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| Draining New Orleans Could Take a Month |
| 2005-09-03 |
| New Orleans could be facing a month or more before all the flood waters from Hurricane Katrina and ruptured levees can be pumped out. Lowering the water level a foot per day was called an optimistic estimate on Friday, depending on how much of the pumping capacity can be restored and whether any more storms complicate the work. This is the peak of hurricane season and more storms could easily develop. There are six pumping stations in the city and the Army Corps of Engineers could bring in auxiliary pumps. Contamination by oil, chemicals and sewage also complicates the effort. Removing the water would be slowed if it has to be treated before it can be discharged, though it might be possible to get some type of dispensation so it can be pumped quickly into the Mississippi River and Lake Pontchartrain. In addition to pumps, the engineers are working on a plan to make new breaches in the levees _ from hundreds of feet wide to 3,000 feet _ in areas where gravity can help move water out of the city. Lt. Gen. Carl Strock, commander of the Army Corps of Engineers, said the water level in the city has stabilized, and repairs to breaches in two levees are progressing. He also said workers are clearing, surveying and putting in navigational buoys and lights along the coastal channels in an effort to get the ports reopened. Responding to criticism that the federal response has been slow and inadequate, Strock said the destruction of communications lines and transportation routes made it very difficult to determine exactly where help was needed and to get workers and supplies there. "Our biggest problem is communications," he said, noting that cellular phone towers were all knocked out, making it nearly impossible for citizens in need to call for help. "We have to know where to drop (supplies) and what to drop." He also said the corps is working on plans to create a city somewhere in the area to accommodate about 50,000 people _ similar to what was done in the aftermath of Hurricane Andrew in Florida. |
| Posted by:trailing wife |
| #11 Where rail lines pass thru is called a sandbag gap, if it's just a couple of feet high, that can be filled by sandbags. I designed a levee gap 11 feet high, in K.C., called a stoplog gap, that required closing the (3) rail line(s), placing aluminum "stoplogs" across the tracks and pumping out the leakage. But if the pumps fail..... But when the levee is overtopped, by waves or a storm surge, it's all over but the shoutin'. Levees can also be breached by water pressure under the levee, called sand boils, where the pressure causes (sort of) quicksand on the dry side. If not treated promptly, you also get levee failure. Erosion is a bitch. But engineering is SO much more boring than news! |
| Posted by: Bobby 2005-09-03 22:31 |
| #10 Corruption. Just like the big dig. The problem with one party states. |
| Posted by: Mrs. Davis 2005-09-03 21:18 |
| #9 The drainage system predates the canal's current position. It was originally a gravity drainage system. Then levees were built and additional land drained to a pumping station at the head of the canal. Then the levees were raised and additional pumping stations added to dump into the canal. Curiously, a very recent upgrade of the canal levees made it supposedly the most secure part of the lake system. And it was a concrete storm wall on top rather than soil like most. I don't know why it failed, but I should think an investigation is in order concerning the quality of the concrete work and possible corruption. The idea of a storm gate at the mouth of the canal is sound. There is such a system at the mouth of the harbor/'river' in Providence, RI. We have storm gates through the levees in New Orleans at various places where rail lines pass through. Hindsight. |
| Posted by: Glenmore 2005-09-03 19:14 |
| #8 I am speaking from ignorance here so maybe a civil engineer can educate me. The news reports I have seen describe two concrete levee breaches in a canal used to pump water from New Orleans into Lake Pontchartrain. My question is why isn't there a gate at the canal-lake junction that could have been closed to prevent the lake from draining into lower elevation New Orleans. That seems like a sensible and cheap precaution to minimize the effects of any canal levee failure. The water in the canal would have only cause minor and localized flooding. |
| Posted by: ed 2005-09-03 17:11 |
| #7 Thanks for the first hand Glenmore |
| Posted by: Mona Gorilla 2005-09-03 16:55 |
| #6 Nuke the site from orbit. It's the only way to be sure. |
| Posted by: Jackal 2005-09-03 14:00 |
| #5 I am evacuated to Baton Rouge. I am watching dozens of helicopters per hour flying into here (LSU) with medical cases to a triage center. There are dozens more per hour running into the BR airport with supplies and personel. Others are now able to base out of Armstrong airport in New Orleans, also engaged in medevac and supply. For several days a number of the big boys were trying to re-build a levee - imagine trying to fill a football stadium with a teaspoon, carried a mile each way. The levee is now patched, sort of, though it will be some time before pumps can be repaired and powered to start getting the water out. The environmental concern about pumping the horribly contaminated water out is legitimate; we have just managed to get the Lake pollution of decades of abuse cleaned up. But some rules will have to be waived unless the city is to remain a hazardous waste dump forever. The trash and debris draining to the pumps is normal, though the amounts of course are not; there are strainers at the intakes that will have to be cleaned more often. It may be feasible to install some kind of oil skimmers to pull the worst of that off for proper disposal, though I am not sure it could function at the fluid volumes necessary to do any good in draining the city. The other chemical and biological contaminants are impossible (in my opinion). Regarding breaching the levees to enhance drainage - natural breaches in the industrial canal levee have been allowing drainage from the downriver side of the canal for several days. Not a whole lot of natural drainage will occur though, since the best that can be done is to get the level back down to sea level, which leaves 10 feet of water in much of the city. Controlled gates (maybe at the pumping stations) rather than breaches, would allow using the tidal swings to let water flow out at low tide, then close as the tide rises. This could lower the level another foot or two in a week or two. |
| Posted by: Glenmore 2005-09-03 10:08 |
| #4 Maybe I'm speaking from hindsight,but why weren't choppers flying search and relief ops.What I mean is flying around,spot a group of people drop off needed supplies(food,h2o,etc.).Mark the location with GPS,and when the bird is empty pick-up/tarnsport who they could.With GPS corord.the ones left behind could have been easly found. |
| Posted by: raptor 2005-09-03 08:50 |
| #3 The pumps usually don't have to deal with debris of all kinds, oil/fluid spills, and tons of human waste in the water prior to Katrina. I think the estimates are way too generous, considering the pumps will have to be stopped, cleaned, fixed, restarted a number of times. |
| Posted by: Ulong Slereque6682 2005-09-03 08:20 |
| #2 Draining New Orleans Could Take a Month How long to drain it of the current scum infestation? |
| Posted by: Bomb-a-rama 2005-09-03 03:02 |
| #1 Or 80 days as one "high ranking expert" has noted... |
| Posted by: Capsu 78 2005-09-03 00:44 |