Hi, Nikki:

Where I live we worry more about forest fires than floods or wind, although this summer we had a couple of microblasts, which tore two of the skylights out of my arena, so I guess we can never say never!

I was at a CDI in Chicago last year and the whole show ran under tornado and lightning warnings.  My Dad was riding his test when there was a huge lightning strike, and the announcer requested that all the riders and spectators return to the barns until further notice, with the exception of the rider in the ring, who had to continue!  Every night there was another tornado warning, and the stabling staff warned us that we might arrive at the venue the next morning and not find our horses in their stalls.  The FEI stabling was in tents, and had a tornado touched down in close proximity all the horses were to be moved to alternative sites.  I'm not clear on how this was going to happen, or what good it might have done, as my understanding of tornadoes is that they're somewhat less than predictable.

I have a friend in Loxahatchee, FL, who went through Katrina.  They kept the horses battened down in their stalls, with extra water buckets hung and lots of hay.  They had to haul water in pickup trucks (apparently garbage cans lined with garbage bags tied off keep the water from slopping around) for nearly 10 days until everything was back up and running.