Bolivar Peninsula, TX Coastal Erosion Rate
What USGS measures 3.6 miles northeast of Bolivar Peninsula, TX
Averaged across every transect USGS ran 3.6 miles northeast of Bolivar Peninsula, TX, the shoreline has been moving inland at 1.29 feet a year, a real measured rate, not a regional estimate applied to this stretch. At that rate, the shoreline has lost roughly 12.9 feet over the last decade.
The grain of this number
Bolivar Peninsula, TX is the nearest named place, 3.6 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: 29.52, -94.52. 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 1.29 ft/yr means over time
Run 3.6 miles northeast of Bolivar Peninsula, TX's 1.29 ft/yr rate forward 25 years and it implies about 32 feet of further retreat, assuming nothing changes, which is exactly the assumption a seawall or nourishment project exists to break.
What backs this reading up
Averaging 13 separate transects produced this segment's rate, with 100% individually reading as erosion, rather than relying on any single survey line. USGS's confidence interval here is ±0.36 ft/yr. This segment ranks 178 of 1211 measured US coastal segments, ordered from fastest erosion to fastest growth. Source: USGS Open-File Report 2004-1089. For scale: West Ocean City, MD, 1262 miles away, ranks 85 of 1211 nationally for erosion, 3.43 ft/yr, 2.7x this stretch's rate. Bolivar Peninsula, TX, 1.8 miles off, is the adjacent measured stretch, reading slight erosion at 0.73 ft/yr.
Bolivar Peninsula, TX on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.