Emergency Water Turn-Off?

[Prof Reid <reid@xxxxxxxxxxx>]

Anyone made their own emergency water-turn-off
system?  Like a WaterCop or WaterBug?
Something like a ball valve with an attached
drive wheel and motor to turn the water off.

Also have you tried to get water flow information
from acoustic transducers on water pipes?  I can
"hear" the water flowing inside a pipe with a
stethoscope, but I wonder if I can get quantitative
enough flow information from a strapped-on "mic".

I'd like to use the HA computer, multiple-acoustic sensors,
and an smart algorithm to watch for the acoustic patterns
that could uncover a running toilet (or other undesirable water flows),
and turn the water off.  This flow monitoring, as opposed to the usual
alternative of looking for undesirable water accumulations.

Sound possible, or have you done it?

Thanks,

Dick