I have a VERY old sprinkler system. It's a Toro hydraulic, not an electric control. The controller has a piece of tubing that goes to each valve in the ground. The controller pushes a plunger to push water to the valve and turn it on or off. I've tried to disconnect this system by turning off what I think is the main valve. Near the house, there is a concrete box with gate valves in it, and near that there is a round cover in the ground with the word "Toro" on it. In that, in the ground, is a gate valve. I turn this gate valve all the way clockwise, and it doesn't do anything different (water still going to the leaky zone valves, and floods the yard). So I capped all the sprinklers in the two zones that were leaking (very old valves), and that was fine. But this week, a cable installer dug a trench, and I suspect he cut the controller tubing, and the sprinklers are leaking again. I''ve capped some more of them, but now I have to dig up the broken control tubing and plug it, hoping this will cure it. For now, till something happens again.
So, my question is, should that Toro gate value turn the system off, or is there something ELSE I've missed to turn it off? This valve turns fine, but the water still flows to the system. And another question: Is there a single point where this system is tapped into the main water system? Should it be close to that main gate valve? I want to kill this sprinkler system for good, and not have to mess with it every time a zone decides to come alive!
Gate valves don't always shut off a hundred percent. If you work your way back to the water meter that supplies the system, you might find a point where you can install a cap or a plug.
Systems like yours are considered more or less a total loss, because the control tubing is not locatable by instruments that can locate control wiring, and the odds are overwhelming that the original system was installed without any backflow protection. By the time the faults are remedied, the time and expense might be better served by starting over.