Seal Beach, CA Coastal Erosion Rate
What USGS measures 2.2 miles southwest of Seal Beach, CA
Unusual good news for this stretch: the shoreline 2.2 miles southwest of Seal Beach, CA has grown by a measured 0.73 feet a year on average, per USGS's long-term transect data for this section. At that rate, the shoreline has gained roughly 7.3 feet over the last decade.
What this reading actually covers
Nothing here is parcel-level. USGS's raw transects run every few hundred feet along the shore; this page averages the ones nearest Seal Beach, CA into one ~3.5-mile reading rather than picking a single arbitrary line to represent the area. Centered near 33.74°N, 118.10°W. The survey behind it runs to 1852-2016, in USGS's California 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.
25 years at this rate
Holding the 0.73 ft/yr accretion rate 2.2 miles southwest of Seal Beach, CA for 25 years would add roughly 18 feet of shoreline, again assuming nothing about the local sediment supply changes.
Where this fits nationally
This reading comes from 67 individual transects averaged together, 6% of which measured erosion rather than growth. USGS's confidence interval here is ±0.62 ft/yr. Among the 1211 US coastal segments with a measurable trend, this one ranks 1072 for erosion, 1 being the fastest-retreating coast in the dataset. Source: USGS National Shoreline Change data release (ScienceBase, DOI 10.5066/P94J0K7Z), Kratzmann 2024 / Data Report 1187. For scale: Newport Beach, CA, 15 miles away, ranks 1098 of 1211 nationally for growth, 0.94 ft/yr, 1.3x this stretch's rate. 1.8 miles up the coast, Seal Beach, CA shows 0.63 ft/yr of accreting.
One address near Seal Beach: the Coastal Change Hazards Portal zooms past this stretch to the underlying map.