Background Water Supply Systems (WSS) are large-scale systems that collect, store, treat and transport water over wide geographical areas to consumers. Safe and efficient operation is crucial for these systems. WSS can have major environmental impacts due to the substantial amounts of energy consumed, as well as through the emission of greenhouse gases (GHG) and water leakages. This means that saving water will necessarily save energy. Current control systems are designed to deliver water, not to provide water efficiently. Moreover, water network management still relies on the utilities’ accumulated experience, rather than on efficiency technologies. Water utilities face a double challenge to simultaneously save water and energy. This is particularly relevant in the WSS sector, where energy is mostly generated from non-renewable sources. Objectives The LIFE SWSS project aims to demonstrate and disseminate an innovative management and decision-support platform for water supply systems (called a Smart Water Supply System: SWSS). The SWSS platform will be composed of five modules: Predictive, Hydraulic simulation, Assessment, Leakage, and Optimisation, which together will support the water companies in their efforts to improve energy efficiency and water efficiency. The SWSS modules are based on previous developments from consortium partners of the project, which will be integrated into one single platform. The project will be implemented on three demonstration water supply systems (AdA, AdC and AdO) under real working conditions. In these three demonstration WSS, the objectives are to reduce energy consumption, GHG emissions and water leakage by implementing the SWSS platform and the reverse-pump for energy recovery (renewable energy) in gravity systems. Expected results: Energy consumption: reduction of 15% in the energy consumption of each demonstration systems: 0.75 GWh in AdA; 0.45GWh in AdC; 1.35 GWh in AdO (2.6 GWh in total); CO2 emissions: reduction of 15% in CO2 emissions for each demonstration systems: 354 tonnes CO2 eq in AdA, 252 tonnes CO2 eq in AdC; 637 tonnes CO2 eq in AdO (1.243 tonnes CO2 eq in total); and Water losses: reduction in average water losses in the three supply systems from 2.6% to 1%.