There are many different devices however what you should look for old style
with micro switch
Electronic devices are nice but expansive and sophisticated, however any you
use plumbing will be needed.
Try Liquid flow switch from United Refrigeration (URI.com) #FS4-3 $196.00 in
old catalog.

"Pavel314" wrote in message
...

I was down in the basement watering the mushrooms this evening and noticed
that the water pressure (we're on a well) was a bit low. I asked my wife if
she'd left the sprinkler on the garden and she had, so she went out and
turned it off.

I wondered if there was some sort of device that would detect water flowing
from the outside faucet and light a warning light in the house if the water
were left on. Maybe something that fits onto the faucet with the hose
connecting to the detector gizmo. Flowing water would lower the pressure in
the line and flip a switch to turn on the light.

Has anyone heard of such a thing?

Paul