Non-revenue water (NRW) is basically produced, cleaned water which is lost somewhere in the water distribution system, never reaching its final destination. This means water not used or paid for, affecting local economies as well as local resources available. The problem is universal, ranging from NRW levels of about 5% to as much as 80% in certain areas.
To reduce the non-revenue water level, we need to make sure that as much water as possible stays within the network. But why is water even lost, and what are the options available?
10 steps to reduce water loss and non-revenue water:
1. Aim for efficient leakage recovery
Leaking pipes and equipment, due to bursts or breaks, is one of the primary causes to water loss. When a leak occurs, it can take days, weeks or even years before it is noticed, and localising the exact area in a huge, wide-reaching network is no easy task.
2. Divide the water network into sections
Trying to cope with water losses in the complete distribution network at once would therefore also mean working in a reactive, passive manner, where activities are initiated only when a loss becomes visible or is reported.
Therefore, dividing the supply network into separate sections, also referred to as district metering areas (DMA), is an efficient technique that makes it possible to obtain a valuable overview of what is going on below the ground. Water losses can then be calculated in the sections individually, and operators are able to better plan and prioritise their efforts.
3. Quick assessment and repair
Through this separation of the network, operators can act more efficiently and target issues immediately. With quick assessment, vital resources are saved, and network activities are faster up and running, causing less disturbance for all the network customers depending on a continuous supply of water.
By investing in a targeted leak detection program, it is in most places possible to reduce the overall leakage in the distribution system by at least 40–50%.
4. Monitor network activities
Leakages can easily be detected through noise loggers integrated in for example ground-level surface boxes. The loggers react to the sound of leaking water and enable operators to set in exactly when and where needed.
By using the technique of district metering areas, it is also possible to measure and manage water pressure in the different areas of the water supply network.
5. Take control of the network pressure
Pressure management is considered the single most beneficial, important, and cost-effective leakage management activity. The higher the pressure, the more water lost through bursts or leakages. Furthermore, most pipe bursts occur not only because of high pressure, but rather due to ongoing pressure fluctuations forcing the pipes to continuously expand and contract, resulting in stress fractures.
For pressure management, control valves are essential. Control valves are regulating valves, able to maintain certain pressure, flow or level regardless of changes in the supply network. Therefore, they can assist in reducing water losses while upholding the best conditions for the network equipment.
Pressure management is also an efficient way of reducing unnecessary energy consumption. By allowing for a lower pressure in general, especially during off-peak hours, energy consumption for pumping can be reduced. The pressure can be adjusted to the critical point at a strategical consumer in the DMA, which means that no energy will be used to pump water to a higher level than necessary.
Learn more about pressure management here, or through the download links below.
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The LEAKman Project
LEAKman offers water suppliers one integrated leakage management solution to bring down non-revenue water levels; less than 20% within the first year.Go to leakman.net