Water distribution systems are designed to fulfill all requirements of potable water neededrnfor decades. Initial system designs frequently consider any anticipated changes likely tornhappen. However, as time elapsed they slowly begin to fail to satisfy customersâ€™rnrequirements. Adama town is the capital city of Oromia regional state. It is also one of thernlargest city of the region as well as the country with a total population of around 547,987.rnThe main objective of this study was to investigate the state of the existing waterrndistribution system and evaluate the hydraulic performance of the water distributionrnnetwork with the aid of computer analysis. The peak hour demand was analyzed to verifyrnthat the existing sizes of network pipes are sufficiently provide the minimum requiredrnpressure at all demand points. The minimum hour demand was analyzed for evaluation ofrnpipe material and strength of the network. rnTo evaluate the existing performance of water distribution system, a model was developedrnutilizing Water CAD software. The model can be used to solve ongoing problems, analyzernproposed operational changes, and prepare for unusual events. Calibration of data onrnpressure at different location were collected. The model run was performed for differentrnscenarios to analyze the system model, what if conditions. These scenarios are at averagernday demand, peak hourly demand and Minimum day demand. Comparing representativernsamples of the distribution mainâ€™s pressure field-test with the model-simulated valuesrnshowed a reasonable and small difference to calibrate the model. The model analysis resultrnshowed the different problems of the system, these are oversized and undersized pipes,rnzero flow velocity and low pressures (negative 87m up to 9m H2O) due to pipe size andrntopography of the area.