Access to clean water is often taken for granted, just like the fresh air we breathe. We forget that clean water is a product, and that producing enough is actually a comprehensive, detailed process.
And resources are scarce. By adding inadequate distribution management, we are faced with a more invisible, yet crucial problem: water loss, and in addition to this, non-revenue water (NRW).
Non-revenue water 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.
A World Bank study puts the global estimate of physical water losses at 32 billion cubic meters each year, half of which occurs in developing countries. Could these water losses be halved, it would be enough to supply around 90 million people.
The reasons for water losses are many, ranging from leakages, pipe bursts, and poor water management to illegal connections and unauthorised consumption. But luckily, so are the available solutions - and their benefits.
Operating a water distribution network is no easy task. A network often covers an extensive area and a complex, hidden system of pipes, making it difficult to detect changes, damages or illegal connections. Managing water losses or non-revenue water in an open system would then also mean working in a reactive, passive manner, where activities are initiated only when a loss becomes visible or is reported.
Dividing the network and focusing efforts
Therefore, dividing the supply network into smaller sections - district metering areas (DMA) - is a more efficient technique; it is then possible to calculate water losses individually, and operators are able to better plan and prioritise their efforts.
Leakages can easily be detected through noise loggers integrated in ground-level surface boxes, enabling operators to set in exactly when and where needed. This secures quick repair, meaning less water lost and a minimum disturbance of the network customers.
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 %.
By using DMAs, it is also possible to measure and manage the water pressure in the different areas of the water supply network.
Learn more about pressure management, and how this is helpful in reducing NRW levels.