I live on the gulf coast and consider natural diasters (hurricanes) and DR recovery plans to be a way of life. My employer has a diesel generator that is capable of supplying our facility with uninterrupted power for approximately 1 month. I personally think that this may be a bit of overkill because in the event of a disaster of this proportion, most of us will likely have issues (loss of life or property) that would at least temporarily have a higher priority than work; and the utilities would likely be restored by the time that we would resume normal operations.

Two of the most important things that I've learned from my past experiences with natural disasters are: 1) Maintain a solid communications plan/infrastructure including a listing of contact information for all critical employees 2) If you decide to evacuate, you may encounter difficulty when attempting to return due to fuel shortages, debris blocking the roads, traffic and curfews.

My brother works for a call center and whenever the area is threatened by a hurricane, they fly their critical support staff and their families to St. Louis and establish a temporary call center there. They also provide meals and plan fun activities for the families, and have a team that stays behind in order to inspect these employees homes for damage and if necessary perform repairs with building materials that are staged in tractor trailers.

The important thing is to have a plan, critique your plan and when practical, periodically test your plan.