Leak detection that finds loss from the water balance, not the bill.
Aqueduct closes a water balance every minute: metered supply must equal metered use plus loss. Whatever the sub-meters cannot account for is the leak signal, located to a line and an hour.
Supply equals floors, plus fire system, plus RO feed, plus unaccounted loss.
How the balance is built
- Meters at the main and on each line
A smart meter on the incomer and sub-meters on floors, risers, RO feed and process lines. Existing meters join if they send telemetry.
- An equation, refreshed every 60 seconds
The water twin shows Main Supply = All Floors + Fire System + RO Feed + Unaccounted Loss, in gallons per minute.
- Built to the real site
Blocks exist only for what is installed, so a site without an STP or a hot water loop is not modeled as if it had one.
Three patterns in the unaccounted term
- Night flow above baseline
Flow that persists while the building is empty, typical of a running toilet bank or a stuck fill valve.
- A step change
Unaccounted flow that jumps and stays up, pointing to the section where it began.
- A slow climb
Loss that grows week by week, the trace a slab leak or a failing valve tends to leave.
Why the balance is the right test.
of a facility's water use can be lost to leaks.
Source: US EPA WaterSenseunaccounted is the point where EPA says a facility may have leaks. The balance runs that test all day.
Source: EPA WaterSense at Work 2.3An example
Illustrative: a four-floor office closes its balance overnight. Main supply holds at 1.8 gpm while the floors should be idle, and the gap sits between the supply header and the third-floor riser meter. The ticket names that section, attaches the trace and prices the loss with the site's water rate. After a fill valve is replaced, unaccounted flow returns to its night baseline.
Limits
The balance locates loss only as finely as the meters allow: one meter per floor finds the floor, not the fixture. Loss on the utility side of the main meter is outside it.
Legitimate use on an unmetered line, such as irrigation, reads as unaccounted until that line is metered or modeled.
Related
Common questions
A spot leak sensor only reports water where it sits. aQ WaterGuard watches the gap between the main meter and every sub-meter, so it catches loss anywhere in between, including leaks inside walls, under slabs and in toilets that run all night. See burst detection for sudden failures.
Enough to split supply into the areas you want to search separately, such as each floor, riser or process line. Fewer meters still detect a leak but narrow it to a larger area. A site survey maps existing meters and the gaps. See water meters.
Only through a connected motorized valve, where control is enabled, with owner approval. Without a valve, the alert goes to the facilities team with the line and start time, and every command that is sent is logged with whether it executed. See controllers and actuators.
EPA WaterSense guidance says a facility that cannot account for more than a tenth of its water use may have leaks. aQ WaterGuard tracks that unaccounted share every hour instead of once a year, so the search starts when it rises. See the reduce water loss use case.
See Aqueduct on your own facility.
Bring a site, a utility bill or a question. We will show you where the loss is.