Bung: I think blaming earthquakes is just one of those easy things to say. My neighbour had leak from his pipe in the grass berm just after Chorus had been through burying fibre. Rather than wait I dug down to see what had happened and found the toby had about 500mm of copper before a joint to a type of polybutyline pipe normally used inside. The grey poly pipe had a pinhole split just after the compression ring. The plumber that fixed it by cutting out the split section and adding a short piece said that normally that type of pipe was ok so long as it wasn't exposed to UV. The pipe is much thinner than the blue type normally used.
Your pipe may be copper then joint onto something else close to the toby. Can you see what type of pipe arrives at the house? If it is a joint failure close to the toby you may end up with a cut out big enough to expose it. If and when metering ever arrives you'd need a bigger toby box anyway.
The council guy is the one who suggested earthquakes. Doesn't really matter the cause.
We have no idea where the pipe goes into the house. The council plans show where waste water goes, but not water pipes. Access under the house on the side it comes in is very limited, and I have a shoulder injury that would prevent me going under there to poke around. Once we get the council letter we'll come up with a plan, which will probably start with a second opinion on if there's a leak, then locating the leak, then looking at the options to address. The fix could be fixing the pipe, replacing the pipe, or running a whole new pipe.
The toby box is embedded in a concrete driveway. There's no way you could get a water meter in there easily.