Sunday, May 15, 2011

Bonnet Carre Spillway

The actual big news this weekend was the opening of the other spillway, the Morganza Spillway.  bonne carre signThe  Morganza is above Baton Rouge and the Bonnet Carre is between Baton Rouge and New Orleans.  New Orleans is downriver from Baton Rouge. 
air of carniva;Frank and I went to the Exterran Picnic in Destrehan at Ormond Plantation on Saturday.  One of the big draws for me to go was the proximity of Bonnet Carre.  I wanted to see it.  At Bonnet Carre, it was the atmosphere of a carnival.  Cars were parked up and down the River Road, people were riding motorcycles and bicycles, walking.  All either heading toward or from the Spillway weir.  The Army Corps of Engineers had set up a tent at the site, I guess to make sure no idiots fell in, and they were answering questions, offering information and keeping theinfo board peace.
The board said that on Saturday there were 264 bays open, and the total flow of water through the weir was 258,000 cfs or cubic feet per second.  The incredible thing to see was how fast the water was rushing by.  Such power. 
On the River Road are the large refineries, Norco is where they all line the levee and use the Mississippi River to move their product and provide electricity for their production.  Here are three you can just about touch from the road.
Motiva, Shell Chemicals and Hexion.  Dow is across the hexion

river side of spillway
Here you are looking at the Spillway Weir from the river side.  This structure was completed in 1931 in response to the Great Flood of 1927.  Prior to 1927 the Mississippi River Commission thought they only needed the levees as flood controls. 
The Bonnet Carre weir structure is 32.8 miles from New Orleans.  It is 7000 feel long with 350 bays of 20 feet each.  There are 20 timbers in each bay.  The Spillway is opened approx. every 10 years. 

This is the top of the weir.  It has a rail that holds two cranes to lift the timbers.  The timbers are then placed on top of the rails to facilitate their replacement in closing the top 1 weir top
See the timbers across the top?  I will show you the front in a minutes.  Where the timbers end that bay still has the timbers in place.  The water always leaks through the weir providing some water to the spillway and thus Lake Pontchartrain all the time.  However the water level and pressure behind the weir is not usually this great. 

Look at the bay with the timbers in place here:

water thru boards
The Bonnet Carre Spillway was built at the site of the Bonnet Carre Crevasse, a 3000 foot wide break in the levee.  The water flows into the spillway for  nearly 6 miles before reaching Lake Pontchartrain which eventually drains out to the Gulf of Mexico through the Rigoletes (pronounced rig-o-lees).  We used to swim there as kids.
Here is the Weir from the other side.rushing waters What you can’t see is the tremendous power of that water as it rushes through.  And it is muddy and brown, like we are used to seeing our rivers and swamps. rushing water rushing water 1

rushing down from the backside  The guguageage says  22 feet

boat launch
On the way home we crossed the Spillway on Hwy 61 which is the old way people would go from New Orleans to Laplace and eventually to Baton Rouge.  The Spillway there is dry and is used for recreational activities.  This is the boat launch area now underwater.  And to see just how much water here is the picnic shelter we used when we met my brother’s family there about 8 years ago.picnic structure
I have added some pictures of the water in the Spillway along Hwy 61 as we headed home. 
Frank keeps using the word “historic”  and I guess this is an historic event.  The Morganza Spillway has only been opened once before and now to have two of them opening is pretty historic. 
I will have more on the Morganza if I can.  It is north of us and accessible only by a  small highway road.  They were closing the area on Saturday, so they didn’t want tourists like they have at Bonnet Carre. 
telephone poles boat launch highway1 highway2 land covered tele pole
For more information on the Spillway go to:

And for some great photos go to:

1 comment:

  1. Such a tragic event. There are no words to describe all the devestation and ruin. I'm so glad you and Frank are okay.

    Hugs - Marie


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