If you use city water, there is a main water pipe which runs underground from the street through your front yard to the house. This pipe can either exit the ground and enter the house near the street side wall, or it may enter the house from the ground.
The depth of water pipes in the ground is not standard. It however must be buried below your area’s frost line. How deeper you go below the frost line depends on you area’s building code. Sprinkler lines don’t need to be buried below the frost line.
If you use water from a well, a water pipe will also run underground from the well to the pressure tank. Another pipe from the pressure tank will supply the rest of your house with water.
It is important to locate the main water line to your house in case you suspect you have an underground leak, want to establish what type of pipe you have or when you want to replace the pipe.
To find the main water line to your house, start by locating your water meter or main water shut off valve. The main water line to your house is connected to the city’s water lines and connects to the water meter/shut off valve in a straight line underneath your front yard.
You should definitely find out where your water meter and shut off valves are located if you want to find an underground leak in your front yard.
One thing you can be sure of is that the main water pipe enters the house from the side that faces the street. If you have a private well, the water pipe can enter the house from any corner. The key to finding it will be in located the well itself.
The pipe will be buried between where the well and pressure tank are located. These pipes are easier to find than main water lines from city water.
3 Ways to Find a House’s Water Line
There are 3 ways you can use to find buried main water pipes to a house and where they enter the house. Hopefully one of them will work for you.
1. Locate your Water Meter
This method works for water meters that are located outside the house. In extremely cold areas, water meters are installed inside the house close to the main shut off valve.
If your water meter is outside the house, it will be located close to the street near the curb or sidewalk. Look for a metal or concrete lid with “Water Meter” or “Water” written at the top.
Use a long screwdriver to lift off the lid. Be careful as it is not unusual to find snakes, spiders and other animals underneath the lid.
With the lid off, you can now see the main water line that connects the city water and your house. The pipe runs underneath your front yard in a straight line to the closest wall of the house.
Depending on where you live, the pipe can emerge from ground when it reaches the wall closest to the street, where it then enters the house. This allows the installation of a shut off valve and/or pressure reducing valve also know as pressure regulator.
In cold areas, the pipe will still enter the house from the ground especially when you have a basement or crawlspace.
If you need to dig, start digging from the water meter towards the house in a straight line.
When you want to eliminate errors, you can buy a device called a pipe locator. These locators are fitted with sensors that can detect metal and plastic water pipes.
Just walk around your yard in a straight line from the water meter towards your house aiming the locator’s sensor on the ground. Depending on the type of sensor you have, it will either beep or visually show the pipe location on a screen.
2. Locate your Main Water Shut off Valve
Depending on where you live again, your main water shut off valve will be located on external wall or inside the house.
If it is installed outside the house, it will be on the street side where the main water line emerges from the ground and enters the house. This valve could either be a gate valve (with a knob) or a ball valve (with a lever).
The main water line will be found underground between the shut off valve and the water meter. If you don’t find the shut off valve outside the house, it will definitely be in the house.
For water shut off valves that are located inside the house, they will be found in the basement, crawlspace, garage or utility room. The valve could be very near to the floor or above your your head where a pipe emerges from the wall.
Usually, shut off valve are located very close to the water meter. Follow the water meter’s cold water supply pipe and you will surely find your shut off valve.
Shut off valves are not neat to have in the house. These means they could be walled up or hidden in closets and may be hard to find especially in finished basements.
Luckily for you, shut off valves will always be installed on the street side of the house, helping you narrow down your search.
Notice how the pipe enters the house. Main water lines to the house do not have elbows. They are installed in a straight line from the shut off valve to the water meter/street.
3. Look for an Outside Bib/Spigot
Can you see an outside spigot/bib on the street side of your house? This is usually installed on the wall facing the street.
If you can see the bib, that is where the main water line enters your house. Dig around this bib and you will find the pipe below your area’s frost line.
Finding the main water line to your house is easy if you have both the water meter and bib/shut off valve outside the house.
How to tell if Your Main Water Line is Leaking
To check if your main water line to you house is leaking, start by turning off your main water shut off valve. Turn it all the way clockwise if it is a gate valve or perpendicular to the pipe if it is a ball valve.
Head over to your water meter and check if the leak detector is spinning. The leak detector is the small piece in the middle of your water meter which looks like a gear or small triangle.
If it is spinning, you indeed have an underground leak. Finding the exact location of the leak is not easy and you may need the services is a professional plumber.
Check out this post to learn how to read a water meter.
Finding the main water line to your house is a also a good chance to know what type of pipe you have.
Plastic and copper pipes are the recommended ones and are easy to identify. What you may confuse is galvanized pipes and lead pipes.
If you have lead pipes you should have them replaced as soon as possible. For more information on lead main water service lines check out this post.
If you have galvanized pipes, they will most likely be corroded. They are also magnetic while lead pipes are not.
And basically that is how to find the main water line to your house. I hope this guide was helpful.