Checking for leaks at your meter.
First you need to turn off all water using appliances and fixtures. Then observe the small leak detection triangle that is located on the dial of your water meter. If this triangle is rotating (even very slightly), there is water leaking.
Checking for toilet leaks
Toilet leaks can be detected by adding a few drops of food coloring to the water in the toilet tank. Leave the food coloring in the tank for at least ten minutes. If colored water appears in the bowl, the toilet is leaking.