Why Some US Coastline Is Growing, Not Eroding

Erosion and accretion are the same process, in reverse

A shoreline moves because sediment - sand, silt - is either removed faster than it arrives (erosion) or arrives faster than it's removed (accretion, sometimes called growth). Both are driven by the same things: currents, wave direction, storm frequency, and how much sediment a river or updrift beach is supplying. USGS measures both with the same method and the same confidence interval.

What growth looks like in practice

Ocean Shores, WA is the fastest measured growth in this dataset, sediment accumulating rather than washing away - a real, if less common, pattern.

Why erosion dominates the headlines anyway

Significant erosion outnumbers significant accretion across the segments this site covers, which tracks with the broader pattern in USGS's own national assessments: net sediment supply to most US coastlines has fallen as dams and hardened shorelines interrupt the natural flow of sand, so accretion is the less common outcome even where it does happen.

A growing shoreline still isn't a guarantee

Accretion measured over a multi-decade average doesn't rule out short-term erosion from a single severe storm, and a region's survey vintage (see the survey vintage guide) means even a growing trend could have reversed since the last measurement.

Where to go next

See the range this plays out across: Golden Meadow, LA, Dauphin Island, AL, Ocean Shores, WA.

How CoastErosionCheck Calculates a Coast's Erosion Rate · What "No Significant Trend" Actually Means