Start with the water meter and the property's irrigation valves. Soggy ground, sinkholes, a meter that moves with the buildings shut off, and an unexplained rise in the bill all point to irrigation piping. Heads, valves and backflow assemblies are irrigation-contractor work, and the supply pipe to them is plumbing.
What are the signs?
Phoenix Water Services advises watching for surges in the water bill: unaccounted month-to-month or year-to-year increases may indicate a leak, and outdoor leaks often go undetected. Its leak guidance points to several places to look:
- Heads and drip lines. Big leaks develop when heads or drip emitters are broken off, cracked or spouting water.
- Valves and backflow preventers. Phoenix gives the rule of thumb "where there's water, there's a leak," and says to check often for moist or soggy ground around exposed valves, valve boxes or backflow preventers.
- Underground pipes. Soggy ground or sinkholes can be evidence of underground line leaks in sprinkler systems, evaporative cooling equipment, pool equipment or water main lines.
EPA notes that an irrigation system with 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.
How do you tell irrigation from the buildings?
Use the meter. EPA's commercial guidance describes reading the meter with all water uses off, then again an hour later. On a property with irrigation, shut the irrigation controller or its supply valve first; if the meter still moves, the leak is elsewhere. If it stops, the irrigation piping is the likely source. EPA also says submeters on major water-using systems such as irrigation help track unexpectedly high use. Meter checks are covered step by step.
EPA recommends a WaterSense-certified irrigation professional for auditing outdoor systems for leaks.
Who fixes which part?
Phoenix advises consulting an irrigation professional before repairing or replacing sprinkler valves, and says replacing parts on a backflow preventer should always be done by a qualified professional. Heads, emitters, valves and controllers are irrigation work. The pressurized supply pipe that feeds the irrigation system from the building's water service is plumbing, and so is a leak in a buried supply line. If the break is on the service line before the meter, it is the utility's side; see who owns the service line.
For HOAs, irrigation assemblies also need periodic testing; common-area backflow testing covers that requirement, and yard leak detection covers the general method.