Levees by themselves cannot save New Orleans
Building bigger, stronger levees in New Orleans will not be enough to save the US city from another Hurricane Katrina, a report has said…
The report said the authorities should consider raising the level of buildings and even abandoning flood-prone areas…
New Orleans has about 563 km (350 miles) of barriers, levees and other structures intended to protect the city. But in August 2005, large sections of this system failed and much of the city was inundated by the storm surges brought by Katrina.
The report, from the National Academy of Engineering (NAE) and the National Research Council (NRC), said the disaster had exposed the “many weaknesses in the hurricane protection and preparedness systems” for New Orleans and surrounding areas. It said there had been “undue optimism” about the ability of the protection systems to withstand the impact of a storm on the scale of Katrina.
The report said improvements made to the flood protection system since Katrina had “reduced some vulnerabilities”. But, it said that “the risks of inundation and flooding never can be fully eliminated by protective structures, no matter how large or sturdy those structures may be”.
The authors advised that as there can be no absolute protection against storm surges and flooding, the authorities should consider encouraging people to move away from areas at risk. Where this is not possible, “significant improvements in flood-proofing measures will be essential”.
This would include raising the standard height for ground floors of properties, strengthening critical infrastructure such as power and telecommunications and improving evacuation plans.
Seems pretty reasonable to me. Not that my opinion is worth a whole hill of beans. I haven’t lived there in decades and folks whose roots are deep and timed into the city ain’t ever paying much attention to outsiders.
TIt was important to New Orleanians that the Science Panel’s report agreed with IPET findings that the outfall canal floodwalls fell down long before even being overtopped because of engineering mistakes made by the US Army Corps of Engineers. Although the cause is still disputed for some of the other 48 breaches, the Science Panel kind of agreed with IPET that most of the rest of the breaches were caused by erosion from storm surge water overtopping those structures.
The report said New Orleans should get a storm surge protection system to protect from a higher storm surge than what is expected during a storm with a 1 in a 100 chance of hitting in any given year, as is the current plan.
The most important recommendation was that the US Army Corps of Engineers reform to the extent that they would at least accept some small form of oversight from local government engineers, like the ability to review Corp designs of our flood control structures.
Regarding the report’s elevation recommendations and smaller footprint idea. Isn’t it irrelevant for them to say what we should have done? Families that were flood victims only had one shot at recovery. The Road Home Program is almost finished. Moronically, RHP is giving out elevation money last. Who could afford to wait this long? We already rebuilt. We did the best we could with what we had and built smaller, stronger and above the flood line.
The only thing worse than outsiders are expert outsiders.
CrescentCityRay
April 26, 2009 at 3:17 pm