Skip to content
New Orleans Concrete Leveling
News

Study: parts of New Orleans and its flood defenses are sinking up to 2 inches a year

By New Orleans Concrete Leveling ·

New Orleans Concrete Leveling tracks subsidence research because it’s the reason most concrete in this city sinks. The latest major study landed in June 2025.

What the study found

Researchers from Tulane University’s Department of River-Coastal Science and Engineering — lead author Simone Fiaschi, with Prof. Mead Allison — analyzed satellite radar data from 2002 to 2020 and published the results in Science Advances (Vol. 11, Issue 26, June 28, 2025), as reported by ScienceDaily. Key findings:

  • Some neighborhoods and wetlands are sinking more than 1 inch a year.
  • The fastest areas reach up to 47 millimeters — nearly 2 inches — a year.
  • Parts of the Hurricane and Storm Damage Risk Reduction System (HSDRRS), the $15 billion post-Katrina levee and floodwall network, are themselves sinking, and some floodwall sections are losing elevation faster than sea level is rising.

“In a city like New Orleans, where much of the land is already near sea level, even minor drops in elevation can increase flood risk,” Fiaschi said.

How it fits with earlier numbers

The finding lines up with what the City and NASA have reported. The City of New Orleans puts the city-wide average at about 0.2 inches a year, with parts of the city above 0.8 inches. NASA JPL’s 2016 study found up to 2 inches a year in industrial areas such as Michoud and Norco (NASA JPL). The new study extends the record to 2020 and puts the flood defenses themselves on the map.

What it means at home

The headline is about levees, but the mechanism is the same one under your driveway: uneven sinking. Ground that drops at different rates a few blocks — or a few feet — apart is what opens the lip between a driveway and a carport, pulls a walk away from a raised porch, and tips a patio back toward the house.

Three practical takeaways:

  1. Expect flatwork to keep moving. A leveled slab rides the ground; what makes it drop suddenly is water washing out support. See will my slab sink again?
  2. Control the water. Downspouts away from slab edges and sealed joints matter more on moving ground.
  3. On the fastest ground, think about weight. Lighter polyurethane foam adds far less load than slurry. See foam vs mudjacking.

The full local explanation is in why concrete sinks in New Orleans. For a free estimate on a slab that’s moved, call (504) 517-8336.

Call (504) 517-8336 — Free estimate