Today my son flooded the bathroom. He's only 4, these things happen. By chance I walked down to the basement and I heard the sound of drip drip drip on plastic coming from the computer storage room. When I entered the room I saw water raining from the ceiling onto a section of my vintage computers...AGGH! That's right, it was *raining* on my IBM PCs, XTs, a 5155, AT, motherboards, IBM clones, portables, laptops, docs, software etc...
but don't worry.
Everything is stored on shelves one inch off the ground in water proof covers or bags, even the boxed stuff.
Result - Nothing damaged! The water bounced harmlessly off the covers to the floor and was relatively easy to clean up. (using a mop to fill a bucket of water plus about 20 rags and a roll of paper towels).
I asked my son..."what lesson did you learn?" He said, "Don't leave the water running in the bathroom" I said, "No. Always cover vintage computer gear to protect against dust and water damage."
NOTE: Use covers, but you also have to allow electronics to "breathe" to prevent mold, and that's why UV light and humidity control are also important. Depends where you live.