Resilience is defined by an industry consortium as the ability to prepare and plan for, absorb, recover from, and more successfully adapt to adverse events. One of the more interesting aspects of the discussions around resilience is the concept of recovering after an event. Typically, in the design phase, we aim to ensure the damage due to an event is limited to some prescribed level or that, under normal operations, the building systems will perform in a certain way. What is not generally considered is the time or cost of recovery. Since designing to have no damage under any conditions is not realistic, to have true resilience in a community, the buildings and infrastructure must be designed to return to functionality for a reasonable cost and within a specified time frame.
Before and after Hurricane Katrina, New Orleans serves as an interesting example. The population of the “Big Easy” in 2000 was 484,674. That dropped by more than 50% in the immediate aftermath of the 2005 hurricane, and, even now, the population has only recovered to about 80% (391,495) of its previous high. A closer look at the data shows the most vulnerable members of the community are also the least likely to have returned. The infrastructure, including homes, offices, industry, etc., was so severely damaged that repair and recovery took an exceedingly long time. During that time, many of those who relocated intended to return, though, once they put down new roots, they weren't in a position or were unwilling to return once the recovery was substantially complete.