Check For Leaks
Leaks are often the culprit for unexplained increased consumption, and toilet leaks are the most common. A single running toilet can waste thousands of gallons of water in a two month billing period. Repairing toilet leaks are usually easy and inexpensive to repair.
To check for a leak, remove the top of the tank behind the bowl and put three or four drops of food colouring in the tank water. Don't flush the toilet for an hour or more if possible. Then check the water in the bowl, if the bowl water has been coloured with the food colouring, you have a leak. This type of leak is usually easy to eliminate by replacing the flapper assembly. If this does not work, consult your hardware store or plumber.
Check for dripping taps, and fixtures. If you don't find any leaks or drips, the next step is to read your meter. Read your meter just before to residence is going to be empty for several hours. Upon return, read your meter again. If the meter read has changed, there is a leak after the meter, somewhere in the home. A plumber may be needed.