Why and how is water leaking heavily post-valve irrigation

I get home and water is pouring out under the concrete and flooding a low area in our backyard. I run up to meter, it is spinning, I turn off ball valve to irrigation and it stops. However; the only place I can find water is AFTER the controller valve which is off. No water around it. See picture. How can this leak happen so far past the valve if the valve is closed?? My head is spinning. This is also under concrete and I have no idea how to find the leak! I think squirrels ate through the PVC under the concrete in their run. Please help with advice how to find the leak, where to look, so I have to rip up concrete to fix? Call a plumber? Thanks!

 

You need to call an irrigation company, not a plumber.

If your irrigation system tied to the city water there is pressure at every valve of the sprinkler system. Or at the one valve for a zone index system. From the ball valve to the irrigation valve(s) the pipe broke. Usually a bad glue joint the gave way after many years or tree roots lifted the pipe or ground movement in California. Squirrels do eat PVC and even underground it does get brittle. Most irrigation guys install the thin wall stuff, 160 psi printed on the pipe. I’ve broken many of these by just tapping the pipe with a shovel.