Port Mansfield, TX Coastal Erosion Rate
What USGS measures 10.8 miles east of Port Mansfield, TX
Averaged across every transect USGS ran 10.8 miles east of Port Mansfield, TX, the shoreline has been moving inland at 1.53 feet a year, a real measured rate, not a regional estimate applied to this stretch. At that rate, the shoreline has lost roughly 15.3 feet over the last decade.
What this reading actually covers
Port Mansfield, TX is the nearest named place, 10.8 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: 26.51, -97.28. The survey behind it runs to 2001, in USGS's Gulf of Mexico assessment, using the LRR method. Shoreline surveys aren't repeated every year, so this is the most recent long-term measurement USGS has published for this coast, not a live reading.
What 1.53 ft/yr means over time
Run 10.8 miles east of Port Mansfield, TX's 1.53 ft/yr rate forward 25 years and it implies about 38 feet of further retreat, assuming nothing changes, which is exactly the assumption a seawall or nourishment project exists to break.
Where this fits nationally
65 transects feed this segment's number; 100% of them individually measured retreat. USGS's confidence interval here is ±1.28 ft/yr. This segment ranks 157 of 1211 measured US coastal segments, ordered from fastest erosion to fastest growth. Source: USGS Open-File Report 2004-1089. Rank 265 nationally for erosion belongs to Broadmoor, CA, 1659 miles from this stretch, measured at 0.61 ft/yr, 0.4x this stretch's rate. 1.9 miles away, Port Mansfield, TX is the nearest other measured stretch: moderate erosion at 1.99 ft/yr.
Port Mansfield, TX on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.