Once the Dike and fixed and the water is pumped out. A major decision needs to be made.
How do we rebuild the City?
I see several choices and I am sure that many more can be added by other Dopers.
Fix Dikes and rebuild city as was. (Bad idea)
Abandon City. (Bad idea)
Raise entire level of city by 6-10 feet, similar to what Seattle did but on a grand scale. Greatly reduces risk of flooding. (Expensive)
Build a much more elaborate dike system that segments the city into compartments and reduces catastrophic events. Reinforce the outer dikes. (I think Expensive but affordable but doesn’t solve all the problems)
What other ideas are there?
What are the pros and cons of my ideas?
What would the cost be?
What am I forgetting?
I have placed this in IMHO in hopes of a polite, hopefully technical discussion.
First of all, New Orleans doesn’t have a lot of dikes, it is a haven for gay males though. What we are dealing with is a problem with the levees. The Army Corps of Engineers has been working on this problem for years. It is just that nobody paid enough attention to pay for the solution until now. Our resident engineering expert, Una Persson, has outlined a workable solution in this thread.. The summary is that New Orleans will be rebuilt with a much stronger levee system. Ideas about relocating the people and the city are idiotic at best. New Orleans is the largest point in the country, important to domestic oil production, and unique historically and culturally. Relocating the people of the city would cost many times what it would cost to rebuild the city in place with a bigger levee system.
When it’s fixed, a line needs to be painted near all the drinking establishments showing what height the high water mark reached so we can all pint to it and reminisce.
Hmmm… that “point” typo seems more appropriate and will be left uncorrected.
I am reposting what **Una Persson ** had in the other thread. It looks like a very sound concept.
Please forgive the “Dikes”. I was thinking about how Netherlands have redundant Dikes and typed dikes instead of Levees.
Here’s what I wrote this morning in another thread about the best quality levee in the New Orleans area (which my parents live near, thank Og):
This kind of levee needs to be built following the plan Una describes above. She mentions raising the levees 20 meters (65 feet, give or take). My layman’s opinion is that 65 feet isn’t necessary – an extra 30 feet should cut it.
But as rightly Una points out, the levee needs to be consistent in size and quality throughout the entire metro area.
Lastly, there is one point on the Mississippi River that needs special attention – the hairpin turn in the river just east of the French Quarter, separating New Orleans’ Central Business District from Algiers. The levees there have been breached twice in the last 40 years, flooding out the Ninth Ward and upper St Bernard Parish each time. With the turn in the river there, storm surge pools up, and puts extra pressure on the levee. Una’s 65-foot-added levee would fit the bill in this area.
Since the city system is already broken at the moment, there is an oppurtunity, IMHO, for other solutions besides ‘abandon’, ‘raise city of existing design’, or ‘rebuild city of existing design inside larger levees’.
As I mentioned in another thread, perhaps the levees could remain open, and the water could be left to seek a new level and balance, restoring flow across the delta wetlands, and lowering the level of the river next to the city. This might include the flow of the river into the Atchafalaya as well.
Once the new patterns of the water are known, a new New Orleans, including port, rail, road, and industry, could be built on pilings and barges and raised islands above the new level of the waters. Much smaller levees could be placed around historical districts and specific landmarks, if these can’t be raised to the new level.
I certainly don’t think New Orleans needs to be abandoned permanently… but it does need to be redesigned before it is rebuilt.
The Extra large Levees are great, should the city also have some isolating levees built throughout? This would be similar to the concept of compartmentalization on Navy Ships.
This would prevent an 80% flooding like Katrina caused. I guess I am trying to err on the side of caution and it may not be worth the extra cost and the need to put huge dividing walls between sections of the city.
It would require many large overpasses to travel from section to section and would cause additional traffic headaches.
Heck we’ve been sending millions of tons of top soil down the mississippi for a long long time.
I wouldn’t think it would take too pump that hole full.
I don’t want to dismiss your idea. As an Environmentalist it rings true as an excellent idea. But the City of New Orleans is the Tourist capital of Louisiana where tourism is it #1 industry. The Health & welfare of the state requires the rebuild of New Orleans as fast as possible. What you’re proposing would take years.
I think your proposal is a sound approach, but politically impossible.
The city is going to continue to sink, from all that I’ve read. Any plan has to take that into account.
Levees and pumps are fallible, as this event has shown. Had Katrina smacked head-on into New Orleans, it would have been worse. Imagine the current situation, but with hurricane-level winds preventing any escape or rescue efforts.
Building higher sounds ludicrously expensive, but I’ll bet that’s what gets done. Being on higher ground is the only safe hedge against future flooding. Unless you want to abandon the city outright and build a new city with its functions elsewhere (something civilizations have done in the past), people are going to demand greater security. Buildings on stilts and on imported ground are the way to do this. (It wouldn’t really be on stilts – but they’d be built on pilings driven deep into the ground, with nothing of importance until you got to above the flood-water elevation, plus a safety margin).
People don’t want to abandon a city, especially today. And they have too manty historical and cultural links to New Orleans as it was.
It’s not as if something like this hasn’t been done before – look at Underground Seattle. They had to build the lower city up higher to avoid the drainage and sewage problems. They could have just abandoned the lower city altogether, but they didn’t. They simply made the ground floor the basement, and built up.
It’s not going to be cheap, and it’s going to take a lot of time. ut nobody’s going to be building in a flooded-out plain anyway. They’re going to have to either fix the levees and pump out a gazillion gallons of water, or start importing landfill now.
Another question I have about the rebuilding of New Orleans is will it still be the same New Orleans many of us love so much? Has most of what makes it special been lost? Will you still get that same feeling when it is finally rebuilt and its time to return and visit them and help the economy out?
Those who say that N.O.should be abandoned are crazy. Why on earth would you do that? There aren’t many cities in America that are as different as N.O. Now if this were to happen to say Atlanta or Orlando (two cities I don’t like) I’d say no big deal. It’s easy to rebuild trac housing and shopping malls, but with N.O. it’s a cultural thing that has been lost. I doubt it will ever be the same.
Okay, all this talk of building levees up an extra 5 or 10 or 20 meters ignores the weak points that washed out this week: the canals. There are a number of major canals that don’t have adequate levees. This time, it was the 17th Street Canal and the Industrial Canal on the 9th Ward/St. Bernard line that gave, not the main levees on the river or lake.
They also need to take into account the “backwash” on Lake Pontchartrain after it overfills, as happened this week. A better analysis of the pressure points – such as the bend at Algiers Point – and extra strengthening there would go a long way towards solving the problems.
The Canal Levee being built up could be linked up with new Levees being added for isolation/containment of floods. As a local would you consider this better or worse than trying to raise all on NO up to Metarie’s Height.
