How do I find a water leak in my yard?

The water meter is the single best tool, and it takes about ten minutes.

1. 1Stop all water use. Turn off the irrigation controller. Make sure no faucet, hose, toilet or appliance is running, and that the ice maker and washer aren't filling.
2. 2Find the meter. Cal Water says it's usually at the curb. Lift the lid and look at the flow indicator, which is typically a triangle or star.
3. 3Watch it. Cal Water's rule: if the flow indicator is turning, you have a leak.
4. 4Narrow it down. Shut off the valve at the house, then check the flow indicator again. If it still turns with the house valve closed, the leak is outside the house, on the buried line, the irrigation or a fixture past the valve. If it stops, the leak is inside.

The EPA uses a similar check, comparing the meter before and after a two-hour period with no water use. Our page on how to do a water meter leak test has the full steps. If your bill is what tipped you off, a high water bill with no visible leak walks through the usual suspects.

One caution. Phoenix says not to try to shut off the water at the city's meter yourself. Phoenix says to use the valve near where the water enters your home, and if that valve doesn't work or is broken, to call the city at 602-261-8000 to have the water turned off at the meter.

Once the meter says water is escaping, the ground often gives it away. Cal Water tells homeowners to look for "wet spots or patches of grass that are greener than the rest of your yard," which could indicate a leak in the pipe. A leaking pipe waters that spot all day, so it stays green and damp when the rest of the yard has dried out. Other signs to watch for:

• Wet or muddy patches that appear even when you haven't watered
• Sunken or soft ground along the path of the line
• Running or hissing sounds when no water is in use
• Unexpected increases in your water bill

Note where each sign is. A wet patch in a line between the meter and the house points to the main line. A soggy spot around a sprinkler head points to irrigation. Damp soil against the foundation near a hose bib points to that fixture.

In the desert, a wet spot shows up fast, because the ground around it is otherwise so dry. That works in your favor.

Split the problem into four parts and test them in order.

Irrigation. The EPA says an irrigation system with a leak just 1/32 of an inch across can waste about 6,300 gallons a month. That's a hairline. Run each zone, one at a time, and look for geysers at broken heads, soggy spots along drip lines, and zones that stay wet long after they shut off. Cal Water recommends checking for broken sprinkler heads monthly. Our guides on fixing drip irrigation and why a sprinkler system won't shut off cover the usual repairs. A stuck valve can look exactly like a buried leak, so run this check before you assume the worst.

Hose bibs and outdoor fixtures. Look at the spigot, the wall behind it, and the ground below. A drip from a hose bib is often a worn washer or a failed vacuum breaker, not a buried pipe. See outdoor faucet and hose bib leaking.

The pool. If you have one, Cal Water says a pool losing an eighth of an inch or more per day likely has a leak. Evaporation in Phoenix is real, so compare against a bucket test. How to find a pool plumbing leak covers it.

The buried water line. If the meter moves with irrigation off, no fixture is dripping, and the pool is fine, the buried pipe between the meter and the house is the suspect. That's the main line.

Don't grab a shovel yet. A few minutes of prep saves a lot of grief.

1. 1Mark it. Stick a flag or a stone at the wettest spot and take a photo. Wet ground spreads, and the surface spot isn't always where the pipe is broken.
2. 2Write down the meter reading and the time. A second reading later tells a plumber how fast water is escaping.
3. 3Turn off what you can. Close the irrigation zone valve if it's the sprinkler line, or the house valve if it's the main line.
4. 4Call before you dig. Arizona 811's notice period is two working days, excluding weekends and state-recognized holidays, and a ticket gets underground utility lines marked. A shovel through a gas or electric line is a far bigger problem than a wet lawn.
5. 5Keep the kids and pets off the spot. A saturated patch of desert soil can slump.

A small pinhole in a buried line can also run for weeks before you see anything, which is why the meter check comes first and the digging comes last. In desert soil, water can travel underground along the pipe before it surfaces, so the wet spot can sit several feet from the actual break. That's another reason to have the leak located with equipment before anyone digs. How deep that line sits isn't something to guess; see how deep a residential water main is buried in Phoenix.

In Phoenix, the meter is the dividing line. The city says issues from the street to the meter are its responsibility, and issues after the meter belong to the homeowner. A leak in your buried line, your irrigation or your hose bibs is yours to repair, and you pay for the water lost. If the wet spot is at or before the meter, call the city. Our page on who to call about a water leak in Phoenix has the numbers.

Call a plumber when the meter is moving and you can't find the source in twenty minutes, or when the leak is in a buried line. Buried leaks are hard to place by eye, and plumbers use listening gear and pressure testing to find the spot so you don't dig up the whole yard. Ignored leaks erode soil, can damage foundations and waste water. If the line turns out to be failing, what a main water line is and when it's replaced explains the options, including the city's replacement program for galvanized lines.

HQ gives free estimates and upfront pricing, and we offer 24/7 emergency service if water is running now. Shut off the water at your house valve first. That stops the leak while you sort out the rest.

Spring is a good time to walk the sprinkler zones before watering ramps up. See what plumbing to check in spring.