Use a water meter as a record of consumption over a known period. Write down the units and reading time, then distinguish ordinary use from a period intended to have no water use. A change in the reading is information to investigate, not a diagnosis by itself.
EPA WaterSense suggests checking a meter before and after a two-hour period with no water use as one leak investigation step. Follow your utility’s relevant instructions and contact it about results you cannot explain.
Record the reading time and meter units at both ends of the interval. Keeping the entries in one format makes the difference easier to calculate and compare. A brief circumstances note adds the context needed to distinguish ordinary activity from an intended no-use period.
Make a readable log
| Field | Record |
|---|---|
| Meter identity | Confirm you are reading the correct supply |
| Date and time | Both ends of the comparison |
| Units | As shown by the meter or utility guidance |
| Reading | Digits with the same precision each time |
| Circumstances | Known use or the intended no-use conditions |
Keep records from different meters or units labelled separately. The responsible supplier can help confirm meter identity or the appropriate access arrangements.
Check the test conditions
Consider whether an appliance, irrigation system or another household member may have used water during the observation. In a shared building, establish what the meter actually covers. These questions can change the meaning of an apparent discrepancy.
Escalate the unanswered question
Provide the utility or qualified professional with the dated readings and the conditions observed. Avoid assigning a specific leak location or repair from the number alone. Keep billing enquiries separate from physical fault diagnosis: an unexplained bill and an unexplained meter movement may need different checks. This guide does not instruct you to dismantle plumbing or alter the supply.
Calculate a reading difference
For an invented meter showing cubic metres, suppose the first reading is 123.400 and the second is 123.650. The difference is 0.250 cubic metres, equivalent to 250 litres. The reading times determine the period over which that consumption occurred.
Check the units on the actual meter or utility guidance before using this conversion. Record the same meter and precision at both ends, and keep estimated readings labelled if they appear in the utility’s records.
Distinguish normal use from an investigation
A normal-use interval includes the household’s activity. An intended no-use interval asks a different question and needs a note of any known exception. EPA WaterSense describes checking before and after a two-hour period with no water use as one investigation step; follow the relevant utility instructions for the supply.
If a result needs explaining, keep the dates, times, readings and circumstances together. Ask the responsible utility about meter identification, access questions or the appropriate next step. A changed reading supplies an observation, while locating a particular fault needs further assessment.
For ongoing tracking, compare like periods and note major changes in household activity. This helps the log answer a concrete question about consumption while preserving the information needed for a useful enquiry.
A log can include known water use during the interval, along with the readings. If the result needs further investigation, those details give the utility a more useful account of the observation. Keep the relevant utility instructions beside the log for the next check.
Sources consulted
- Fix a Leak Week — U.S. EPA WaterSense; checked 4 November 2026.