Non - Revenue Water

Water supply systems worldwide are generally designed to provide water to consumers at some agreed level of service, which is often defined as a minimum level of pressure at the critical point: the point of lowest pressure in the system. In addition, there may be certain fire-flow requirements that can override normal consumer requirements. The systems are designed to accommodate these pressures and flow requirements during the period of peak demand, which would normally occur at a specific time of day and during a particular month in the year. In other words, the systems are designed to provide the appropriate supply volumes and pressure during a very short period in the year and for the remainder of the time the systems tend to operate at pressures that are significantly higher than required. Even within the same system, there will be areas of high pressure owing to topography and/or distance from the supply point, with the result that many parts of a supply area will operate at pressures significantly higher than required in order to ensure that there is sufficient pressure at the one critical point.

Managing water pressures in a supply area is not a simple issue and there are a great many aspects to consider. The common factor in every system is the fact that leakage is driven by pressure, and if the pressure is increased the leakage will also increase. If the water pressure in a system can be reduced, even for a short period during times of low demand, the water leakage from the system will be reduced.

Advanced Pressure Management is an advanced system which continuously adjusts and controls the pressure of water going into a District Metering Area so that under all demand characteristics, where the critical point (CP) is kept to specified client charter, consistent with good service which gives pressure and flow data to be collected thru telemetry. It is then used as a decision support tool which allows hydraulic analysis such as Minimum Night Flow (MNF) and flow factor profiles to be analysed. This enables swift intervention with active leakage control is economically justified.