This is awesome. I have a basement area where there is a sump pump running. There have been a couple of times when the rain has been really bad that the pump runs pretty much non stop. I have often wondered what would happen if it just couldn't keep up and the water filled the room. This would be really handy for if something like that happened at night and I needed an alert about what was going on downstairs. I can also see where it would be beneficial in other areas.
I used to have a server room with a water pump for the air conditioning unit. One time the pump stopped working and the reservoir filled up and water got all over my server room. Luckily nothing was damaged, but it could have been really bad I think. This would have been a great tool when that happened to alert us sooner.