Scientists working for the U.S. Army Corps of Engineers have taken many of the lessons learned during their exhaustive analysis of the impact of Hurricane Katrina on the New Orleans flood defenses and have created a system for calculating the probability of storm flooding, almost on a lot-by-lot basis, in each drainage basin of the city.
The Corps plans to use the tool to help citizens, planners and policy makers understand the risks present in various locations, and identify areas where improvements to the flood defenses will have the greatest risk-reduction benefits.
Although it is now optimized for New Orleans and storm surge hazards, the same approach could be applied to other locations with different hazard mitigation infrastructure systems. The process scientifically weighs the probability that a hazardous situation will develop, against the reliability of the performance of the protective infrastructure against the load. Ultimately, the process factors in the consequences of failure to develop a quantified measure of risk. If engineers find a way to increase the reliability of the protective system in any given area, the calculated risk to life and property in that location will be driven down.
It is important to take the final step of evaluating the risk-reduction potential of potential projects. In lightly populated areas, decreasing the chances of flooding by improving levees, for instance, may not actually do much to reduce risk, since there are few lives and little improved property at stake. But in a dense urban area, the same investment in improvements could have a dramatic impact on economic health and public safety.