Main Water Line FAQ
Twenty questions we hear from homeowners in Diamond Bar and nearby cities about main water lines, grouped into five topics.
- Since 2005
- Open 24 hours, 7 days
FAQ: topic 1 of 5
Leaks and warning signs
How can I tell if my main water line is leaking?
Turn off every fixture and appliance, then watch the water meter for 30 minutes or more. If the dial or sweep hand moves while nothing is running, water is escaping somewhere. Close the shutoff at the house and check again; if the meter still moves, the leak is most likely on the main line.
Why is one patch of my lawn always wet?
A strip of soggy or unusually green grass that does not match your watering pattern often sits directly above a leaking pipe. It can also be a broken sprinkler line, so it helps to run the meter test with irrigation turned off.
My water bill jumped but nothing changed at home. What now?
Compare the last few bills to the same months a year earlier. A steady climb with no change in household use points to a hidden leak. The meter test will usually confirm it, and leak detection can locate it without guesswork.
Is it an emergency if water is coming up through the ground?
Yes. Water surfacing in the yard or sidewalk means a pipe has failed under pressure. Close the main shutoff at the house to stop the flow, then call us. If the water is coming up on the street side of the meter, also call your water provider.
FAQ: topic 2 of 5
Repair or replacement
Does one leak mean I need a whole new line?
Not necessarily. If the pipe is fairly new, the damage has an obvious cause, and the pipe on either side looks sound, fixing the one section is often enough. Repeat leaks or corroded pipe are what tip the decision toward replacement.
How old is too old for a main water line?
There is no single cutoff, because material, soil and installation quality all matter. Galvanized steel from the middle of the last century is commonly at or past the end of its useful life. Copper and PEX lines installed more recently usually have many years left.
Can you replace the line without tearing up my driveway?
Often, yes. If the old line runs under concrete, we can usually run the new one along a different path through soil and connect it at both ends. That approach is called rerouting, and it leaves the slab alone.
Will you tell me if a repair is enough?
Yes. If a repair will give a sound line many more years, we say so. We explain what we found in the ground and why we would choose one option over the other.
FAQ: topic 3 of 5
Pipes and materials
What pipe do you use for a new main line?
Usually copper or PEX. We pick based on the length of the run, the route, the soil and how the line connects at each end, and we explain the choice. If you prefer one material, tell us.
Why does galvanized pipe cause low pressure?
The zinc coating on galvanized steel wears off over the decades, and the steel then rusts from the inside. The rust builds up on the pipe walls and gradually shrinks the opening that water flows through.
Is PEX allowed in California?
Yes. After a back-and-forth process that ran from 2009 into 2010, PEX was accepted into the California Plumbing Code and is now commonly used for water lines.
Should I upsize the line when it is replaced?
It is worth considering, especially if the house has added bathrooms or irrigation zones since it was built. A replacement is the cheapest moment to make the change, since the trench is already open.
FAQ: topic 4 of 5
Permits and who is responsible
Who owns the pipe between the meter and my house?
In most local water systems, the homeowner does. The water provider owns the main in the street and the meter, and responsibility shifts to the property owner on the house side of the meter.
Do I need a permit to replace my main water line?
Generally, yes. The California Plumbing Code requires a permit to replace plumbing pipe, and Diamond Bar specifically lists water service work among the plumbing jobs that need one. Small leak repairs that do not replace any pipe are an exception.
Who handles permits in unincorporated areas?
Communities without their own city government, such as Rowland Heights and Hacienda Heights, go through Los Angeles County for building and plumbing permits.
Will my homeowners insurance pay for this?
That depends entirely on your policy. Some cover water damage from a sudden leak but not the pipe itself, and some offer separate service line coverage. Your insurer is the only one who can answer for your policy.
FAQ: topic 5 of 5
Calling and scheduling
Can I book online or send a message?
We work by phone only. Calling gets you a real person and an answer right away, which matters when water is running.
How soon can someone come out?
We offer same-day service, and urgent calls such as a burst line or a house with no water move to the top of the list.
Do you charge more at night or on weekends?
We discuss pricing after we understand the job, not over the phone. Ask about timing when you call and we will explain how the visit works.
Which cities do you work in?
Diamond Bar and nearby cities including Walnut, Rowland Heights, Hacienda Heights, Chino Hills, Pomona, West Covina, Brea, Yorba Linda, Chino and City of Industry. If you are close by but not listed, call and ask.
Questions this page does not answer
These answers cover the general picture. For an answer about your own line, call us and describe what you are seeing. You can also read our water line guides, the cost guide or the full list of services.
Have a question about your water line? Call us.
Phones answered 24 hours a day.