Most leaks are easy to detect and fix. All you do is check, twist, and replace:
Check for leaks. Look for dripping faucets, showerheads and sprinklers. Check for toilets with silent leaks by putting a few drops of food coloring into the tank, waiting 15 minutes, and seeing if color appears in the bowl before you flush.
Twist and tighten hose and pipe connections. To save water without a noticeable difference in flow in your bathroom, twist on a Water Sense-labeled faucet aerator.
Replace the fixture if necessary. Look for Water Sense-labeled models, which are independently certified to use 20 percent less water and perform as well as or better than standard models.