Farther down the river, there is the Old River Control Structure, which was built to keep the Atchafalaya Basin from capturing too much of the Mississippi’s flow.
Flooding in 1973 undercut the enormous structure and threatened to wash it away. But improvements in subsequent years and additional facilities have lessened the risk to an extent that experts have expressed little concern about it. They also suggested that it might serve to temporarily divert more of the Mississippi’s waters in the worst of the flood.
Below the Old River Control Structure come two additional spillways — the Morganza and Bonnet Carré — that can release water from the Mississippi’s flow.
The corps is likely to open the gates on both of those structures. The Morganza can send 600,000 cubic feet of water per second down the Atchafalaya Basin; it has not been used since the floods of 1973.
And then there's this.
Don T. Riley, a former deputy chief of engineers for the corps and a retired major general, expressed confidence in the ability of the Mississippi’s flood control systems to deal with tremendous volumes of water.
But he said tributary flooding was a continuing concern, and parts of the main river control system had not yet been completed to the maximum height and strength called for in the corps’ plans.
Though the system is hardy and resilient, Mr. Riley said, “there’s going to be big concern all the way down the river — if more rains come, all bets are off.”
Keep an eye on the weather, I guess.