In water supply systems, the power cost is one of the most important components in which large amounts of energy are required for production, pumping, transportation, and distribute the water in the networks. The water supply systems are the most important public utility for safe supply of potable water. Energy consumption in water supply system represents a major concern in the Sultanate of Oman. This paper discusses several studies and actions have been done in water operational assets to reduce and optimize the power consumption. The public authority for Water in Oman (Diam) has implemented many successful energy optimization methodologies and tools in desalination plants, pumping stations, wells and water distribution networks such as energy recovery devices, variable frequency drivers, pumps overhauling, rescheduling of pumping times, bypassing the pumping stations, maintenance of wells.