[kingu]

Did someone try to put 10 pounds in a 5 pound bag?

Off subject, but I thought I'd note you can very clearly see these pipes and the pumping station on Google Earth (610/10 interchange).. Back on topic. Obviously, this is what the end result was. Looking at Google, I see a lot of huge trees next to the concrete clad earthen levee. I'd hazard a guess that those trees were blown over, the gap where the roots were (and the pulling of the roots) weakened the earth backing of the levee, and when they started pumping all the water into the canal, they created enough pressure to destroy it.

Just making a guess here, but that seems to me to be the likely scenario. Especially if the break turns out to be between 18th street and 14th street.

[Amelia]

I'd hazard a guess that those trees were blown over, the gap where the roots were (and the pulling of the roots) weakened the earth backing of the levee, and when they started pumping all the water into the canal, they created enough pressure to destroy it.

In Georgia, we're told not to have trees on earthen dams for just that reason.