Sustainability Assessment of Urban Water Distribution System a Case of Bahir Dar City Ethiopia
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Date
2021-10-11
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Addis Ababa University
Abstract
One of the most fundamental requirements of human life is water. As a result, everybody should have access to adequate and safe water on a continuous basis. For adequate and safe water supply, proper design and execution of the new distribution and the operation of the existing distribution network is needed. The study aimed to assess the sustainability of Bahir Dar City's pressure zone-1 water supply distribution system. For assessing the hydraulic sustainability, an analytical model (WaterGEMS V8i) was used to model the WDN and produce hydraulic parameters (velocity and pressure). Sustainability indicators (reliability, resilience, and vulnerability) were calculated based on these parameters and used to determine the sustainability index. The WaternetGEN tool was used to assess the distribution network's hydraulic performance. A geographic positioning system (GPS) and Arc GIS 10.4.1 was used to check the existing layout and to generate the study area. The results showed that; the distribution system has overall sustainability indexes of 0.71 for the current peak hour demand, with sustainability indexes of 0.97 and 0.43 for pressure and velocity, respectively. Based on the result of this analysis the distribution network sustainability is acceptable for current demand. However, the overall sustainable indexes for forecasted demand has been reduced to 0.32, which is in the medium range but unacceptable. It is found that also Pressure in a WDN had a technical performance index of 86.53 %, while the performance indexes of velocity in the distribution system is 57.86% after optimization of the hydraulic parameters in WDN. Water age was determined at low demand hour. Analysis for water age was based on assumption that the distribution system was loaded with continuous flow. The maximum water age in the distribution system is 19.93 hour which is less than a day and acceptable. In general, the result of this study showed that the current distribution network is sustainable for the current water demand.
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Keywords
Sustainability Assessment, Sustainability & Performance Indexes, Watergems V8i, Water Distribution Networks, Waternetgen Tools