A $14 billion upgrade to New Orleans’s flood protection system has been completed, as recommended following Hurricane Katrina in 2005. For the U.S., this is a pretty massive and fast public works project. I haven’t delved into any technical details and am only going on this Scientific American article, but it sounds like it will not provide the level of protection originally envisioned.

The agency’s projection that the system will “no longer provide [required] risk reduction as early as 2023” illustrates the rapidly changing conditions being experienced both globally as sea levels rise faster than expected and locally as erosion wipes out protective barrier islands and marshlands in southeastern Louisiana….

Sea-level rise raises questions about whether the protective system—known officially as the Greater New Orleans Hurricane and Storm Damage Risk Reduction System—should be built to a higher standard.
When Congress approved funding after Katrina, it required the system to protect against a so-called 100-year flood, which has a 1% likelihood of occurring in any year.

That’s a laudable attempt to communicate probability to the public. But if the Army Corps is really using the “100-year flood” as its design standard, and if it’s doing that because Congress prescribed it, and if they did not consider coastal erosion or adequately consider sea level rise, this may be yet another sign the U.S. is slipping behind its peer group of advanced nations. The Dutch are not doing this, they are providing a much higher level of protection to coastal population centers based on the economic value of doing so. I want to believe Congress will do the right thing and protect our coastal population centers when push comes to shove, but I am not encouraged.

Of course, if it protects from a 1-chance-in-50 event rather than a 1-chance-in-100 event, this is not nothing. Each year, and over the course of several decades or a century, your city and personal property either floods or it doesn’t. When it does, you either have practical and financial plans in place to help you bounce back, or you don’t. So good planning, good public works design, good building codes and land use controls, insurance and disaster resilience planning all matter. Some academics, professionals and bureaucrats within the U.S. might be talking about these things, but our political system is certainly not on the cutting edge when it comes to putting them into practice.