Most irrigation systems have an isolation (shut-off) valve. This is most likely housed in a box with a green lid near the SA Water meter, or next to/inside the box that houses the solenoids.
We will attend as soon as we can and, at least, cap off the system so that you can still shower etc.
If we cannot locate an isolation valve it would be wise to install one, complete with a Back-flow Prevention Valve (now required by law).
Sometimes due to power spikes or outages automatic controllers can 'glitch'. This can manifest as a blank display or even a jumbled looking display.
Most controllers have a reset buttons for such instances (you'll need to reprogram the controller once you reset). If depressing the button does not make it behave, try this -