A Review of Various Models for Estimating Background Leakage in Water Distribution Networks

Heidari, Bita Sadat; Jalili Ghazizadeh, Mohamad Reza; Moslehi, Iman

doi:10.22112/jwwse.2026.501101.1442

A Review of Various Models for Estimating Background Leakage in Water Distribution Networks

Articles in Press

Document Type : Review Paper

Authors

Bita Sadat Heidari ¹

Mohamad Reza Jalili Ghazizadeh ²

Iman Moslehi ²

¹ Ph. D Student

² Shahid Beheshti University

10.22112/jwwse.2026.501101.1442

Abstract

Leakage in water distribution networks is a major concern due to the considerable losses of water and energy it entails. Leakage is typically divided into three categories: reported, unreported, and background leakage. Background leakage originates from very fine cracks that cannot be detected through conventional leak detection or visual inspection. Because these leaks often remain undetected for extended periods, they can cause significant cumulative water losses. This study aims to provide a comprehensive review of background leakage rate models with respect to pressure and time in water distribution systems. A review of over 50 relevant studies revealed that more than half focused on pressure management as the most effective strategy to reduce background leakage, whereas less than one-third investigated the time-dependent growth of leakage rates. Despite its importance, temporal variation in background leakage has received limited attention in modeling studies, mainly due to challenges in estimating leakage growth rates and the scarcity of reliable data. Accordingly, this research reviews both pressure-based and time-dependent leakage models and discusses how these models can be applied to the analysis and management of water distribution networks.

Keywords

Background leakage, pressure&‌‌‌ndash

leakage, time-dependent leakage, leakage modelling, leakage management