Assefa, Birhanu (PhD)Meressa, Mosissa2018-06-182023-11-082018-06-182023-11-082008-07http://etd.aau.edu.et/handle/123456789/1195The city of Addis Ababa is suffering from shortage of water - the city is receiving only 48% of its demand in 2007; at the same time losing 35.73% of its supply in its distribution systems. Financial, management and technical constraints are the main bottlenecks that hamper the city from satisfying the highly growing needs of its residents while loosing such a large amount of treated water within its system. This Masters Thesis focuses on modelling water supply pressure for leakage reduction in the mains of Addis Ababa Water Supply System, especially in Rufael and Saint Paul sub systems. EPANET modelling software prepared by the Environmental Protection Authority of America is used for the purpose. In so doing, first of all water balance at both city and the stated sub-city levels was conducted to visualize the loss of water and for the purpose of indexing the leakage level, at their respective levels. Water supply for the entire city and water consumption as aggregated from individual customer bills was used to evaluate the total water loss at city level and at the sub distribution system levels, respectively. Finally, potential Environmental effects of leakage in the city water supply system are assessed. Quantifying, characterizing and modelling the factors that lead to water leakage in a city water supply system is by its nature a complex task requiring well managed network and reliable data which is scarce in Addis Ababa city water supply system. As a result, cross checking and verification of data was the most significant problem faced during the study. The paper comprises two major parts; namely Leakage Analysis part and Pressure Modelling part. It was found out from leakage analysis part that water leakage in the city was 35.67%. The ILI value was obtained to be 4.74 which is far from an ideal value of 1. Thus, there is a room for AAWSA to target for leakage reduction without affecting the current pressure system. Besides, there is similar room for leakage reduction due to excessive pressure at some nodes with pressure above the recommended maximum for leakage of 80m almost all the day as pointed out from the modelling partenIn Addis Ababa Water SupplyThesis