Harare City Council Admits Prepaid Water Meters Do Charge For Air, But Insists It’s Not Their Fault

The City of Harare and its partner Helcraw Water have moved to address growing complaints from residents that prepaid water meters are counting air, saying the phenomenon is real but is caused by trapped air in the network and not by a defect in the meters.

In a joint public statement on prepaid water meters and air in water pipelines, the council and Helcraw Water sought to assure residents that prepaid meters operate on the same mechanical principle as conventional meters.

“The only difference is the payment platform; the metering mechanism itself is identical,” the statement reads. “Both prepaid and conventional meters contain a precision-engineered impeller that rotates in response to fluid passing through the meter to measure consumption.”

The City acknowledged, however, that under certain abnormal hydraulic conditions, compressed air travelling through the distribution network can also cause the impeller to rotate, resulting in what it termed “apparent consumption”.

“This phenomenon is associated with the presence of entrapped or pressurised air within the pipeline system, rather than with a defect in the prepaid meter itself,” the partners said.

According to technical investigations cited in the statement, air can enter or become trapped in water mains after pipeline bursts, emergency repairs, pipe replacement works, or during intermittent supply — a common feature in Harare’s water distribution system. It can also occur where automatic air release facilities are absent or inadequate.

When supply is restored, that compressed air is pushed through the network and may pass through customer meters before normal water flow resumes, causing the meter to register usage.

The City said this is not unique to Harare or to prepaid systems.

“There is currently a technological gap in both conventional and prepaid water-meter systems, as existing meters are primarily designed to measure the movement of water through the meter and may not fully distinguish between water flow and significant volumes of pressurised air under abnormal network conditions,” the statement says.

It added that current meters do not measure insignificant quantities of air and remain the best available technology worldwide.

The City and Helcraw Water have urged residents not to leave taps open when only air is coming out.

“Residents are therefore encouraged, whenever they observe only air being discharged from their taps, to close the tap immediately rather than allowing the air to continue flowing,” the statement said.

Residents are also asked to promptly report such incidents to the City of Harare or Helcraw Water so that technical teams can investigate the affected section of the network and safely release the trapped air. This, they said, will help minimise unnecessary meter rotation and improve overall system performance.

As a longer-term fix, the two partners said they are implementing a programme to install combination air valves and pressure relief/air release valves at strategic points across the network.

The devices are specifically designed to expel trapped air during pipeline commissioning, pipe replacement, burst repairs and normal network operation. According to the statement, this will stabilise system pressures, improve hydraulic efficiency, protect water infrastructure and “significantly reduce the occurrence of air-related metering events.”