This document provides a methodology for undertaking a water loss investigation and establishing general principles for water loss management in drinking water distribution networks in order to improve the sustainability of drinking water utilities and protect the environment by saving water, energy and use of chemicals.


This document establishes a procedure to estimate water loss components through water balance calculations and to define general principles of water loss management. This document deals with the preparation of a water loss management plan for water loss reduction and management projects but does not cover its execution.


This document does not cover bulk drinking water supply systems, but can relate to pumping, storage and transmission within the drinking water distribution network.


This document can be used analogously for non-public supply systems, raw water and industrial water systems.


This document is intended for drinking water utilities and other stakeholders.