Proposed Methodology

A good management of water losses depends not only on identifying rehabilitation and improvement priorities for the distribution network , but equally on the introduction of effective methods and practices for assessing, monitoring and controlling of the main elements of non revenue water (NRW): real losses, apparent losses and unbilled consumption.
 
For a performant management of water losses it is proposed to include in current practices modern methods and tools for monitoring analysis, such as Water Balance and Infrastructure Leakage Indexes.

The water balance is based on actual measurements or estimates, using the best and most reliable information available. Once the volume of NRW is established it is necessary to break it down into apparent losses and real losses as indicated in the table.
 
Further on, Performance Indicators can be developed, as mentioned below, that can be linked to infrastructure performance criteria to guide network rehabilitation needs.