Signs of a Main Water Line Leak

Unexplained Water Bill Increase

A meaningful, persistent increase in your water bill without a corresponding change in usage — no new irrigation, no filled pool, no extra occupants — is the earliest and most common indicator of a main water line leak. Because the main line is pressurized constantly, even a pinhole leak runs 24 hours a day and can lose significant water volume daily.

Compare your current bill to the same month in prior years to filter out seasonal variation. If you see a jump of 20 to 50 percent or more without explanation, a hidden leak is near the top of the diagnostic list. Redlands Water and Power provides monthly usage data online — tracking usage week by week can help you identify when an unexplained increase started.

Sudden Drop in Water Pressure

A main line that's losing water volume through a significant leak will reduce the pressure available to fixtures throughout the house. If your morning shower pressure dropped noticeably compared to a month ago, and all fixtures in the house seem less powerful than before, and nothing has changed in your household's usage, a main line leak is worth investigating.

Compare with neighbors if you can — if they're experiencing similar pressure drops, it's likely a municipal system issue rather than your line. If only your house has the pressure drop, the problem is between the meter and your home.

Main line pressure drops can also result from a main line break that's partially restricting flow without fully failing. Even a hairline crack in the main can cause progressive pressure reduction as the opening enlarges.

Wet or Sunken Areas in the Yard

The main water line runs from the street meter through the front yard to the house foundation. A leak in this line saturates the soil directly above and around the pipe. The surface signs: a spot in the yard that's noticeably wetter than surrounding areas even without recent rain or irrigation, grass that's unusually green and lush in a strip or patch over the line's path, or in more advanced cases, a slight depression or soft area where water has eroded the soil.

The lush-grass indicator is particularly notable in Redlands' dry summer months. A strip of brilliantly green, fast-growing grass across an otherwise drought-stressed lawn is a classic sign of a water line leak providing unintended irrigation below ground.

If you notice any of these yard conditions, check whether they're aligned with the path from your water meter to your house foundation — that's where your main line runs.

The Water Meter Test

The water meter test is the most reliable DIY method to confirm a leak exists in your system:

• Step 1: Turn off every water-using fixture and appliance in the house. This includes the icemaker, irrigation timer, and any running toilets. Everything should be completely off.
• Step 2: Locate your water meter (typically in a ground-level box near the street) and note the reading, including the small triangular or circular flow indicator if present.
• Step 3: Wait 15 to 30 minutes without using any water.
• Step 4: Check the meter again.

If the meter reading has changed or the flow indicator is moving with everything off, water is leaving your system somewhere. If the main shut-off inside the house was also turned off during the test and the meter still moved, the leak is specifically in the main line between the street and your house shut-off.

Sound of Running Water

In some cases, a significant main line leak can be heard — a faint rushing or hissing sound that seems to come from outside the house near where the main enters the foundation, or from the ground in the front yard. This is more noticeable in quiet conditions and on properties with minimal landscaping to muffle sound.

Professional leak detection uses acoustic amplification equipment to hear small leaks that would be inaudible to the human ear. Ground microphones and electronic amplifiers can locate a leak within a foot or two without any excavation — this pinpoint localization is what makes professional leak detection cost-effective, since it means only a small area needs to be opened for the repair rather than excavating the entire line.

What to Do if You Suspect a Leak

If you've identified signs of a potential main line leak, the first step is to confirm it with the water meter test. If the meter confirms water loss, call for professional leak detection before any digging. Knowing the precise location of the leak means a targeted repair rather than unnecessary excavation.

Main water line repair options depend on the extent and nature of the damage. A localized pipe failure can sometimes be spot-repaired with a pipe clamp or section replacement. Older galvanized or copper lines with widespread corrosion may warrant full line replacement, which can also be done using trenchless methods in many situations — pulling new pipe through the old pipe's path without open-trench excavation.

Call (207) 419-2600 for main water line leak detection in Redlands. We identify leaks precisely and give you clear repair options before any work begins.