Rhode Island's south shore is a chain of barrier beaches with salt ponds behind them — and the ocean is pushing them landward. Most erode a few feet a year; Matunuck has averaged over 4 ft a year since 1939, enough to put a public road and a water main on the brink. Here is the measured record.
Rates come from the CRMC regulatory Shoreline Change Maps (Watch Hill to Little Compton and Block Island) and the USGS National Assessment of Shoreline Change, which put the New England South sub-region at a long-term net −0.2 m/yr with 84% of transects eroding and its single worst transect, −1.4 m/yr, at East Matunuck State Beach. Rhode Island has no single statewide ft/yr figure — rates are mapped per barrier segment. For the exact rate and base flood elevation at one parcel, see the address certificate.
How fast is Rhode Island's south shore eroding?
The barrier beaches erode on the order of 1 to 5 ft/yr, and Matunuck — the worst — has averaged over 4 ft/yr since 1939 (CRMC), matched by the USGS maximum of −1.4 m/yr (~−4.6 ft/yr) at East Matunuck State Beach.
Does Rhode Island map shoreline change?
Yes — the CRMC maintains regulatory Shoreline Change Maps (Watch Hill to Little Compton and Block Island) built on URI beach surveys, and the STORMTOOLS viewer maps surge and sea-level-rise inundation across the state's ~420 miles of coast.
Why is Matunuck such a problem?
Matunuck Beach Road — the only land access for a neighborhood and the route of a buried water main — sits on a headland retreating more than 4 ft a year, which drove the contested seawall the CRMC ultimately approved.
Is sea level rising in Rhode Island?
Yes — NOAA's Newport gauge shows +2.97 mm/yr (1930–2024), about a foot per century, and the CRMC plans to the NOAA 2017 high curve of more than 9 ft of rise by 2100.
What FEMA flood zone are the Rhode Island barriers in?
The ocean-fronting dunes of Misquamicut, Charlestown, Green Hill and Matunuck are mapped Zone VE (high-hazard wave zone), transitioning to Zone AE across the barrier flats and pond margins — confirm any parcel on FEMA's National Flood Hazard Layer.
A barrier beach is supposed to migrate — it rolls landward as the sea rises, overwashing into the pond behind it. That is fine until a road, a water main and a row of houses are built on top of it. Rhode Island's south shore is the textbook case, and Matunuck is where the conflict came to a head.
This page is the Rhode Island overview. The $99 Psammite certificate reads your exact address: the long-term erosion rate at your parcel, your storm-surge and FEMA exposure, the uncertainty band, and whether a licensed site review is warranted — built from the same CRMC, USGS, NOAA and FEMA record.