I live in an area that has a chance of flooding as well, however I don't quite have the ability to move anywhere that doesn't have potential flooding issues. Truly the best practices are
Having appropriate home owner's / Renter's insurance
Backing up data offsite (I sprang for a synology to keep at my in-laws house (several towns away) and rsync on a nightly basis)
being smart about placement of electrical equipment, nothing directly on the floor, towers sit on top of the desk, Power strip mounted a few feet up from the floor on the wall.
You can do other improvements to your home to help mitigate flood damage, but everything is situational.
Hope this helps