Water losses on any given supply system increase over time due to infrastructure deterioration, meter under-reading/failure, non-authorized consumption etc.
To quantify and understand the level of water loss occurring on a supply network it is necessary to undertake a water balance or minimum night flow (MNF) test. Daily demand levels on a network increase and decrease depending on the time of day but, generally speaking, levels of demand between the hours of 00:00 & 05:00 are at a minimum. It is therefore necessary to monitor and record flows during these hours to get a true representation of a network’s level of water loss. The following image is of a typical daily cycle of water consumption: