South Padre Island, TX Coastal Erosion Rate
Is the coast eroding 5.5 miles south of South Padre Island, TX?
The coast 5.5 miles south of South Padre Island, TX is actually gaining ground, not losing it: USGS's transects measure 1.46 feet of accretion a year here, sediment building up rather than washing away. At that rate, the shoreline has gained roughly 14.6 feet over the last decade.
What "South Padre Island" means on this page
USGS surveys the coast in transects spaced a few hundred feet apart; this page groups the nearest ones into a single ~3.5-mile reading for the stretch closest to South Padre Island, TX, rather than showing one arbitrary line. Segment center: 26.04, -97.17. 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.
What 1.46 ft/yr means over time
Holding the 1.46 ft/yr accretion rate 5.5 miles south of South Padre Island, TX for 25 years would add roughly 37 feet of shoreline, again assuming nothing about the local sediment supply changes.
How solid is this number
Averaging 65 separate transects produced this segment's rate, with 0% individually reading as erosion, rather than relying on any single survey line. The published margin on this reading runs ±0.34 ft/yr. This segment ranks 1138 of 1211 measured US coastal segments, ordered from fastest erosion to fastest growth. Source: USGS Open-File Report 2004-1089. North Wildwood, NJ sits at national rank 1193 for growth (4.21 ft/yr), one reference point among the 1211 scored segments, 1574 miles from here. 2.1 miles away, South Padre Island, TX is the nearest other measured stretch: also no significant trend.
South Padre Island, TX on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.