# Probability of New Orleans Flooding **URL:** \ **Category:** Factual Questions\ **Created:** [September 15, 2004, 12:31pm UTC](https://boards.straightdope.com/t/probability-of-new-orleans-flooding/264539 "2004-09-15T12:31:34Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![Papermache\_Prince](https://avatars.discourse-cdn.com/v4/letter/p/f05b48/32.png) [@Papermache\_Prince](https://boards.straightdope.com/u/Papermache_Prince)\ **Post date:** [September 15, 2004, 5:42pm UTC](https://boards.straightdope.com/t/probability-of-new-orleans-flooding/264539/21 "2004-09-15T17:42:46Z")
> [@Papermache Prince](#): > > Does anyone know what the evacuation plans are for those without cars? According to this [AP article](http://abcnews.go.com/wire/US/ap20040915_256.html), More information from this [link](http://www.nola.com/newslogs/breakingtp/index.ssf?/mtlogs/nola_Times-Picayune/archives/2004_09.html#033044) > [@](#): > > Curfew set for 2 p.m. in New Orleans > > A citywide curfew will go into effect at 2 p.m. today for all vehicular and pedestrian traffic except for essential personnel, New Orleans Police Superintendent Eddie Compass said at a morning news conference. That’s about the time when tropical storm-force winds will arrive in the city. Compass also announced that he has issued an order forbidding price gouging. > > After 2 p.m., Compass said police will detain people out on the streets. Mayor Ray Nagin said homeless people will be taken to shelters. Nagin also said the city may open several general public shelters, with a decision to be announced by 11 a.m. He said no weapons, pets or household effects would be allowed, and that those who use them should bring their own food,w ater, blankets, pillows, diapers, and medicine, “and nothing else.” > > The Superdome is open for people with special medical needs, city Health Department Director Kevin Stephens said at the briefing. The shelter is only for people who need a steady supply of electricity to stay alive, he said, and they should bring prescriptions, food and personal effects with them. > > A decision on opening shelters for the general public will be made later today, Nagin said. ---
**Author:** ![Pork\_Rind](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pork_rind/32/111_2.png) [@Pork\_Rind](https://boards.straightdope.com/u/Pork_Rind)\ **Post date:** [September 15, 2004, 6:32pm UTC](https://boards.straightdope.com/t/probability-of-new-orleans-flooding/264539/22 "2004-09-15T18:32:22Z")
I read John McPhee’s [The Control of Nature](http://www.amazon.com/exec/obidos/tg/detail/-/0374522596/qid=1095272241/sr=8-1/ref=pd_ka_1/102-8946579-7499344?v=glance&s=books&n=507846) a while back. In that book, McPhee describes the [structures](http://www2.sjsu.edu/faculty/watkins/oldriver.htm) built to prevent the [capture](http://www.loyno.edu/lucec/mrdcontrol.html) of the Mississippi’s flow by the Atchafalaya river. As I recall, it’s speculated that a good walloping from a hurricane could [defeat](http://civilu.ce.utexas.edu/stu/mcbraymc/ce385proposal.html) these dams. Has there been any recent discussion of this now that Ivan may be heading that way? ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [September 15, 2004, 6:39pm UTC](https://boards.straightdope.com/t/probability-of-new-orleans-flooding/264539/23 "2004-09-15T18:39:08Z")
A really interesting description of New Orleans’ drainage situation is found in _The Control of Nature_ by John McPhee. The basic story is as Johnny LA said: Instead of staying (and dumping all its silt) in one course, a river like the Mississippi wants to meander, changing its mouth every 50 - 100 years or so. A vast (and vastly expensive) system of pumps, dikes, levees, etc. has prevented this from happening (though it will certainly come to pass in the next 200 years - and perhaps much sooner). The only way to keep the status quo is to keep increasing the height of the levees that contain the river, as it brings down more silt and the surrounding land slowly sinks. So the river is now well above the level of the city and the potential for catastrophe is obvious. You probably don’t want to be in New Orleans when a major hurricane hits. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [September 15, 2004, 6:42pm UTC](https://boards.straightdope.com/t/probability-of-new-orleans-flooding/264539/24 "2004-09-15T18:42:03Z")
That’s the trouble with preview - when the SDMB is slow, you get scooped by Pork Rind. ---
**Author:** ![Pork\_Rind](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pork_rind/32/111_2.png) [@Pork\_Rind](https://boards.straightdope.com/u/Pork_Rind)\ **Post date:** [September 15, 2004, 7:00pm UTC](https://boards.straightdope.com/t/probability-of-new-orleans-flooding/264539/25 "2004-09-15T19:00:52Z")
> [@Xema](#): > > That’s the trouble with preview - when the SDMB is slow, you get scooped by Pork Rind. Yeah but you posted actual content. I just jammed in a lot of links. That’s the source of my speed. ---
**Author:** ![MaryEFoo](https://avatars.discourse-cdn.com/v4/letter/m/ba8739/32.png) [@MaryEFoo](https://boards.straightdope.com/u/MaryEFoo)\ **Post date:** [September 15, 2004, 11:44pm UTC](https://boards.straightdope.com/t/probability-of-new-orleans-flooding/264539/26 "2004-09-15T23:44:22Z")
Do those pumps work during a power outage? If they have back-up generators, how many hours’ fuel do they have? And it sounds as the authorities don’t have much of a contingency plan for this. Is it a matter of political philosophy, lack of money, or what? This question is due to evidence of minimal shelters (bring your own water?!) and no one laying on evacuation transportation (no busses or trains available to take people to a safer zone). Ivan has over 100 miles radius (double for diameter) and is moving at 9 mph, so that’s about 20 hours of storm for the widest dimension of the storm to pass over one area. Geeze louise, I’d want to be visiting Aunt Minnie in some other state about now. We have earthquakes, they aren’t nuthin. ---
**Author:** ![Chairman\_Pow](https://avatars.discourse-cdn.com/v4/letter/c/838e76/32.png) [@Chairman\_Pow](https://boards.straightdope.com/u/Chairman_Pow)\ **Post date:** [September 16, 2004, 2:28am UTC](https://boards.straightdope.com/t/probability-of-new-orleans-flooding/264539/27 "2004-09-16T02:28:52Z")
> [@bordelond](#): > > New Orleans native checking in. > > New Orleans has minor floods often, and major ones maybe once or twice a decade. The pumping stations do run around the clock in the event of a major flood. Evaporation also takes care of a lot of flood water. Don’t know if you know the answer to these: Where are these pumps pumping from? Just taking the stuff out of the storm drains and putting it…where? Also, how do y’all handle the sewage that will creep up? Everyone just ignore it, or is there a run on pine sol? How’d the less-modern people deal with this sort of stuff? Like the original settlers. I recall from a tour I took when I was there, the biggest fear was actually fire or disease. Were there Indian tribes that lived in the area prior to that? ---
**Author:** ![danceswithcats](https://avatars.discourse-cdn.com/v4/letter/d/9e8a1a/32.png) [@danceswithcats](https://boards.straightdope.com/u/danceswithcats)\ **Post date:** [September 16, 2004, 2:57am UTC](https://boards.straightdope.com/t/probability-of-new-orleans-flooding/264539/28 "2004-09-16T02:57:27Z")
> [@Johnny L.A.](#): > > But you may ask, “If it’s below sea level, why wasn’t it flooded in 1718?” Hell if I know. It was always a swampy area, so maybe it _was_ under water much of the time. I suppose that there was naturally wet and dry periods. Once the levees and canals were built, and later, the pumps added, it was possible to keep it fairly dry most of the time. The levees were built up, and the ones I’ve been on were more than three meters high. > > Another thing to consider is that the path of the river used to change over time – over hundreds of years. The mouth of the river would “wag” east and west as sediments built up in the delta. When the city was built this natural cycle was interrupted. The river “wants” to move, but human structures have prevented it. Eventually, Nature will prevail. The Netherlands have been working on the same issue since the 13th century. The name itself means “the low countries”-IIRC ~40% of the land is below sea level. A system of dams, dikes and canals have been used to drain the land to render it usable, an area exceeding a half million acres. After a 1953 mega-storm, the Oosterschelde barrier project was undertaken: a two mile long movable seawall. The History channel segment on it was one of the more fascinating programs I’ve seen. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [September 17, 2004, 4:38am UTC](https://boards.straightdope.com/t/probability-of-new-orleans-flooding/264539/29 "2004-09-17T04:38:46Z")
> [@](#): > > Where are these pumps pumping from? Just taking the stuff out of the storm drains and putting it…where? Up into the river. > [@](#): > > How’d the less-modern people deal with this sort of stuff? They lived with the floods and the river’s meandering. The indians didn’t have a fixed city to defend, so they decided not to build levees. [Previous page](https://boards.straightdope.com/t/probability-of-new-orleans-flooding/264539.md?page=1)