Dulac, LA Coastal Erosion Rate
What USGS measures 23.7 miles south of Dulac, LA
Averaged across every transect USGS ran 23.7 miles south of Dulac, LA, the shoreline has been moving inland at 11.04 feet a year, a real measured rate, not a regional estimate applied to this stretch. At that rate, the shoreline has lost roughly 110.4 feet over the last decade.
What this reading actually covers
Dulac, LA is the nearest named place, 23.7 miles away, to a ~3.5-mile stretch of coast USGS has surveyed - the reading below covers that whole stretch, not a single property in it. Segment center: 29.06, -90.75. 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 11.04 ft/yr means over time
Run 23.7 miles south of Dulac, LA's 11.04 ft/yr rate forward 25 years and it implies about 276 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
Averaging 91 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: 2.98 ft/yr either side. This segment ranks 20 of 1211 measured US coastal segments, ordered from fastest erosion to fastest growth. Source: USGS Open-File Report 2004-1089. For scale: Oak View, CA, 1717 miles away, ranks 573 of 1211 nationally for erosion, 0.15 ft/yr, a small fraction of this stretch's own rate. 2.4 miles away, Dulac, LA is the nearest other measured stretch: severe erosion at 9.75 ft/yr.
Dulac, LA on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.