PERFORMANCE EVALUATION OF URBAN WATER SUPPLY SYSTEM; A CASE OF JIGJIGA TOWN, SOMALI REGIONAL STATE, ETHIOPIA

Abstract

In most developing countries, such as Ethiopia, problems with urban water supply and demand are common. The purpose of this thesis was to assess the present urban water delivery system in Jigjiga Town with the major goals of identifying issues with the Jigjiga Town water system by evaluating the current status of the town's water supply system, evaluating the WSS hydraulic performance, and finally propose corrective solutions. The present situation was assessed using the gap between the town's supply and demand by forecasting its population, while water losses were calculated using the difference between production and consumption data. In addition, WaterGEMS software was utilized to construct the model in order to examine the current water supply and distribution system. The model was used to adjust the high and low-pressure zones at junctions, as well as the velocity through the pipe. To explore the system model, the model was run for steady-state simulation and extended period simulation. According to the results of the research, the Town's water supply just covers 64% of demand. This result indicates the prevalence of demand-supply gap. Furthermore, the average loss from three years of production and consumption observation was 36 %. Moreover, the system has issues of over and under pressure, with utmost pressure occurring at extended period simulation (EPS) at PHD being 69mH2O, which is under the suggested range, and 83.5 % (182 points) of the velocity in the pipes being less than 0.5m/s. To deal with these issues, additional pumps must be installed to enhance production, existing well sources must be rehabilitated, and the capacity of the distribution pipeline must be increased by installing new pipes