Think this through with me

[james_davis_nicoll]

A washer in the bathroom tap is shot and the tap has suddenly a substantial flow. I'd rather not waste water for the time it takes a plumber to fix the problem and so I've shut off the water in the basement.

Is there some horrible failure mode I am overlooking, some obvious way turning the water off will lead to a calamity? I've filled the cats' water dish and their brita.

[Update: we have the sound of silence from upstairs]