I had the samething happen to me at our last house! The sickening part is I had to THROW EVERYTHING AWAY. My entire sewing room including machines! We had HEAVY rains one year and we had 4' of water in our basement. Luckily our homeowners insurance covered everything because everything was a total LOSS!
I would go for the basement and store everything in bins and put a couple of wooden pallets on floor so that your bins will be off the actual floor. Hope this make sense.
Good luck! :)
Liz