Application of a hydraulic simulation tool to predict the future performance of water supply systems : case study : Najjembe town water supply system

Abstract

The provision of adequate and reliable water supply to meet both the present and future demand time is becoming a challenge for most water utilities in developing countries. The water supply deficit in Uganda has brought about water governance by application of a range of technical tools to regulate the development and management of water resources and provision of water services, The existence of technical gap regarding the prediction of future performance for water supply systems in Uganda followed by provision of possible improvements in the existing systems formed the basis of this study, This study-aim at predicting the future performance of water supply system with Najjembe town WSS as a case study. The data collection methods included literature and documentary review, land survey programs and participatory methods such as customer survey questionnaire, key informant interviews and observation. The topographical data was obtained using a GPS. The collected data was analysed using Microsoft excel and Water CAD V8i flex tables. The. simulation model for Najjembe town WSS was developed using Water CAD V8i (SELECT series 1) as a simulation tool The study results revealed that. Najjembe town WSS currently has a total safe yield of 115m3/hr. UFW was among the performance indicators studied and It was found to be 3.19%. The Average monthly water supplied by the water utility is 4100.125m3 serving a population of 4,900 people leading to a Per Capita demand, for water of 27.89 L/day. The areas of 'Kasokoso, Ganga, Kabula and Sesse do not completely have access to piped water supply while Nsakya A, Nsakya B and Mubango have access to piped water Pumps currently installed at the WSS have total maximum operating flow of 559.33m3/day, less than the fatal projected future water demand of 90.3:79m3Jday from the start time of the simulation of 0.00 hrs, the water level in the tanks-droppe drastically to 0.2m and the tank became empty from 4010 hrs to 24.00 hrs when the present water system was made. to serve-the future demand thus the future water demand could not be met. It was Concluded that, the town of Najjembe currently has a good distribution system. In place but will not have. capability to serve the whole town in the nearby future of 15 years from present. It was also suggested that either one or more new borehole(s) with safe yield of 627.79 m3/day be drilled to supplement on the existing system and that an additional tank of storage capacity 890 m3 be constructed to Supplement the currently existing twin reservoir.