Monday, July 1, 2013

Orleans Avenue Canal Wall Gap

So, the Corps 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 that (levee boards, New Orleans Sewerage & Water Board [S&WB], etc.) that end up adding some complexities to construction.

The Corps eventually decides 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 build the canal walls on the 17th Street and London Ave. Canals.  There, fundamental flaws in the analysis of the soil strength (the sort that even an undergraduate in civil engineering should understand to avoid), will lead to their collapse.  

The Orleans Ave. Canal didn't fail like the others.  Why?  Well, that's sort of revealing.  Pumping Station Number 7 drains the area near Delgado and puts 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 they were to add walls lining the canal, the lake water could push up against the walls of the pumping station and (if they 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 says, 'we're broke, it's your project, you fix the structure, since it's hurricane protection and not internal drainage' [this is in ~80's-early 90's, so the S&WB was pretty broke].  The Corps and the S&WB then get into a big pissing contest.  Meanwhile, the walls are going up.  Eventually, they reach the section nearest PS#7 and they just stop 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.  

This gap is still there today:

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!  

Now, I'm actually an engineer with some experience.  I actually see the situation 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 (usually 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.  The gap continues to be a monument to "not my job" syndrome ( ).  

I'm not making any of this up.  When ASCE came to town to write their Katrina report, they specifically highlighted the Orleans Ave. Canal Gap debacle as a symbol of how it was "a system in name only":
(~page 64.) . You can go there and see it for yourself, too. It's near where 610 crosses over the canal. Drive down the west edge of City Park and look for yourself.

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

Also, test post from Blogger App. Not sure how it will work.

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