Do I need a floor drain for the water heater in my townhome?
I am currently running a 1995 rheem gas water heater.  I've flushed it once.  I've never replaced the anode.
I installed a floodsafe water detector shutoff solonoid so that if a leak on the floor occurs the cold water supply is shutoff from the hot water tank.
I have a floor drain which goes to a plastic sump basin with pump that is embedded in the slab.
I put a piece of weatherstripping on the bottom of the interior side of the door so that water won't flood out of the utility room.  My walls are concrete board and the floor is concrete.
I am thinking about replacing mine but should it fail in the meantime it shouldn't be too terrible.
A reasonable fix for you might just be to drill a 4&quot; hole through your slab into the drainage layer below the slab which should be gravel.  Add a floor drain cover and call it a day (unless you live in a high radon area - even then with a gas hwt you are likely pulling enough air out of that room ).  Add the solonoid shut off and choose waterproof materials for that room (turn it into a pseudo shower base) so the water doesn't migrate out of the room and can drain out through the hole you punched in your slab should it fail.