Robert G. Bea of the University of California at Berkeley says his recent tour turned up several areas of concern but the most troubling was erosion on a 13-mile levee by the Mississippi River Gulf Outlet, The New York Times reports.
Breaches in that levee helped channel water into New Orleans during Hurricane Katrina, devastating communities in St. Bernard Parish just east of the city.
The rapid reconstruction of the levee after Katrina was hailed as one of the U.S. Army Corps of Engineers most significant rebuilding achievements.
But Bea says the erosion furrows, or rills, he saw in March suggest the "risks are still high" that heavy storms could cause them to tear.
While Corps officials argue Bea is overstating the risk, they plan to re-inspect elements of the levee system and fix any problems they find.