7 Signs of a Broken Main Water Line

By Water Line Repair Pros

Your main water line runs underground from the water meter to your house, so when it breaks, you usually can't see the damage directly. What you see instead are clues: in your taps, your yard, your bill and your meter. Spotting them early can save water, money and a lot of soggy lawn.

Here are the seven most common signs of a broken main water line, what each one tends to mean, and what to do next.

The 7 signs of a broken main water line

1. A sudden drop in water pressure everywhere

If one faucet is weak, the problem is usually that faucet. If every tap, shower and hose bib loses pressure at the same time, the problem is upstream, and the main line is a prime suspect. Water escaping through a break never reaches the house.

Before you assume the worst, check with neighbors or your water provider. A main break or maintenance in the street can cause the same symptom and isn't your responsibility.

2. Wet, soggy or sunken ground

Water from a buried break has to go somewhere. Look along the route between the meter box and the point where the pipe enters your house. Warning signs include:

• A patch that stays damp or muddy days after any rain or watering
• Water pooling or bubbling up from the ground
• A strip of grass that's noticeably greener or faster-growing than the rest
• A dip or small sinkhole forming over the line's path

3. A water bill that jumps for no reason

Compare your latest bill with the same period last year. If usage has climbed but your habits haven't changed, water may be leaking out before it reaches the house. Underground leaks can run for weeks unnoticed, so the bill is often the first clue.

4. The meter moves when nothing is on

This is the most reliable sign, and you can check it yourself in a few minutes. See the meter test below.

5. Dirty, rusty or cloudy water

A break can let soil and sediment into the line, and disturbed pipe can release rust. If the water suddenly runs brown or cloudy at every tap, and your provider isn't reporting work in the area, the main line may be damaged. On older galvanized lines, rusty water can also point to a pipe that's corroding from the inside, which is covered in our guide to galvanized water line replacement.

6. Hissing or running-water sounds

With everything in the house turned off, listen near the meter box, near where the line enters the house, and at the main shutoff valve. A steady hiss or trickling sound when no water should be moving is a strong hint that it's escaping somewhere.

7. No water at all

A complete loss of water can mean a severe break on your line. It can also mean a shutoff by your provider, so check that first. If the street has water and your house doesn't, call for help right away.

How to test with your water meter

1. Turn everything off. All taps, the washing machine, dishwasher, irrigation and ice maker. Make sure no toilet is refilling.
2. Find the meter. It's usually in a box in the ground near the street or sidewalk. Lift the lid carefully, as spiders and other critters like to live there.
3. Look at the leak indicator. Many meters have a small triangle or wheel that spins when even a little water is flowing. Note the reading or take a photo.
4. Wait 15 to 30 minutes without using any water, then check again.
5. Narrow it down. If the meter moved, close your home's main shutoff valve and repeat. If it still moves with the house shut off, the leak is very likely on the buried line between the meter and the house.

What to do right now

• If water is flowing or pooling: close your home's main shutoff valve if you can do it safely. It's usually near where the line enters the house. Turn it clockwise.
• Keep people and cars off soft ground. Water can wash out soil and leave voids under the surface.
• Check whether it's your side. Leaks at the meter or in the street belong to your water provider. Leaks between the meter and the house are usually yours. Our guide on who is responsible for the water line explains the split.
• Call a professional to locate and fix the break. For urgent situations, emergency water line repair is available 24/7.

Is it a break or a slow leak?

A full break usually shows up fast: a big pressure drop, water surfacing in the yard, or no water at all. A slow leak is quieter. It might only show up as a creeping bill, a meter that ticks over, or one damp spot that never dries.

Both need attention. A slow leak can still wash soil away from under walkways and driveways over time. When the source isn't obvious, water line leak detection pinpoints it before digging, so only the right spot gets opened up.