Geremew SahiluGeatachew Welay2025-03-052025-03-052024-11https://etd.aau.edu.et/handle/123456789/4467Problems in providing satisfactory water supply to the rapidly growing population especially that of the developing countries is increasing from time to time. The objective of this research was to assess the problem of Addis Ababa Lideta sub city water supply and distribution network system. This study assessed the hydraulic performance of Lideta sub city water supply distribution network system based on main performance indicators namely high-water loss, inadequate water supply coverage, satisfaction of customers and low operation and maintenance. Intermittent water distribution is the key problem of many water authorities in developing countries including Ethiopia. Hence, this research was conducted to carry out the hydraulic modeling of the lideta sub city water distribution system which is located in the center of Addis Ababa city of Ethiopia. The objectives of this research were to evaluate the hydraulic performance of the water supply distribution system by assessing the situation of the existing water supply distribution system. Water GEMS V8i software was used as a tool to model the water distribution system. The model can be used to identify the high pressure and low pressure in the junctions and the magnitude of velocity through pipes was used as a base to evaluate the hydraulic performance. Modeling results showed a violation of maximum and minimum pressure and low velocity requirements. High pressures in the system occurred both during low demand and peak demand have to be identified. The simulation result of the existing system about 88.78% of the junctions was failed to satisfy the allowable pressure and the velocity of about 40.36% was failed out of range during the peak consumption hour. The model performance measures were checked based on the coefficient of determination. In general, it was concluded that the existing water distribution network systems of lideta sub city categorized under satisfactory hydraulic performance situation and were not supply adequate water to various demand categories of the town. In the modified system, the network runs hydraulic parameters are radically improved using the Pressure Reducer Valve added in the system to reduce high pressure impacts as well as added new water sources wells around the area on water distribution system. The results of the simulation show that the hydraulic simulation about 53.4% of pipes of diameter from the total water distribution system pipe diameters needed to be upgraded.en-USNew Water Demand CentersWater Supply Distribution NetworkWater GEMS V8i ModelPopulation DensificationCondominium Houses & Hydraulic Performance.Thesis