From single-leak to network-scale modelling of background leakages for asset management

The framework integrates the physically based Fixed Area and Variable Area Discharge (FAVAD) model and the empirical POWER formulation within a pressure-driven analysis context, establishing their equivalence through physically interpretable crack- and asset-state indicators.

The proposed formulation extends leakage representation from individual cracks to networks and district-metered areas while preserving consistency between pressure-dependent leakage behaviour, pipe deterioration and material response. Within this framework, the asset management support indicator (AMSI) is reinterpreted as a physically based pressure-normalized leakage indicator. Application to a real water distribution network shows that substantially different assumptions on deterioration and material stiffness produce nearly indistinguishable hydraulic responses, highlighting structural limitations in leakage-model calibration based solely on hydraulic observations.</p>