Jul 1, 2025 - Environment

Some of New Orleans is sinking faster than sea level rise

Chelsea Brasted

Illustration of a cracked emergency siren with a large ocean wave inside. — Illustration: Maura Losch/Axios

Parts of New Orleans, including some of its flood protections, are sinking faster than the sea level is rising beyond it, according to a new study from Tulane University.

Why it matters: The study offers "a wake-up call," said study co-author Mead Allison in a press release, as the margin between what protects New Orleans and the water that threatens it narrows.

"We need ongoing monitoring and maintenance to ensure that our flood defenses don't lose their level of protection beneath us,"Allison said.

The latest: "Some neighborhoods, wetlands and even sections of floodwalls are sinking by more than an inch per year — with some areas experiencing up to [nearly 2 inches] of elevation loss annually," the press release says.

Among the parts of the city that are sinking are some of the concrete floodwalls and levees installed after Hurricane Katrina.
Plus, some wetlands east of the city, which are a key part of storm protection for New Orleans, could turn into open water within a decade.

How they did it: The researchers used a remote sensing technique called interferometric synthetic aperture radar. The technology allowed researchers to detect changes down to the millimeter, according to a press release.

Using satellite radar data, they were able to track ground elevation shifts across the metro between 2002 and 2020.

Go deeper: Read the study as published in Science Advances.

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Some of New Orleans is sinking faster than sea level rise

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