For most homes, the water usage is higher outdoors where the overflow flows into the storm drains. The overflow from indoors (and waste) goes into the sewage system. Here’s why:

1. If you find a sudden spike in your water bill, you can find out right away whether it’s from extra use indoors or outdoors by testing each meter. You’ll then have to check only half the area for leaks.
2. Since sewage charges are calculated from all meter readings except dedicated irrigation meters, you may be paying too much. Check to see how sewage is billed. If it’s billed by a flat charge, you’re ok. If it’s billed by the amount used, you may be paying sewage charges on your landscape use, which you don’t owe.
3. Once a dedicated meter is installed, check the main meter (called a mixed meter) to see how much water you normally use per month for indoor use. That’s the only thing sewage should be billed on—indoor use to help maintain the public sewage system. Multiply that amount by the sewer rate charged by your water provider. If you have been paying more than that each month, the water provider may owe you money.

Once you have installed the meter, check to see if you have been overcharged in the past. If you have, call the water supplier and they will refund you.

Irrigation System Troubleshooting

If you have a dedicated meter for your irrigation system, you can use it to check for leaks. Make sure that all water is turned off before starting, both inside and out.

To check for leaks, set aside a day to turn off the irrigation system and check the water meter. If the meter is still running or the leak indicator is showing, there is a leak.

The next step is to locate the leak. First, check the irrigation controller, then the valves, and finally the sprinklers. If you can’t find the source of the leak, you may need to check for leaks in underground pipes. You may need to buy special equipment to do this.

For the initial checks, all you will need is:

• Paper and pencil
• A slew of irrigation flags (small, bright, triangular flags hooked to a 6″ thin metal rod that you stick in the ground)
• Gardening gloves
• A trowel

The first step is to check your irrigation controller.

Irrigation Controller Check

When you look at a controller, you are checking to see if the programming is reasonable. A sprinkler station may lose its programming and go on default, which may be the wrong schedule for you.

Sprinkler Valves Check

The next step is to check each of your valve boxes. They should be dry – if they’re wet, inspect them carefully for any damaged parts, loose wiring, or water leakage. If you find any problems, flag the box and leave the cover off so you can come back to it later.

If you are repairing the system yourself, estimate the cost of parts you will need and make repairs all at once. If you are not repairing the system yourself, start a list of problems for your landscaper or plumber to take care of.

Sprinkler Stations Check

Start by checking the controller and valves to see if they are functioning properly. If you have a large landscape, you will need help from another person to turn the stations on and off and to walk around and take note of any problems with the sprinklers. Be sure to carry flags to mark any problems you find so that you can repair them later.

Turn the stations on one by one. You will be looking for several indications of wasted water:

• Water geysers—tall spouts of water that indicate missing or broken spray heads.
• Floods around the base of a sprinkler. The grass may need to be cut shorter or a short riser replaced with a taller one. There could also be an old valve that is not shutting off properly, especially if a number of sprinklers in the same area are leaking. You might want to check the valve that supplies that sprinkler again.
• Misaligned spray head shooting water into a nearby obstruction or over the sidewalk or parking lot, instead of watering grass.
• Water spurts between sprinkler heads—indicate a broken pipe (lateral line) that has already blown out the soil above it.
• Flooded areas between sprinklers can indicate a slow, steady leak in a lateral line underground. You will have to dig down to find the actual spot. 
• Spurts of water at the base of a sprinkler––indicates a broken seal where the nozzle or riser meets the supply line beneath.

Large landscapes typically have various issues that need to be fixed on a regular basis. At a minimum, routine maintenance should be conducted once a month to save water. Once all necessary repairs have been made, the irrigation meter can be tested again.

If your water meter is still reading water usage even when you know all water is turned off, there may be an invisible leak underground.

Underground Plumbing Check

The water that continues to run is called “unmetered water use.” Make sure to check the meter again and turn off all the water that is being measured. The water that continues to run is known as “unmetered water use.” If the needle is still moving, then this time, you will need to check for water pressure and the sound of running pipes:

• Turn the stations on again, one by one, starting with the one closest to the main pipe where water comes into your property—usually located near the meter itself.
• Look at the difference in water pressure (the height and size of spray) between the station closest to the main pipe and the one next to it. If there is any difference at all, it should be a barely noticeable lessening as you go further and further back into the property. Test all of your stations this way, comparing the water pressure of one set of sprinklers with those of the station after it.
• If you have a hidden leak, at some point, there will likely be a noticeable drop in water pressure. This means that some water is leaving the pipe in that station before reaching the sprinklers. If the entire station is noticeably lower, the leak is probably fairly close to the beginning of that station. If it doesn’t get lower until closer to the end, then that’s where the leak is—near the end.
• Sometimes the water gushing through pipes will be loud enough that, if your hearing is good, you can actually hear where the leak is. If not, this is where your equipment comes in. The microphone will pick up and magnify the sound of the water (or the pipe vibrating with it), and the meter in your hand will read the intensity of the sound as you move along the pipe. The most intense reading is likely the location of the leak. Flag it.

Locating an Underground Broken Pipe

Step 1: Trace the Path of the Irrigation Sprinkler Lines

If the people who installed your system gave you a map, you’re lucky. If you don’t have a map, you’ll have to do a bit of digging to figure out how the system is laid out.

Thankfully, you don’t have to dig out the whole yard. If you know these basic facts about irrigation system installation, you’ll have an idea of where to start digging: 

• Irrigation pipes are made up of straight and T-joint pipes. This means that if you find one, the next pipe should be straight ahead or to the left or right at a 90-degree angle.
• The sprinkler pipes are buried about 8–12 inches into the ground. Because you won’t find the pipes buried too deep in the ground, there’s no reason to keep digging in one spot if you don’t see anything within the 12-inch range. 
• Most irrigation system pipes are made of PVC (older systems had metal pipes), so you can use pipe detectors to pinpoint their location.

To find the first pipe, start by looking near the valve boxes and areas close to the sprinkler heads. Once you find the first pipe, use tape or spray paint to map out the rest of the system.

If you dig 2 to 3 feet and don’t find anything, you may be off course. Try digging again to make sure.

Be careful when you are digging and hold your shovel at an angle to avoid hitting the pipes.

Step 2: Isolate the Source of the Leak

Now that you know the layout of the pipes, you can use sound-detecting tools to pinpoint the location of the underground leak.

Find it by Digging

To find the area where leaks are happening, you will need to shut off the water to the irrigation system so that the ground can dry up.

Following the Sounds

You can also isolate a leak if you pay attention to the sounds of water flowing through the pipes. This requires specialized equipment like:

• Leak noise locators
• Leak noise correlators
• Acoustic testing kit with water leak microphone and headset

These tools are designed to pick up the sound of an underground leak along irrigation lines.

A leak can be difficult to locate because the water damage may not be in the same place as the leak. If you see water damage, it is important to look for the source of the leak.

In order to find the cracked pipe, you will need to inspect the area around the leak. This means looking at several inches of pipe on each side of the leak.

How to Repair a Broken Underground Pipe

If you find a pipe, it’s important to take care of it right away. For instance:

• The water may seep into and weaken your home’s foundation, decks, patio, and any other nearby structures.
• A steady leak can ruin utility lines. 
• If the leakage is excessive it may cause underground cavities and sinkholes.

Here’s how you can repair the pipe before the leak wreaks havoc on your home:

1. Carefully dig at least 1 foot deep and 1 foot wide to fully expose the pipe to prevent any dirt from entering the irrigation system while you work. 
2. Measure the broken pipe and cut out a new length of piping of the same length
3. Cut off the length of the broken pipe from the irrigation system about 4–10 inches long depending on the extent of the leak. 
4. Put in a new length of PVC pipe and attach it using couplers on either side. Use pipe cement and PVC primer to keep the joint in place.
5. Leave it to dry for 24 hours to dry completely.
6. Now turn on the water at low pressure initially. Gradually increase water pressure and see if the joint holds out. If there’s no leaking, cover the hole.

Voila, your broken pipe and water leakage problem is no more!

To repair your lawn, cut out small square patches of grass in the areas you want to fix, taking care not to disturb the roots. Lift the grass patches, roots and all, carefully.

After you finish, you can just put the grass back, and it will grow like it never happened.

Water Provider Assistance

If you have ruled out factors that could explain a high water bill, such as checking for leaks and floods and finding that the water pressure is normal, then the problem may be with the water meter. In that case, you should call your water provider.

Please tell me all of the tests you have run and I will send someone over to check the meter. If it is an old meter, it is possible that something is wrong with it. If it is a newer meter, it is possible that it was not installed properly. If they find that everything is okay, then it is time to call a plumber.

You will benefit from every problem that is found and fixed while trying to locate the leak. It does not matter who pays for it or what the final result is.

Water Use Audit

If you want to save even more water, you can call for a water audit. This will show you which fixtures can be retrofitted to use less water automatically. You will also get a landscape watering schedule that is customized for your area and the types of plants you have. Some water suppliers do water audits for free, so you should ask about that when the technician comes to check the meter. Also, many suppliers offer a complete indoor-outdoor audit as part of their water conservation program. You may as well ask about that too.