How to Do a Water Meter Leak Test in Portland: Step-by-Step

Find Your Portland Water Meter First

Portland Water Bureau meters are located in a concrete or plastic box set into the ground near the public sidewalk, typically directly in front of the property. Lift the lid — some require a meter key (T-wrench available at hardware stores for ~$15), others have a pull handle. Inside you’ll see the meter face: a register showing total water use, a flow indicator (small rotating dial, triangle, or asterisk), and on digital meters a flow indicator symbol.

Locate your meter now, while there’s no emergency. Note whether the box lid requires a tool. Confirm the meter is yours — in older Portland neighborhoods where multiple accounts are close together, meter boxes can be adjacent. Your meter should be at the property line directly in front of your home.

Step One: The Flow Indicator Test

Turn off every fixture and water-using appliance in the home: all faucets, showers, toilets (stop the fill cycle by flushing and listening until refill completes), dishwasher, washing machine, ice maker, irrigation system. Walk through the home and confirm every fixture is off and quiet.

Go to the meter. Look at the flow indicator: on an analog meter, it’s a small triangular or star-shaped dial near the center of the register face. On a digital meter, look for a drop or wave symbol that appears when flow is detected. If the indicator is moving or the symbol is present with everything shut off, water is flowing through the meter — leaving the system somewhere.

A very slow spin or a brief indicator flash may mean a toilet flapper is leaking slowly. A steady spin or constant indicator means a more significant flow is occurring. This test takes two minutes and is a definitive yes/no on whether you have active water loss.

Step Two: The Volume Test

Write down the meter reading (the number displayed on the register). Wait 30 minutes with nothing running in or outside the home. Don’t use any fixtures, flush any toilets, or run any appliances. Return and read the meter again. If the number changed, water left the system in that 30-minute window.

Multiply the change by 2 for an hourly loss rate, by 48 for a daily loss rate. Portland Water Bureau meters typically read in cubic feet: 1 cubic foot = 7.48 gallons. A meter change of 0.5 cubic feet in 30 minutes means approximately 18 gallons per hour — about 432 gallons per day. That’s a significant hidden leak. A change of 0.05 cubic feet (about 2.5 gallons) in 30 minutes is a slower leak, more consistent with a toilet flapper or dripping fitting.

Step Three: The Isolation Test

This test narrows the leak location to either inside the home or in the underground supply line between the meter and the home.

Go to your interior main shutoff (inside the home near the front wall, in the basement, utility room, or crawl space). Close it fully. Return to the meter and check the flow indicator again. Two outcomes:

Indicator stops: The leak is inside the home — in a supply line, fixture connection, or appliance. With the interior shutoff closed, no water is flowing from the main. The leak is on the house side of that valve. Check toilets, check under sinks, check the water heater connections, check the dishwasher and washing machine supply lines.

Indicator continues: The leak is between the meter and the interior shutoff — the underground supply line from the meter to the home. This is a buried pipe that you can’t inspect visually. Professional detection or excavation is needed. Signs to look for: soft, wet soil between the meter box and the home’s foundation when there’s been no rain, green grass or vegetation growing faster in a specific path from the street to the house.

After the Test: What to Do

If the test confirms water loss and you can’t find the source by checking toilets and visible fixtures, it’s time for professional acoustic leak detection. We use amplified listening equipment to hear water escaping through pipe walls and narrow the location to within inches — before opening any wall or breaking any concrete. Full details on the detection service are at our Portland leak detection page.

If you’re filing with Portland Water Bureau for a leak credit on an abnormally high bill, the volume test results — your before and after readings with timestamps — are useful supporting documentation alongside the plumber’s repair record.