Don't hold your breath looking for the environmental movement to get any blame.
A bit of background Here, and here.
I'm sure there's more of this kind of thing over the past decades. It would be extremely difficult to make a case that this kind of obstruction was not at least as big an influence as Corps of Engineers funding issues were.
BTW, look for environmentalists to make a big stink about how the water being pumped out of New Orleans is going to hurt the fish in the lake.
(Via Coldfury.com)