# The SD on the Mississippi after Baton Rouge **URL:** \ **Category:** Factual Questions\ **Created:** [December 12, 2003, 8:40am UTC](https://boards.straightdope.com/t/the-sd-on-the-mississippi-after-baton-rouge/218558 "2003-12-12T08:40:03Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Markxxx](https://avatars.discourse-cdn.com/v4/letter/m/5daacb/32.png) [@Markxxx](https://boards.straightdope.com/u/Markxxx)\ **Post date:** [December 12, 2003, 8:40am UTC](https://boards.straightdope.com/t/the-sd-on-the-mississippi-after-baton-rouge/218558/1 "2003-12-12T08:40:03Z")
I keep getting in on this show on one of the “Sub-Discovery” channels it says the basically south of Baton Rouge the Mississippi has become a canal. This is due to the fact years and years ago a guy blew up a log jam and it cause part of the Mississippi River to divert to a new river. This new river is a shorter course to the Gulf of Mexico. So if the Army Corps of Engineers hadn’t stepped in and basically made the Mississippi a canal the river would have diverted and left New Orleans and other ports high and dry and miles from the ocean. Is this right? ---
**Author:** ![Ice\_Wolf](https://avatars.discourse-cdn.com/v4/letter/i/dfb087/32.png) [@Ice\_Wolf](https://boards.straightdope.com/u/Ice_Wolf)\ **Post date:** [December 12, 2003, 11:46am UTC](https://boards.straightdope.com/t/the-sd-on-the-mississippi-after-baton-rouge/218558/2 "2003-12-12T11:46:12Z")
You may find your answer on [this page](http://www.tulane.edu/~bfleury/envirobio/enviroweb/FloodControl.htm), **Markxxx**. > [@](#): > > As time progressed, it became increasingly apparent that the Mississippi was diverting more and more of its flow down the Atchafalaya River. In the 1950’s, engineers observed that the Mississippi would soon cease to inhabit its current channel as the mainstream, and instead migrate to the Atchafalaya River Basin. The path by which the Mississippi would migrate was a small stretch of water, named the “Old River”, that connected the Mississippi to the Red River. Old River was formed when Captain Henry Shreve dug a shortcut across the the neck of Turnbull’s Bend in 1831. The Mississippi abandoned its old course and took the shortcut provided by Old River. As a result, the Atchafalaya River received more and more discharge from the Mississippi. Discharge was also increased into the Atchafalaya in 1840, when a 30 mile long log jam was removed from its headwaters by the state of Louisiana. ---
**Author:** ![lisacurl](https://avatars.discourse-cdn.com/v4/letter/l/41988e/32.png) [@lisacurl](https://boards.straightdope.com/u/lisacurl)\ **Post date:** [December 13, 2003, 5:51pm UTC](https://boards.straightdope.com/t/the-sd-on-the-mississippi-after-baton-rouge/218558/3 "2003-12-13T17:51:15Z")
> [@](#): > > \*Originally posted by Markxxx \* > \*\*So if the Army Corps of Engineers hadn’t stepped in and basically made the Mississippi a canal the river would have diverted and left New Orleans and other ports high and dry and miles from the ocean. Is this right? \*\* The short answer is yes. Ice Wolf provided the citations. The US Army Corps of Engineers - New Orleans Division has a [really informative site](http://www.mvn.usace.army.mil/) about what they do presently to control the river and the Gulf in Louisiana. ---
**Author:** ![county](https://avatars.discourse-cdn.com/v4/letter/c/ce7236/32.png) [@county](https://boards.straightdope.com/u/county)\ **Post date:** [December 13, 2003, 7:41pm UTC](https://boards.straightdope.com/t/the-sd-on-the-mississippi-after-baton-rouge/218558/4 "2003-12-13T19:41:51Z")
I didn’t read the links but I assume they explain that the Corps built the “old river control sturcture” that prevents the Mississippi from changing it’s course. As far North as Baton Rouge the Mississippi is considered a “ship channel” and accomadates up to 40 foot (may be off a few feet) drafts. Below New Orleans you have the “passes” which are sorta like islands between the river and the Gulf. No responsibility for any eerrors in this post but I believe it to be fairly accurate. The story of the Corps and the Mississippi River and the federal government is fascinating. ---
**Author:** ![ElvisL1ves](https://avatars.discourse-cdn.com/v4/letter/e/5daacb/32.png) [@ElvisL1ves](https://boards.straightdope.com/u/ElvisL1ves)\ **Post date:** [December 13, 2003, 10:33pm UTC](https://boards.straightdope.com/t/the-sd-on-the-mississippi-after-baton-rouge/218558/5 "2003-12-13T22:33:02Z")
The topic is explained in fascinating depth in a chapter of John McPhee’s _The Control of Nature_. I’d recommend anything he writes. As he explains it: The Mississippi historically meanders, with the outlet having diverted periodically over pretty much all of what’s now Lousiana. As silt piles up, other ground becomes lower and the river moves. It has “wanted” to relocate the mainstream to the Atchafalaya for quite some time now, but that has been prevented by the Army Corps of Engineers structure at the Old River. That has kept the river dumping silt further and further offshore uselessly, no longer replenishing the rest of the Delta, and letting the sea encroach further inland along the bayou country as the ground sinks. But, it has kept New Orleans and Baton Rouge open to ship traffic and has protected various economic interests. It’s a little scary to be standing in Jackson Square in New Orleans, looking toward the river and seeing a levee where there used to be docks, but having to look _up_ to see the ships go by. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [December 14, 2003, 6:04am UTC](https://boards.straightdope.com/t/the-sd-on-the-mississippi-after-baton-rouge/218558/6 "2003-12-14T06:04:24Z")
> [@](#): > > \*Originally posted by Markxxx \* > it says the basically south of Baton Rouge the Mississippi has become a canal. A sort of “climbing” canal. To keep the Mississippi in its course, you have to deal with the billions of tons of sediment it brings - some combination of dredging out the river bed and building up the levees. It’s a lot of work, and costs a lot of money. From a geological perspective, the Mississippi should already have been captured by the Atchafalaya, and soon will be. In human terms, you can argue at length about just when “soon” will be. I second Elvis’s recommendations of book and author - first rate. ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [December 14, 2003, 10:21pm UTC](https://boards.straightdope.com/t/the-sd-on-the-mississippi-after-baton-rouge/218558/7 "2003-12-14T22:21:20Z")
I’m going out on a limb, here, not at all sure of this: Wasn’t there a bridge built by order of Huey Long that had the effect of restricting shipping upstream of the bridge? Is it still there? ---
**Author:** ![Opus1](https://avatars.discourse-cdn.com/v4/letter/o/858c86/32.png) [@Opus1](https://boards.straightdope.com/u/Opus1)\ **Post date:** [December 15, 2003, 3:08am UTC](https://boards.straightdope.com/t/the-sd-on-the-mississippi-after-baton-rouge/218558/8 "2003-12-15T03:08:27Z")
For the fiction minded, one of Clive Cussler’s potboilers has as its central plot the arch-villain building a giant port well above the waterline, and then plotting to divert the course of the Mississippi so that his port is the only useable one. Can’t recall the title right now–all of Cussler’s books tend to blur together after a while.