Real-time Performance: The Case of Akaki Phase Liib Well Field
No Thumbnail Available
Date
2020-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
Groundwater is an important source of water supply throughout the world. Its use in irrigation, industries, municipalities, and rural homes continues to increase. There is a tendency to think of groundwater as being the primary water source in arid regions and of surface water in humid regions.
In Addis Ababa for the first time, the modern water supply provision was introduced 15 years after the establishment of the city. At that time the source selected is groundwater and served the city for almost 58 years. At the moment the largest volume of the daily production of water in Addis Ababa is groundwater that accounts for 65% of total daily production.
The vast expansion of the city increases the shortage of water and Addis Ababa Water and Sewerage Authority have implemented the short-term and medium-term plan to overcome the deficit that occurred in the city. The plans implemented are the development of groundwater and the expansion of Legedadi Dam. Even if these projects are functional the shortage of potable water has not yet been solved. Many of the developed groundwater have a failure problem and have shown a decline in the yield. This research, with the help of understanding the real-time performances of the wells, found out the reason for the malfunction and the decline of the yield of the developed groundwater of the Akaki phase IIIB project. The efficiency and the yield of each well were worked out from step drawn down test and the hydraulic parameters were worked out from time draw dawn and recovery test conducted during the well study. These values were compared with values assigned for the welll operation.
From the analysis of this thesis,, many of the wells were failed during the study time. Among 24 wells in the well field, the efficiency obtained for nine wells from the step drawdown test was found to be less than the standard value expected for the production well and it tells that the well failed before construction.
The Transmissivity values of the developed well is also computed by three method using Excel-2013 and the value obtained is compared with the values used during the study and design document and the result tell transmissivity estimates is again found to have errors at design and study.
Description
Keywords
Groundwater, Transmissivity, Akaki phase IIIB, Efficiency, Step drawdown test.