Cross-posted at NOLA-dishu

Photo credit: Derek Bridges. Gap in Orleans Avenue canal wall below I-610; Pumping Station Number 7 in background. 

So, the Army Corps of Engineers was in charge of building a hurricane protection system around New Orleans, as ordered by Congress in response to Hurricane Betsy. There are a lot of interlocking political entities–levee boards, New Orleans Sewerage & Water Board (S&WB), etc.–that end up adding layers of complexities to such construction.

The Corps eventually decided to build walls along the outfall canals (instead of moving the pumping stations to the lake; that’s a HUGE issue all on its own that I won’t touch on for now). They built the canal walls on the 17th Street and London Avenue Canals. There, fundamental flaws in the analysis of the soil strength (the sort that even an undergraduate in civil engineering should understand to avoid), eventually led to their collapse.

But the Orleans Avenue Canal didn’t fail like the others. Why? Well, that’s sort of revealing. Pumping Station Number 7 (PS#7) drains the area near Delgado Community College and directs water into the Orleans Canal to bring it to the lake. That pumping station is a masonry structure built all the way back when Albert Baldwin Wood was running the S&WB. Masonry is relatively weak and brittle. Since that structure is the closest to the lake out of all the pumping stations, if walls were added to line the canal, the lake water could push up against the walls of the pumping station and, if the water rose high enough, collapse the walls of the pumping station. That would be bad.

Fortunately, the Corps & S&WB realized this. The Corps requested the S&WB reinforce their structure. The S&WB essentially said, “We’re broke, it’s your project, you fix the structure, since it’s hurricane protection and not internal drainage” (this was in the 1980s-early 90s, so the S&WB was truly pretty broke). The Corps and the S&WB then got into a big pissing contest. Meanwhile, the walls started going up. Eventually, they reached the section nearest PS#7 and they just stopped building the wall. About a 300′ gap is left–that way, if waters rise, it won’t put undue pressure on the walls of PS#7.

The gaps are still there today:

Clay floodwall

Photo credit: Clay Kirby

Orleans Ave canal floodwall gap_3

Photo credit: Derek Bridges

Orleans Ave canal floodwall gap_5

Photo credit: Derek Bridges

The thing is about this gap is it renders basically the entire wall useless! The wall provides basically no protection for the city, despite several million dollars spent on its construction. The reason the Orleans Ave. walls didn’t fail is because they were never holding anything back!

not my job

Now, I’m actually an engineer with some experience. I see the predicament the engineers were in. Situations with ambiguous boundaries and split responsibilities happen. You rarely know exactly what the final project is going to look like before you begin. When you have a gap, you sit down and figure out whose responsibility it is. Engineers have lots of meetings ... Usually, someone just mans up and takes it over (typically the one with the biggest budget). It’s a serious sign of how much of a cluster the levees were before Katrina that there was never resolution on this issue. And the gap remains a monument to “not my job” syndrome.

I’m not making any of this up. When the American Society of Civil Engineers (ASCE) came to town to write their Katrina report (Hurricane Katrina: What Went Wrong and Why), they specifically highlighted the Orleans Ave. Canal Gap debacle as a symbol of how it was “a system in name only” (see page 64). You can go there and see it for yourself, too. It’s near where I-610 crosses over the canal. Drive down the west edge of City Park and take a look.

Also, see Matt McBride’s latest post at Fix the Pumps.

Clay Kirby is a mechanical engineer and lives New Orleans, LA.

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