Sorry to see this and I moved out of a flood zone 15 years ago, so my pins are safe from rivers now.
But you can get a hell of a lot of damage from a plugged running toilet, or busted pipe, depending on where the games are located. Seems the best place for a lineup is ALWAYS underneath a bathroom.
The plugged running toilet dual point failure happened to me recently.
We were fixing to go kayaking and would have been gone about 6 hours. I was downstairs letting the dogs out, admiring the games when the first drop fell on TZ's glass. It went to hell real quick from there.
Somebody had flushed the toilet upstairs and it completely filled the bathroom floor, and then came down all over the place in the basement arcade. I managed to pull some games out from under the waterfall and had materials handy to cover the ones I couldn't move. It's good to be in the process of insulating your basement walls with 4x8 sheets of extruded foam. They make excellent watersheds in a pinch. In the end, miraculously I suffered no damages.
Had I been the one to flush that toilet and we had been out the door, I would have no games today, not a one.
So if anybody has any ideas on how to prevent death from above, I'm all ears.