Hydraulic Modelling of Water Distribution System of Aksum Town, Ethiopia

Abstract

Intermittent water distribution is the key problem of many water authorities in developing countries including Ethiopia. Hence, this research was conducted to carry out the hydraulic modeling of the Aksum town water distribution system which is located in the Central Tigray region of Ethiopia. The objectives of this research were to evaluate the hydraulic performance of the water supply distribution system by assessing the situation of the existing water supply distribution system. Water GEMS V8i software was used as a tool to model the water distribution system. The model can be used to identify the high pressure and low pressure in the junctions and the magnitude of velocity through pipes was used as a base to evaluate the hydraulic performance. Modeling results showed a violation of maximum and minimum pressure and low-velocity requirements. High pressures in the system occurred both during low demand and peak demand have to be identified. The simulation result of the existing system about 38.6% of the junctions was failed to satisfy the allowable pressure and the velocity of about 34.9% was failed out of range during the peak consumption hour. The model performance measures were checked based on the coefficient of determination. In general, it was concluded that the existing water distribution network systems of Aksum town categorized under satisfactory hydraulic performance situation and were not supply adequate water to various demand categories of the town. In the modified system, the network runs hydraulic parameters are radically improved using the Pressure Reducer Valve added in the system to reduce high-pressure impacts on water distribution system. The results of the simulation show that the hydraulic simulation about 43.4% of pipes of diameter from the total water distribution system pipe diameters needed to be upgraded.