Evaluating Hydraulic Performance Of Urban Water Supply Distribution System: A Case Study Of Debre Markos, East Gojjam Zone, Amhara Regional State, Ethiopia

Abstract

Water supply distribution systems are facing challenges to deliver quality and adequate quantity of water with the require velocity and pressure. These challenges come from rapid population growth, migration to urban cities, scarce water resource, poor design, poor operation and poor maintenance of the system. These also expose infrastructural decay, inefficient distribution system and water demands on pipeline increasing every day. Debre Markos town, which is found in East Gojjam zone Amhara Region, is rapidly grown commercial town. To assure this growth a potable, reliable and adequate quantity of water supply is needed. Then evaluating the hydraulic performance of water supply distribution system of the town was paramount importance to upgrade the distribution system or add new resource to meet current and future demand. The main objective of this research was to evaluate hydraulic performance of water distribution system based on widely accepted key standard. Evaluating hydraulic performance of water distribution system is useful to identify the gap between supply and demand, as well as the deficiency of hydraulic parameters in water supply distribution system. Primary and secondary data were collected. Hydraulic network Simulation with Bentley WaterCAD was carried out to track water supply, water demand, flow velocity and pressure at each node. Both single and extended period simulation were carried out. According to the research result, the following were found. Debre Markos population in 2011, 2012, 2013, 2014 and 2015 was 70910,73959,77140,80457 and 83916 respectively. Debre Markos town was exposed for sever water shortage in 2011-2015. Because of supply (l/p/d) of each year were below unit demand (20l/s). Water loss (percentage) in 2011-2015 was 14.4, 17.5, 19.4, 29.6, and 24.2 respectively. During steady state simulation water supply failed to meet nodal demand. Moreover, at extend period pressures at 39 out of 69 junctions were higher than recommended pressure (60m) and the flow velocity 78 out of 97 links were below minimum allowance velocity (0.6m/s).