The water bill is high. Had all the toilets and faucets checked and fixed. But still the water bill is high.

We have an automatic sprinkler system. And there was a construction done before around the house which might possibly hit the sprinkler system.

Since the yard is divided into several zones by the sprinkler, how will you know if there are leaks in that particular zone?

Is there a way aside from digging all the sprinkler tubes underneath?