If you have an in-ground irrigation system, check it each spring before use to make sure it wasn’t damaged by frost or freezing. An irrigation system that has a leak 1/32nd of an inch in diameter (about the thickness of a dime) can waste about 6,300 gallons of water per month. If you need help, hire an irrigation professional certified by a WaterSense labeled program to inspect it for you. These professionals have passed a certification program focused on water efficiency. They will not only help you detect and correct leaks in the system, but also maximize its efficiency.

• The Region of Peel in Ontario has a good overview for how to check for sprinkler system leaks. 
• The Salt River Project in Arizona has good tips on how to determine if you have a pool leak. 

Tip: Don't forget garden hoses! Check your garden hose for leaks at its connection to the spigot. If it leaks while you run your hose, replace the nylon or rubber hose washer and ensure a tight connection to the spigot using pipe tape and a wrench.

For more information, check out the EPA website's 'Fix a Leak Week' article.