I don't leave the property for long, without shutting off the pump. All I would get is what's in the tank. I have on occassion wired in a contactor, so when people's alarms are armed (away) the pump is shut off. The contactor is something that is on my "LIST" of things to do.
If you have a water sensor, the question always is, where best to put it.
I had customers where the faucet connection on the third floor broke, in a house that wasn't visited for months! That water would have been a while getting to a detector in the basement. It might have been better if the house had burned to the ground!