- Rule out toilets, irrigation and seasonal changes first.
- A moving meter with everything off means water is escaping.
- Outside leaks on the service line are the owner's responsibility after the meter.
A meter doesn't guess. If yours recorded more water this period, water went through it. The question is where it went, and the answer falls into one of three buckets: normal use you didn't notice, a leak inside the house, or a leak outside, including in the buried water line.
First, rule out the ordinary
- Season and irrigation: summer watering can raise use sharply. Was a timer changed or a zone left running?
- New occupants or guests: an extra person or two for a few weeks shows up clearly.
- Billing period length: check the number of days; a longer cycle means a higher bill.
- Pools, spas and new landscaping all use significant water while filling or establishing.
If none of these explains it, move on to leaks.
Check the indoor usual suspect: toilets
A toilet flapper that doesn't seal can waste a lot of water silently. Put a few drops of food coloring in the tank, wait 15 minutes without flushing, and look in the bowl. Color in the bowl means a leak. Also listen for a water heater or water softener cycling when nothing is in use.
Then ask the meter
With everything off, watch the meter's low-flow indicator. If it moves, close the building shut-off. If it still moves, the leak is outside the house, in the service line or the irrigation system. This is the same check the City of San Luis Obispo describes in its leak guidance. Our meter check walkthrough has the full steps, including how to isolate irrigation.
Use your usage data
If your meter has an AMI radio, the City's customer portal shows usage over time and lets you set leak notifications (City of San Luis Obispo). A healthy home has quiet periods, typically overnight, with almost no use. Continuous flow around the clock is a strong leak signature, and the graph may even show roughly when it started.
If the leak is in your water line
In San Luis Obispo, the City maintains the pipe up to and including the meter; the service line after the meter is the property owner's responsibility (City of San Luis Obispo). So a leak on your side needs a private repair. If you suspect a problem at the meter itself or on the street side, contact the City's Utilities Department first. It's also reasonable to ask the utility whether any leak-related billing policy applies to your account.
Quick summary
| Finding | Likely cause |
|---|---|
| Meter still with everything off | Usage change, not a leak |
| Dye appears in toilet bowl | Leaking flapper |
| Meter stops when building valve closed | Other indoor leak |
| Meter moves with house and irrigation isolated | Water service line leak |
If the evidence points outside, our page on water line leak repair explains how the leak is pinpointed and fixed, and our homepage covers water line repair in San Luis Obispo in more detail.