Monday, April 14, 2008

Controlling the Mississippi River

I have always been fascinated by rivers. This started when I was a boy in Nebraska, as I spent many summers on the Missouri, Platte, Loop, Cedar, and Niobrara. Since then I've swam in the Nile, Jordan, Euphrates, and the Ganges. Now that I live in New Orleans, the Mississippi River commands my attention and respect. One of the most interesting books I've read is John Barry's Rising Tide, which discusses America's attempts to control the Mississippi and the great flood of 1927. With the large amounts of rain that have fallen in the Great Plains, the Mississippi River's levels in New Orleans are the highest they've been in years. This again shows me how much the United States depends on New Orleans and the Mississippi River, in that you can transport goods from the Gulf of Mexico via water to a huge amount of the country, just as rain in Minnesota, Ohio, Arkansas, and Missouri makes it way down south to us. The recent near record levels of water prompted the Army Corp of Engineers to open the Bonnet Carre spillway, which releases water from the river into Lake Pontchartrain. I took Gilgamesh and Kalypso to see this on Saturday. It's the first time in 10 years they've opened the spillway, which was built right after the flood of 1927. Usually the spillway is swampy, full of wildlife and alligators. With the river water now pouring in and through the land, I've heard that alligators will get pushed into Lake Ponchartrain. I've also heard that many fish will die from pesticides in the river water. Be safe all you Pontchartrain manatees!
P4122555.JPG
Bonnet Carre Spillway, with river water to right being released into spillway towards Lake Pontchartrain to the left.

3 Comments:

Blogger rcs said...

I'm hoping they'll open the New River Control Structure as well. And, as always, I'll flog John MacPhee's The Control Of Nature: Atchafalaya. It should be required reading for everybody who lives near the lower Mississippi.

7:15 PM  
Blogger Ryan said...

Michael, it isn't pesticides that will kill the fish, it is lack of disolved oxygen in the lake that will result from crazy-unabated growth of algae. This algae will grown rampantly because of the fertalizers which midwestern farmers use on their farm lands flows over the land and into the river... and through the now open spillway.

There is an area at the mouth of the river known as the dead zone, because these fertalizers and nutriens cause a seasonal massive algal bloom where the river meets the gulf preventing fish from living there.

rcs, there is no "New River Control Structure." There is something known as the "OLD River Control Structure," and you have even provided a link to ana erial view of a small piece of it. Specifically you show the Auxillary Stucture (by name only, as it is currently the predominate structure used). This is a piece of an overall larger complex known as the Old River Control Structure.

Plus, it IS open. it is always open. By law. From the Congress of the United States of America. At that exactly 30% of the total flow in the Mississipi River reaching the strucutre must gown down the Atchafalaya. No more, no less. by law. Allowing more water to travel down it might start an irreversable chain reaction wherin, the Atchafalaya channel would capture the flow of the Mississippi. Thus, it can't be used as a flood control structure. Anyway, if it were to be used as such, such a massive amount of water would destroy Morgan City, and we don't want that happening for some reason or another. It also just isn't neccessary to use it as a flood control strucure. All of this is covered in the Control of Nature (although in a rather convoluted narative).

More info can be read here.

9:38 AM  
Blogger Ryan said...

Also, this article show how the nutrients can be beneficial in the longer term.

9:47 AM  

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