Got a call from a homeowner in Plano – water was pooling around the meter and backflow boxes, but the lawn past the sidewalk was completely dry. Couldn’t tell where the leak was actually coming from just by looking.
We rolled out and started our plumbing diagnostic.
What We Found
Two boxes side by side near the curb – the city water meter and the backflow preventer. Concrete walking path runs between them and the house. Water visible right at the boxes, but everything past the sidewalk looked dry – so the source wasn’t obvious.
We pumped the water out of the backflow box using a Milwaukee transfer pump. Within a few minutes, water started coming back in – flowing in from the side closest to the concrete sidewalk.
That told us everything. The leak was somewhere under that concrete path.
The Repair
Our plumber dug a trench down to the line. Sure enough – main water line was leaking right under the sidewalk. No way to access it without going through the concrete or under it.
We bored under the sidewalk, ran a brand new water line through, and added an access box for future maintenance. Cleaner than tearing up the homeowner’s concrete and easier on the lawn too.
While we were at it – the backflow preventer was in rough shape. Heavily corroded, rusted out. There was no point putting that old unit back on a brand new line, so we replaced it at the same time.
Tied everything together at a tee – one branch feeds the backflow, the other runs the new main line under the sidewalk into the house.
City Inspection
Backflow preventer replacements require a city inspection in Plano. We tested the new unit ourselves first, then called the city out. Inspector came, ran the test, signed off. All clean.
Customer is back up and running with a brand new line and a brand new backflow — no more leak, no more wasted water.
Why This Type of Leak Is So Common
Main water lines running under concrete sidewalks, driveways, or patios are one of the most common hidden leak spots we see in Plano, Frisco, McKinney, and surrounding areas. The line settles over time, the concrete shifts a little, and eventually you get a crack or a separated joint. Sometimes the water shows up at the meter or backflow box like in this case — sometimes you don’t see it at all and the meter just keeps spinning.
If you want to know how to check for this kind of leak yourself before calling a plumber, we put together a full step-by-step guide here: How to Check for a Main Water Line Leak in Your Yard
You can also read about how to shut off your main water valve in Texas so you can stop the bleeding fast while you wait for a plumber.
How do I know if my main water line is leaking?
The most common signs are water pooling near the meter or backflow box, wet spots in the yard with no irrigation running, a sudden jump in your water bill, or a city alert about high water usage. If your water meter keeps spinning with every fixture turned off, you almost certainly have a leak somewhere on the line.
Can a main water line leak under a concrete sidewalk be fixed without breaking the concrete?
Yes – in most cases we bore under the sidewalk and run a new line through. No need to tear up the homeowner’s concrete. It’s faster, cleaner, and saves you money on concrete repair.
Why does the backflow preventer get replaced too?
If the backflow is old, corroded, or rusted out, there’s no reason to reinstall it on a brand new water line. Plus the city of Plano requires backflow preventers to pass inspection – if it’s failing, you’ll have to replace it eventually anyway.
Does the city require an inspection after a backflow replacement?
Yes. In Plano, Frisco, McKinney, and most North Texas cities, any backflow preventer install or replacement has to be tested and inspected by the city before the job is closed out. We handle the testing and the inspection scheduling.
How long does this kind of repair take?
Depends on the depth of the line and how the sidewalk runs, but most of these jobs we finish in one day. Trench, bore, new line, new backflow, test, done.
How much does main water line replacement cost in Plano TX?
It depends on the length of the line, depth of the trench, whether boring under concrete is required, and if the backflow preventer needs replacing too. Most jobs fall in a typical range, but we always give a straight quote on-site after seeing the situation. Reach out for a real number based on your specific case.
Need a Plumber?
If you’re seeing water around your meter or backflow box, or your meter is spinning with everything off – call us. We handle main water line repair and replacement across Plano, Frisco, McKinney, Allen, Prosper, and Little Elm.
wish you all the best