KPI of the Day – Utilities: % Non revenue water
Measures the total quantity of unbilled water such as water leaked, stolen, used by firefighters, or given for free as a percentage of the total treated water produced.
To assess the extent of water losses from the water distribution network.
Out of the total quantity of water produced and distributed in the water distribution framework, there is a percentage that is lost without being used due to failures and deficiencies in the distribution system, or it is related to non-paying services such as water used by firefighters. This percentage is referred to as % Non-revenue water (% NRW).
Considering the economic costs associated with the distribution of water, the potential revenue as well as an ever-increasing demand for water due to growing population demographics, water utility companies aim at reducing % Non-revenue water as much as possible. Water providers closely monitor % Non-revenue water, along with other indicators of water loss, such as % Unaccounted for water, in order to come up with valuable solutions to conduct cost-efficient operations.
Generally speaking, water loss can be categorized as physical loss, namely water transmission losses or leaks, and overflows in distribution tanks and/or commercial loss, which refers to water used but not paid for. The latter stems from the unauthorized use of water, from metering inaccuracies that imprecisely register consumption or the more obvious process of non-billing metered consumption.
% NRW is strictly related to the actual conditions of the distribution system and the resources the water utility company has decided to direct towards maintenance and control programs. It is maybe unrealistic to think of reducing the costs with water loss to zero, however, initiatives can be taken to reduce it as much as possible.
Some recommendations in this respect can be outlined as follows:
- Implementing a water balance program, as a tool to assess the level of both physical and commercial water losses along with a leakage control system to tackle them;
- Initializing a set of water meter systems, for all water production sources and treatment plants at specific checkpoints;
- Assessing the condition status of production and consumption meters, to reliably report on water flow.