Water and wastewater treatment agencies are large energy users that operate 24 hours a day. In fact, for many municipalities, water and wastewater treatment can account for as much as 30 to 40% of the energy consumption. However, water and wastewater treatment agencies have not always been encouraged to address the energy efficiency of their facilities. Simultaneously reducing water leaks and improving management practices in utilities can dramatically increase the amount of water available to end users, while yielding significant financial savings. Water and energy efficiency measures repay themselves quickly and the resulting savings in money and water reap many rewards: immediate improvements in water service, increased water delivery, reduced water and energy consumption, and more revenue for system upgrades and new customer connections. Therefore this thesis deals with two of the solutions, improving pumping hours by hybrid power supply system and automating system operation. To do so the thesis deals with the mathematical modeling, design and analysis of a water supply system in Ethiopia- specifically Debre markos town water supply system and tries to implement an automation system using SCADA. Accordingly data about Debre markos water supply system starting from the well field to the distribution and consumption has been collected and analyzed. Then system redesign for pumps, drive motors and generators has been done. Win cap and Willo design software have been used for the redesign. Three cases have been studied for the energy efficiency of the system and production of water as well to optimize power and water, use of grid power only, use of generator only and the hybrid use of grid-generator. Solar pumping system has been accounted. But found to be very costly and in practical. Furthermore, operation automation system using SCADA software IGSS has been designed for the water supply system. The simulation/design/ and analysis results show that Debre markos water supply system can be improved to satisfy the water supply needs of the town to 100% by using the redesigned system.