging 68 separate transects produced this segment's rate, with 100% individually reading as erosion, rather than relying on any single survey line. Uncertainty on this specific number: 4.14 ft/yr either side. Sorted from fastest erosion to fastest growth across all 1211 measured segments nationally, this one lands at 23. Source: USGS Open-File Report 2004-1089. For scale: Lower Grand Lagoon, FL, 310 miles away, ranks 109 of 1211 nationally for erosion, 2.56 ft/yr, 0.3x this stretch's rate. 1.7 miles away, Dulac, LA is the nearest other measured stretch: severe erosion at 7.19 ft/yr.
Not this whole stretch, just Dulac itself: the Coastal Change Hazards Portal is USGS's own live version of this data.