Performance evaluation of water supply distribution in Kombolcha Town using hydraulic modelling in WaterGEMS

Ethiopia's water utilities, including Kombolcha, face challenges from rising demand, increased consumption, and aging distribution networks. This study evaluates the hydraulic performance of Kombolcha water distribution system, focusing on issues like intermittent supply, low pressure, insufficient velocity, and limited coverage. Using WaterGEMS modelling, key hydraulic parameters of pressure and velocity were analysed during minimum and peak demand periods. Results show over 70% of pressure nodes fall below acceptable levels during peak hours, while only 29% of pipes maintain optimal velocity (0.6-2 m/s) limiting water supply. High velocities exceeding 3 m/s in 12% of pipes during peak demand exacerbate water loss and inefficiency. The system faces a supply gap of 3,536 m3/day and achieving only 75% coverage. Recommendations include adding new water sources, upgrading infrastructure, balancing pressure with valves, and replacing aging pipes. These measures aim to improve performance, reduce water loss, and enhance resilience to growing urban and industrial demands.