This document provides a methodology to evaluate the water demand to develop a master plan for water supply. This document establishes general principles to consider relevant data of existing and future systems in the context of climate change and other structural factors, such as social behaviour and urban or industrial developments. It reviews the following:

• description of the water supply system;
• water balance regarding resources and demand;
• change of resource and demand in future (e.g. impact of climate change);
• water loss situation;
• maximum peak factors in present and future;
• emergency supply;
• conditions of infrastructure;
• digitalisation of infrastructure;
• recommendation for optimization.