# Umm.. if New Orleans is "in a bowl" that water's not going to just drain away, is it? **URL:** \ **Category:** Factual Questions\ **Created:** [September 5, 2005, 3:28am UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154 "2005-09-05T03:28:32Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [September 5, 2005, 3:28am UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/1 "2005-09-05T03:28:32Z")
I’ve kind of been thinking/expecting in the back of my mind that the New Orleans flooding will subside and drain away now that he storm’s gone, like it usually does in most locales after the storm is over. However, it just occurred to me (I’m Captain Obvious) that that New Orleans waters not going to go _anywhere_ if NO is sitting in flooded bowl level with, or below, the outside water level, and that NO will stay flooded until the levees are repaired, and the the city will have to be pumped out which is going to take months. NO is going o be under water for quite some time. Is that correct? ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [September 5, 2005, 3:32am UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/2 "2005-09-05T03:32:44Z")
That’s my understanding, yeah. ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [September 5, 2005, 3:42am UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/3 "2005-09-05T03:42:59Z")
You are correct, sir! They are alredy preparing to actually remove _more_ of the levee where the original breech occurred (once the lake has dropped) to get some of the water out more quickly, then patch up the levees and begin pumping. ---
**Author:** ![Zebra](https://avatars.discourse-cdn.com/v4/letter/z/c0e974/32.png) [@Zebra](https://boards.straightdope.com/u/Zebra)\ **Post date:** [September 5, 2005, 3:46am UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/4 "2005-09-05T03:46:40Z")
The Army Corp of Engineers guy said at a press conference (yesterday?) that once the levee is fixed they have to fix the pumps and then it will be 35 to 90 days to de-water the city. Really should have keep those levees built up strong. ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [September 5, 2005, 3:46am UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/5 "2005-09-05T03:46:45Z")
[Pumping water out of New Orleans could take a month (USA Today)](http://www.usatoday.com/news/nation/2005-09-02-floods-neworleans_x.htm) … ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [September 5, 2005, 3:50am UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/6 "2005-09-05T03:50:43Z")
The water level in lake Ponchartrain was raised by the hurricane. The levees failed, and the water level in the city reached equilibrium with that raised lake level. The lake _is_ draining to its normal pool size. As long as they don’t block the holes in the levees too soon, that will also lower the water level in the city. Since the city is lower than the normal lake level, they can’t get rid of _all_ the water that way, but even a foot or two represents many thousands of acre feet that won’t have to be pumped out. ---
**Author:** ![Ruby](https://avatars.discourse-cdn.com/v4/letter/r/13edae/32.png) [@Ruby](https://boards.straightdope.com/u/Ruby)\ **Post date:** [September 5, 2005, 3:52am UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/7 "2005-09-05T03:52:42Z")
Where do they pump the water to? ---
**Author:** ![The\_Flying\_Dutchman](https://avatars.discourse-cdn.com/v4/letter/t/9fc348/32.png) [@The\_Flying\_Dutchman](https://boards.straightdope.com/u/The_Flying_Dutchman)\ **Post date:** [September 5, 2005, 3:55am UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/8 "2005-09-05T03:55:13Z")
> [@tomndebb](#): > > You are correct, sir! > > They are alredy preparing to actually remove _more_ of the levee where the original breech occurred (once the lake has dropped) to get some of the water out more quickly, then patch up the levees and begin pumping. Could that have something to do with tidal action? I understand that the lake level at its highest is actually even with the gulf. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [September 5, 2005, 4:11am UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/9 "2005-09-05T04:11:29Z")
> [@Ruby](#): > > Where do they pump the water to? Anywhere outside the levees, either the lake or the river. ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [September 5, 2005, 4:16am UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/10 "2005-09-05T04:16:23Z")
> [@](#): > > Could that have something to do with tidal action? It has more to do with the point **Squink** made. Ponchartrain rose above its normal levels with the hurricane rains (and some storm surge) and is slowly returning to its normal levels, out through Lake Borgne to the Caribbean. As it recedes, breeched levees in N.O can let the"top layer" of water out to drain east from the lake into the Caribbean. Once equilibrium has been reached, they need to shore up the levee (to prevent the lake from returning) and begin pumping. The water will be pumped into the (now lower) lake, into the Mississippi River, and into the bayous south and east of the city. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [September 5, 2005, 4:17am UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/11 "2005-09-05T04:17:00Z")
> [@Ruby](#): > > Where do they pump the water to? Lake Ponchartrain, the bayous to the south of the city, and (according to Tom’s link) the Mississippi river. Here’s a nice overview of the [Geography of New Orleans](http://www.southbear.com/New_Orleans/Geography.html). Satellite shots show the disconnect between lake Ponchartrain and the gulf and the canal system. Unfortunately, the pumping stations aren’t pinpointed; likely one of those “lessons of 9/11” things. ---
**Author:** ![Marley23](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Marley23](https://boards.straightdope.com/u/Marley23)\ **Post date:** [September 5, 2005, 4:18am UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/12 "2005-09-05T04:18:16Z")
It’s still the peak of hurricane season - here’s hoping no other hurricanes come near them. ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [September 5, 2005, 4:33am UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/13 "2005-09-05T04:33:38Z")
[This map of the Northeast section of the city](http://www.mvn.usace.army.mil/pao/response/NOEast.asp) shows the pumping stations marked by lower case letters, a through g. ---
**Author:** ![levdrakon](https://avatars.discourse-cdn.com/v4/letter/l/49beb7/32.png) [@levdrakon](https://boards.straightdope.com/u/levdrakon)\ **Post date:** [September 5, 2005, 4:46am UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/14 "2005-09-05T04:46:30Z")
> [@Squink](#): > > > [@Ruby](#): > > > > Where do they pump the water to? > > Lake Ponchartrain, the bayous to the south of the city, and (according to Tom’s link) the Mississippi river. Is that where all the toxic pollution goes, too? Not being an ass, just wondering where all the pollution goes. ---
**Author:** ![Diceman](https://avatars.discourse-cdn.com/v4/letter/d/22d042/32.png) [@Diceman](https://boards.straightdope.com/u/Diceman)\ **Post date:** [September 5, 2005, 1:42pm UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/15 "2005-09-05T13:42:38Z")
The pollution will probably just get sucked out with the water. If they had to filter out all the crud, then the de-watering process would take years, not months. ---
**Author:** ![Tapioca\_Dextrin](https://avatars.discourse-cdn.com/v4/letter/t/3d9bf3/32.png) [@Tapioca\_Dextrin](https://boards.straightdope.com/u/Tapioca_Dextrin)\ **Post date:** [September 5, 2005, 1:47pm UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/16 "2005-09-05T13:47:14Z")
> [@tomndebb](#): > > As it recedes, breeched levees in N.O can let the"top layer" of water out to drain east from the lake into the Caribbean. That’s one long drain 😃 ---
**Author:** ![tangtbdoa](https://avatars.discourse-cdn.com/v4/letter/t/e5b9ba/32.png) [@tangtbdoa](https://boards.straightdope.com/u/tangtbdoa)\ **Post date:** [September 5, 2005, 2:17pm UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/17 "2005-09-05T14:17:25Z")
Squink… thanks for posting that link to N.O. geography. Very enlightening. I was watching CSPAN a couple of days ago and the Army Corps of Engineer General was explaining that when they built this levee system they designed it to handle up to a category 3 hurricane. They did the risk analysis studies and found that there was less than a .05% chance that within 300 years there would be a category 4or5 storm to hit N.O. In other words they felt that they had a 99.5% level of safety to protect against a cat 4 or 5 hurricane. In light of what I learned about the geology of the area (the irony that the current solution may well be contributing to the failure of the system since the river is no longer depositing silt along the riverbanks) it seems that we really need to rethink the next course of action when the city gets back on it’s feet. Man and his engineering feats are wonderful and amazing but there are times when we need to “fall back” and regroup with a better game plan. ---
**Author:** ![Zsofia](https://avatars.discourse-cdn.com/v4/letter/z/7bcc69/32.png) [@Zsofia](https://boards.straightdope.com/u/Zsofia)\ **Post date:** [September 5, 2005, 7:31pm UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/18 "2005-09-05T19:31:55Z")
My understanding is that even before the hurricane, every single drop of rain that fell on the city that didn’t evaporate had to be pumped out. ---
**Author:** ![dre2xl](https://avatars.discourse-cdn.com/v4/letter/d/34f0e0/32.png) [@dre2xl](https://boards.straightdope.com/u/dre2xl)\ **Post date:** [September 5, 2005, 8:06pm UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/19 "2005-09-05T20:06:08Z")
If the toxic water is just drained back into surrounding nature, wouldn’t that be counterproductive–it would seep into the natural water supply and render the area uninhabitable for months anyway… ?? (Unless you’re willing to take a tetanus shot every time you scrape your knee while playing outside & putting a little bleach in everything you drink, that is…) ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [September 5, 2005, 8:25pm UTC](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154/20 "2005-09-05T20:25:37Z")
> [@](#): > > If the toxic water is just drained back into surrounding nature, wouldn’t that be counterproductive–it would seep into the natural water supply and render the area uninhabitable for months anyway… ?? Remember, the city is at the mouth of the largest river system on the continent. There’s a lot of fresh water that goes through N’Awleans. Anything they dump into the river will quickly be washed out the Gulf, which they wouldn’t be drinking anyway, and more fresh water will be pouring into the city’s supply from everywhere from Pittsburgh to Yellowstone. Mind you, New Orleans does also get the pollution from everyone upstream of them, which is darn near everyone. But they’ve always gotten that, even at the best of times. I presume that the city’s infrastructure and citizens are already capable of handling that expected level of pollution. [Next page](https://boards.straightdope.com/t/umm-if-new-orleans-is-in-a-bowl-that-waters-not-going-to-just-drain-away-is-it/320154.md?page=2)