HYDRAULIC PERFORMANCE ASSESSMENT OF BOKU-MOYALE TOWN WATER SUPPLY SCHEME USING WATERGEMS SOFTWARE, OROMIA REGIONAL STATE, ETHIOPIA

Abstract

Water is an essential element required for the sustenance of life. Demand for drinking water is increasing on continual basis with corresponding increase in population. This study focused on the water supply system of Boku-Moyale town, second town of Borena Zone, Oromia Regional State of Ethiopia. The objective of this study is to assess the hydraulic performance of existing water distribution system of the Boku-Moyale town scheme which is aimed to help the town understand its distribution system needs and assist them in long-term planning of water assets. The scope of the study is to evaluate the hydraulic performance of the existing water distribution system using Water GEMS model and recommends the possible remedies to improve the efficiency of the existing system. The hydraulic models or simulation software used for this study is Water GEMS V8i distributed by Bentley Systems. Water GEMS V8i was selected due to versatile, compatibility and Darwin optimization as compared to Water CAD V8i. This research is both the quantitative and qualitative type. The study was also focused on increasing hydraulic reliability and optimizing the system resource. To achieve the goal legion tasks were carried on. The water demand requirement in the study area was estimated based on water demand categories duty factor and historical water consumption approaches. ArcGIS based tools was applied for digitizing Village of the town mapping and system layout map. Moreover, to analyze the existing water distribution system, a model was developed by using Water GEMS V8i. The model can be used to identify the zone of high pressure, low pressure in junctions and the level of velocity through pipe, which have negative effects on the performance of the network system. As a result, over and under sized pipes have been re-sized and ages Pipes more than 20 years are replaced. Consequently, the Hazen Williams C-value has been totally improved and it enhances the system performance. In addition, from five years obtain data of production and consumption the average loss become 35 % and the modified distribution network was observed to improve the minimum and maximum water flow velocity through providing appropriate pressure in the ranges of 9-80 m H20. It has been noticed that maximum pressure criteria violation percent was increased 20 percent in night flow and during minimum flow hours it also reduced from 30 percent to 5 percent during peak flow. The study concluded that the existing water distribution network in the study area was not adequate to satisfy the required water demand. Assessed the system network and possible corrections are given for Optimum water supply network even using Darwin Optimum Pipe Network Designer tool so as to at least the system meet the required design criterion as a constraints