High Water Bill? How to Tell if Your Sprinkler System Is the Cause

A water bill that suddenly jumps is stressful, and the sprinkler system is often the first suspect. Sometimes it is the cause. Other times the problem is inside the house. This article explains how to sort out where the extra water is going, step by step, before you spend money on repairs you may not need.

Compare Against the Same Month Last Year

Outdoor water use in Fort Worth swings a lot with the seasons. A bill in late July will almost always be higher than one in January, because the lawn needs more water in the heat. Before assuming something is wrong, compare the bill with the same billing period a year earlier. Look at the gallons used, not just the dollar amount, since rates can change. If usage is well above last year’s for the same period and the weather was similar, something has likely changed.

Rule Out Inside Leaks

Indoor leaks are a common cause of high bills. A running toilet can waste a large amount of water without making much noise. Check these first:

• Toilets that run, refill on their own, or hiss
• Dripping faucets and showerheads
• Water heater relief valve dripping
• Wet spots under sinks or around the water heater
• Hose bibs left partly open outside

A simple toilet test is to add a few drops of food coloring to the tank and wait fifteen minutes without flushing. If color appears in the bowl, the flapper is leaking.

Do a Meter Test

Turn off every fixture inside and outside the house and make sure the sprinkler system is not running. Find the water meter and watch the leak indicator, a small triangle or dial that spins when water flows. If it moves, water is flowing somewhere.

Next, close the irrigation isolation valve and watch again. If the indicator stops, the leak is on the irrigation side. If it keeps moving, the leak is in the house or on the service line between the meter and the house. Our water meter leak test guide walks through this in more detail.

Sprinkler Causes of a High Bill

A mainline leak

The mainline between the backflow preventer and the zone valves holds pressure all the time. A crack or a failed fitting here leaks around the clock. It is the most common sprinkler cause of a sudden jump. See our article on signs of a hidden sprinkler leak.

A valve that will not close

If a zone valve sticks open, that zone can run for hours or all night. You may notice one area of the yard that is soaked in the morning, or hear water running when the system should be off. Our guide to a zone that will not turn off explains the causes.

A broken head or lateral line

A snapped riser or a cracked lateral pipe pours water out every time that zone runs. Since lateral lines only hold pressure when their zone is on, these leaks will not show on a meter test with the system off. You have to watch each zone while it runs.

A schedule that waters too much

This is not a leak, but it has the same effect on the bill. Common programming problems include:

• More than one program running, so zones water twice
• Multiple start times set when only one was intended
• Seasonal adjust set high from summer and never turned back down
• Run times that are much longer than the lawn needs
• A rain sensor that was bypassed, so the system waters during and after rain

Fort Worth limits residential irrigation to two assigned days a week. If your controller is watering more often than that, it is also out of compliance. Our guide to programming for Fort Worth’s watering days can help you clean it up.

Look at the Yard for Clues

Walk the yard the morning after a watering day and again a day later. Look for areas that stay soggy, puddles near heads, water in the gutter, or grass that is much greener in one strip. Each of these can point you toward the problem zone.

Check the Controller History

Some newer controllers keep a log of when each zone ran and for how long. Smart controllers often show this in an app. If yours has this feature, look for extra cycles or unexpected run times. Our article on smart sprinkler controllers covers what those logs can tell you.

When You Find the Cause

If the problem is programming, fix the schedule and watch the next bill. If it is a leak or a stuck valve, close the irrigation isolation valve until it is repaired. That stops the waste while you arrange the fix. Leaving the system off for a few days is better than watering the street.

Why It Is Worth Fixing Quickly

Beyond the cost, water running onto the street or sidewalk counts as runoff under Fort Worth’s watering rules, and runoff is listed as water waste. A leak near the foundation can also keep that soil wetter than the rest of the yard, which can affect the house on expansive clay.

If you have narrowed it down to the irrigation system but cannot find the problem, our sprinkler repair team can locate the leak or faulty valve and fix it.