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How to Check for a Water Leak With Your Water Meter
- Last reviewed: October 13, 2026
Turn off every water use in the house, read the meter, wait, and read it again: if the numbers changed, water is leaking somewhere. The test takes a few minutes of work plus a waiting period, and it tells you whether a leak exists before you pay anyone to look for it.
This guide pairs EPA's method with Castle Rock Water's meter guidance.
Before you start: find the meter
Castle Rock Water says your meter is typically located inside your home in the basement or crawl space, though some homes have a meter pit outside. If yours is inside, the test is straightforward. If it sits in an outdoor pit, read the caution below before touching anything.
The two-hour test
- Stop all water use. Close taps, dishwasher, washing machine and shower. Pause anything that fills on a timer, such as an ice maker, humidifier or irrigation controller.
- Read the meter. Write down the numeric display and note whether any flow indicator is moving. Castle Rock Water says that if the meter has a flow indicator that moves or a numeric display that increases, water is flowing through the meter.
- Wait. EPA describes checking the meter before and after a two-hour period with no water use. Castle Rock Water's own wording is to record the reading and check again several hours later.
- Read it again. Any change means water used something while you were not using it.
For a quicker first check, look at the flow indicator right after step 1. If it is moving, you do not need to wait.
What the result means
What you see
What it likely means
What to do
What you see
No change and no moving indicator
What it likely means
No leak found on the house side of the meter during the test
What to do
Check toilets with food coloring; watch the bill
What you see
Reading changed
What it likely means
Water is escaping somewhere, or a hidden use cycled on
What to do
Repeat the test with the main shut-off closed
What you see
Stops moving once the main shut-off is closed
What it likely means
The leak is inside the house or at a fixture
What to do
What you see
Still changes with the main shut-off closed
What it likely means
The leak is between the meter and the shut-off
What to do
Contact us or Castle Rock Water
The last two rows depend on where your shut-off sits relative to your meter. Castle Rock Water tells customers who suspect a leak to turn off the main water valve near the meter, which is the same shut-off used in this test.
Rule out the toilets first
Toilets are a common silent loss. EPA suggests adding food coloring to the tank, and if any color shows up in the bowl after 10 minutes, you have a leak. Flush afterward so the dye does not stain the tank.
If the leak is outside
When the meter moves and the toilets pass, the water may be leaking outdoors: in the sprinkler zones, in a hose bib, or in the line from the meter to the house. Sprinkler systems can be tested on their own by shutting off the irrigation supply and repeating the meter check. A leak in the line itself is the job of underground main line leak detection.
Cautions for Castle Rock homes
- Do not open an outdoor meter pit in cold weather. Castle Rock Water warns that opening it allows warm air to escape and the colder air in, which can cause pipes to freeze. The same page says not to access or tamper with the pit and notes that pits are often inhabited by black widow spiders and other critters.
- Keep the meter clear. Do not stack boxes or furniture in front of it.
- The meter belongs to the Town of Castle Rock. Do not remove or tamper with it. For meter help, call Castle Rock Water at 720-733-6000.
- Pit meters can be checked for you. Castle Rock Water offers a flow detection service call with a technician if your meter is in a pit or you have questions.
When the test says leak but you can't find it
A moving meter confirms there is a leak but not where. Locating the source before any wall, floor or yard is opened is the job of hidden water leak detection.
FAQs
How long should I wait before the second reading?
EPA uses two hours. Castle Rock Water says several hours. Longer waits show small leaks more clearly.
Can a meter move even if I have no leak?
Yes, if an ice maker, softener, irrigation controller or toilet refill cycled on. Pause those and repeat.
Does a still meter prove I have no leak?
It shows no flow during the test window. An intermittent leak or one on the sewer side may not appear, so repeat the test if the bill stays high.
When does Castle Rock read meters?
In the first three days of every month.
Think you have a hidden leak?
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