I currently weep with water well water and I would like to have a backup is case I loose power. I’m thinking of tying city water into the weep system using a pressure regulator set at say 10 psi. As long as the well keeps the pressure above 20 psi the city water would not come in play. If the well goes down and the pressure drops to 0, the city water would pressurize the system to 10 psi. Would this work? Would the pressure from the well keep the city water from flowing?