A high water bill is one of the most common signs of a hidden leak, and the meter is the cheapest tool for confirming it. Before you call anyone, you can do a quick test that tells you whether water is leaving your property when nothing should be running.
Water and sewer service in Millbrae is provided by the City of Millbrae Public Works Department, so your bill comes from the city. That also means the city is the right place to ask about billing questions, while we handle finding and fixing the leak on your side.
How to check your meter for a leak
You do not need special tools. You need about twenty quiet minutes and a clear view of the meter.
Turn everything off
Shut off every faucet, stop the washer and dishwasher, and make sure nobody flushes a toilet. Turn off irrigation as well.
Read the meter
Locate the meter box, lift the lid, and look for the low-flow indicator, a small dial or triangle that spins when any water moves. Note the numbers on the register.
Wait and look again
Wait fifteen minutes without using water and check again. If the indicator is moving or the numbers advanced, water is escaping.
Narrow it down
Close the main valve at the house and check the meter again. If it stops, the leak is inside the house. If it keeps moving, the leak is between the meter and the valve.
This test splits the problem in two, which speeds up our work. If you try it and the numbers moved, call us with what you saw.
Where a high bill usually comes from
Toilets that run or leak
A worn flapper lets water seep into the bowl without a sound. It can waste a lot of water over a month and rarely triggers an alarm.
Hidden pipe leaks
Leaks inside walls, under floors, or in crawlspaces can run for weeks. A moving meter with every fixture off is the signature.
Underground service line
A leak between the meter and the house shows up on the meter but never inside the home. See water service line repair for how we handle that.
Irrigation and sprinklers
Cracked heads, broken valves, and buried lines leak without anyone noticing, especially when timers run before dawn.
Water heater and appliance leaks
A relief valve that drips, a failing connector, or a leaking washer hose adds to the bill gradually.
Irrigation leaks and backflow devices
Irrigation is easy to forget because it runs on a schedule and the water goes into the soil. A buried leak keeps the zone wet and the meter moving, and the first sign is often a soggy patch or a lawn that grows unevenly.
Backflow assemblies on irrigation are covered by Millbrae's Backflow and Cross-Connection Control Program, which requires testing when installed and once a year at the owner's expense. The water provider can cut service if a required assembly is missing or untested, so a locked valve or a shutoff notice may be about testing rather than a leak. We can look at the assembly and the line together.
Millbrae specifics for bills and meters
All of Millbrae's water comes from the San Francisco Regional Water System, and the city serves about 6,600 accounts through 11 pressure zones. A higher-pressure zone pushes more water through any small opening, so the same crack wastes more gallons at your address than it might elsewhere. We check the pressure at your house while we are tracing the leak.
A large share of Millbrae's homes date to the 1950s, based on Census counts of dwelling units, so toilets, valves, and supply lines may be original or only partly updated. Older fittings are a common source of slow leaks that never make a mess but show up in the bill.
The city also publishes an annual water quality report with contact details for Public Works. If your bill spikes and you have no leak, ask Public Works whether the meter read is correct before assuming a plumbing problem.
What we do when the meter confirms a leak
| Meter result | Likely cause | What we do |
|---|---|---|
| Moves with everything off, stops when the main is closed | Leak inside the house | Check toilets, fixtures, and hidden lines |
| Moves even with the main closed | Leak before the house valve | Locate and repair the buried line |
| Moves only when irrigation runs | Sprinkler or valve leak | Trace zones and repair the damaged part |
| Does not move but bill is high | Billing error or usage change | Compare reads and ask Public Works |
If the cause is not obvious, our leak detection service uses listening and thermal tools to trace the water without tearing into walls.
What affects the cost of finding and fixing a leak
What drives leak detection and repair cost
The price follows how hard the leak is to find and what it takes to repair.
Where the leak is
a toilet flapper is a small job, a buried line is a bigger one.
Access
finished floors and landscaping slow the work.
Number of leaks
one leak is simple, several in an old line change the plan.
Repair method
spot repair, reroute, or line replacement each have different costs.
Permit needs
permits may apply, and the Millbrae Building Division handles plumbing permits.
Call the 24/7 line for a clear price before work starts. Some water providers offer bill adjustments after a documented leak repair, so keep our paperwork and ask Public Works what they need.
Seen the meter move?
Call and tell us what the meter did. We will take it from there and give you a clear price.
Related water problems
A leak under the floor can raise the bill too, and slab leak repair explains how we find and fix those. If the leak is outdoors, water service line repair is the next step.
We also check homes in Burlingame, and the Burlingame page covers that area. Our line runs 24/7, so call whenever the meter catches your eye, day or night.
Questions about high water bills
Do the meter test. With everything off, check whether the low-flow indicator moves or the numbers advance. If they do, water is escaping. If not, the bill may reflect usage or a billing issue.
Yes. A worn flapper can leak quietly for weeks. Add a few drops of food coloring to the tank and see if color shows up in the bowl without flushing. If it does, the flapper needs replacing.
The City of Millbrae Public Works Department provides water service, so call them about meter reads and billing. We handle finding and repairing leaks on your side of the plumbing.
In many cases, yes. We use listening and thermal tools to trace the line and pinpoint the leak before any digging. Some repairs still need excavation, but we keep it as small as we can.
We handle leaks in supply lines and the backflow assembly. For cracked heads and valves in the system, we locate the problem and explain the repair. A locked valve may also be a backflow testing issue.
Some water providers have adjustment policies. We cannot speak for the city, so ask Public Works what documentation they want, and we will give you clear paperwork on what we found and fixed.
Yes, the call line is open 24/7. If water is flowing visibly, shut off the main valve first. Otherwise a meter check and a call is the best way to start.
A steady drip or a leaking toilet can waste many gallons a day, and that adds up on a monthly bill. Fixing it early costs far less than paying for months of lost water.
Sources and standards: The City of Millbrae Public Works water pages. The City of Millbrae 2025 Water Quality Report.