Lower Ninth Ward Levee Breaches in 2005
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Pre-Katrina, the area immediately in front of the east breaches of the Inner Harbor Navigation Canal (a.k.a. the Industrial Canal) was a dense, thriving neighborhood of primarily African American lower- to middle-class homeowners. Houses in this neighborhood, called the Lower Ninth Ward, were built right up to the canal walls and were shaded by huge oaks, cypresses, and pecans.
On August 29, 2005, at about 5 a.m., a section of the I-wall south of the Florida Avenue bridge began to breach. At this time, the water level was still below the top of the floodwalls. This first breach occurred not far from a Sewerage and Water Board drainage pump station (PS#5). Station operators elsewhere in the city listened to the PS#5 operators describe the problem and beg for help. More than one post-Katrina study determined this particular failure was due to water seeping beneath the canal walls which caused the wall to move and fail.
At about 7:45 a.m., a second breach occurred about six blocks to the south and eventually widened into a 1,000 foot gap. Floodwaters from the two breaches combined to submerge the city's entire Lower Ninth Ward, killing hundreds (directly and indirectly) and destroying commercial buildings, homes and infrastructure. Eighty-four bodies were recovered from areas directly flooded by the breach this breach of the Industrial Canal.
The water from the two east breaches also flowed into the cities of Arabi and Chalmette in adjacent St. Bernard Parish. Floodwaters from two breaches on the western side of the Industrial Canal combined with floodwaters released from the 17th Street and London Avenue Canals to flood most of the City's main basin.
Before the storm, an empty barge owned by Ingram Marine had been moored across from the area that would become one of the breach sites. At some point, it came loose, and after Katrina's winds and the eye had passed into Mississippi, the barge was pushed across the Industrial Canal. It then floated through the southeast breach and was deposited in the Lower Ninth Ward.
Post-Katrina studies concluded that the southeast I-wall and the northwest I-wall were overtopped by floodwaters. Failures occurred when the water level was estimated to be 1.7 feet above the tops of the floodwalls and levees.
Studies also determined that earthen levees without I-walls all around the city, including the southwest breach, were overtopped by a storm surge. Out of the 50 estimated levee breaches system-wide, the majority can be attributed to overtopping and erosion. In other words, the water scoured away soil from the land-side and washed it away, causing the I-wall to fail.
Today, the adjacent land is largely vacant of homes and buildings. Many foundations or slabs where homes once stood are all that remain. All trees have been removed either due to the initial flooding or due to removal by governmental agencies post-Katrina.
