To check for a water leak, read your water meter and write down or take a photo of the reading (including the red numbers, which indicate litres).
Wait at least one hour before reading your meter again, remember not to use any water, even to flush the toilet during this time.
If the reading has changed, you may have a water leak. Please contact a licensed plumber to investigate.
For safety reasons never leave a water meter box that is open, unattended.