I'm looking for infro on sump pump backup system that uses city water supply and doesn't require battery?

Question:I've recently heard of a system installed by professional plumbers that can back-up my sump pump system that uses my cities water supply and does not require a battery.

Answers:
"Water-powered sump pump back-up systems" use the pressure of city water to pull additional water out of your sump. Of course that means that you're discharging a lot of additional water. Only as an emergency back up.