This report from Risk Management Solutions, Inc. on the Hurricane Katrina flooding in New Orleans is quite good, and shows that, despite suffering four major hurricane-caused floods in the last 100 years, the approach to flood protection in the city is still one of addressing the problem that just occurred, rather than preparing defenses based on expected future risk.
The best part of the report is Section 4, which examines how the Federal Flood Insurance Program is being inundated, in part because it has become a subsidy for flood plain development rather than an insurance program. If you are pressed for time, Section 4 will take only 5 to 8 minutes to read. The next best part is Section 5, which advocates that flood protection planning be based on risk assessments, with development within the flood plain tied to the chance each particular structure has of being flooded.
Some might assume that this is being done, but it is not. Section 5 presents a convincing illustration of the continual re-occurrence of "reactive investment," where defenses are upgraded after a flood to deal with the last flood. Major floods are an infrequent occurrence, but the interval between them is taken as evidence that the flood defenses have solved the problem, and development is allowed in even higher-risk areas, ensuring that the next flood will be even more catastrophic. This complacency also leads the supposedly improved defenses to degrade, endangering not just new development but also the existing property that the defenses were designed to protect.
A good report, but let’s not forget RMS is selling its services — sophisticated computer modeling of risk assessment — in this report. That doesn’t mean what they are saying is untrue, but like any report, it does mean that its conclusions are colored by its point of view.
Hat tip: Mark Geoghegan at blog-re.
CORRECTION: I’ve fixed the spelling of Mark’s name, which I misspelled in my haste to post.