KPI of the Day – Utilities: % Unaccounted for water (UFW)
Measures the percentage of the water lost, because of leakages, wastage, mechanical errors in meters at the source, or human errors in correctly recording the meter reader, out of the total treated water produced.
To monitor the effectiveness of water distribution and maintenance.
A commonly known fact in the water utilities industry: not the entire quantity of water that flows through the distribution network ends up at its destination. There is a certain amount of water which is lost due to failures and deficiencies in the distribution system. By monitoring the % Unaccounted for water, utilities companies aim at controlling and mitigating potential water losses.
% Unaccounted for water includes underground leakage, unauthorized use, unavoidable leakage, inaccurate master, industrial, commercial and domestic meters and unusual causes. It results from poor maintenance and it can be reduced by effective maintenance.
Generally, water loss can be regarded as physical loss, because of pipe breaks, leaks or overflows in the distribution tanks. It can also be regarded as a commercial loss, when it is used but not paid for. The latter stems from the unauthorized use of water from metering inaccuracies that imprecisely register consumption and can sometimes be the after effect of a mere non-billing of the metered consumption.
% UFW is strictly related to the actual conditions of the distribution system as well as the investment that the water utility company decides to direct towards maintenance and control programs. It may be near to impossible to reduce the associated costs of water loss to zero, but initiatives can be taken in order to prevent instances of high values in % Unaccounted for water.
Here are a few that you can apply in your company:
- Water balance programs to assess current levels of water losses, enable active leakage control systems and pipe replacement programs;
- Replacement plans to include pressure reduction and corrosion control;
- Metering testing systems for production sources and meters for multiple check points in the distribution network;
- Maintenance of both production and consumption meters to ensure reliability of water flow measurements.