A Realistic Basis for an International Comparison of Real Losses from Public Water-Supply Systems

The paper considers the subject of physical (real) losses from pressurised systems which are used for public water supply. To date, attempted comparisons of leakage management performance between water undertakings world-wide have been severely compromised because there have been no standard methods of defining and calculating real losses. Performance indicators, which have been traditionally used for comparisons, have been too simplistic. Limitations of existing performance indicators are identified in the paper by reference to key factors which should be incorporated in objective comparisons of real losses.
The paper describes an improved methodology which was developed by an International Water Association Task Force, based upon logical concepts using local key parameters, calibrated using auditable assumptions, and tested against twenty-seven diverse sets of data from twenty countries.