District metering and leak detection

The challenge

A mid-sized system had known for years that it was losing a large share of what it treated. What it did not have was any way to say where. The loss figure was a single number for the whole system, which is enough to worry a board and not enough to spend against.

Two consultants had recommended a mains replacement programme. Both programmes were priced in miles, and neither could say which miles.

What we did

We split the network into district metered areas and instrumented them, then ran night-flow analysis for six weeks. Metering is fundable in its own right, which meant the diagnostic work did not have to come out of the capital budget.

The data put most of the loss in a small part of the network, which changed the project from a programme priced in miles to a job priced in blocks.

The outcome

The replacement scope came down substantially against what had been recommended, and the work that was done could be justified line by line when the state asked.

The district metering stayed in place afterwards, so the next application starts with real numbers instead of another six-week study.

Equipment supplied

• District metered area design and installation
• Magnetic and insertion flow metering with data logging
• Pressure management and control valves
• Night-flow analysis and leak localisation
• Telemetry so the areas keep reporting after the study ends

Figures are from the project file and the award documentation. The customer is not named at their request. Results depend on the site and are not a prediction for any other project.