The Study on Jarar Valley and Shebele Sub-Basin Water Supply Development Plan, and Emergency Water Supply in the Federal Democratic Republic of Ethiopia
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MINISTRY OF WATER & ENERGY (MoWE) THE FEDERAL DEMOCRATIC REPUBLIC OF ETHIOPIA SOMALI REGIONAL WATER RESOURCES DEVELOPMENT BUREAU THE STUDY ON JARAR VALLEY AND SHEBELE SUB-BASIN WATER SUPPLY DEVELOPMENT PLAN, AND EMERGENCY WATER SUPPLY IN THE FEDERAL DEMOCRATIC REPUBLIC OF ETHIOPIA FINAL REPORT (6/7) SUPPORTING REPORT August 2013 Japan International Cooperation Agency (JICA) Kokusai Kogyo Co., Ltd. The Federal Democratic Republic of Ethiopia Somali Region Location Map of Study Area CONTENTS Location Map Contents List of Tables List of Figures Abbreviations Page: 1 Geophysical Survey ........................................................ 1-1 1.1 Study area and objective of geophysical survey......................................... 1-1 1.1.1 Study area ....................................................................................... 1-1 1.1.2 Objective of geophysical survey..................................................... 1-1 1.2 Survey points .............................................................................................. 1-1 1.2.1 Reasons for selection and number of surveys................................. 1-1 1.2.2 Reconnaissance and selection of prospecting sites......................... 1-2 1.3 Survey method............................................................................................ 1-2 1.3.1 Vertical electric sounding (VES).................................................... 1-2 1.3.2 TEM electro-magnetic sounding (TEM) ........................................ 1-5 1.4 Results of survey and analysis.................................................................. 1-11 1.4.1 VES............................................................................................... 1-11 1.4.2 TEM.............................................................................................. 1-13 1.5 Comparison among VES, TEM and results of drilling ............................ 1-16 1.5.1 Comparison between the TEM and VES results in the Qaaxo-North area................................................................................................ 1-16 1.5.2 Selection of drilling points............................................................ 1-17 1.5.3 Comparison with drilling results................................................... 1-18 1.6 Hydrogeological interpretation by the results of geophysical survey ...... 1-19 1.6.1 Qaaxo-North area.......................................................................... 1-19 1.6.2 Qaaxo-South area.......................................................................... 1-20 1.6.3 Qaaxo-East area ............................................................................ 1-21 2 Well Drilling and Pumping Test ....................................... 2-1 2.1 Purpose and methodology of well drilling ................................................. 2-1 2.1.1 Purpose............................................................................................ 2-1 2.1.2 Methodology................................................................................... 2-2 2.2 Selection of drilling sites ............................................................................ 2-3 2.3 Results of well drilling ............................................................................... 2-6 2.3.1 Summary of drilling work............................................................... 2-6 2.3.2 Lithological conditions ................................................................... 2-6 2.3.3 Results of geophysical logging..................................................... 2-11 2.3.4 Correlation of results between drilling and geophysical survey... 2-13 2.4 Pumping test ............................................................................................. 2-15 2.4.1 Introduction................................................................................... 2-15 2.4.2 Step-drawdown test....................................................................... 2-15 i 2.4.3 Continuous test ............................................................................. 2-20 2.4.4 Recovery test................................................................................. 2-23 2.4.5 Conclusion of pumping test .......................................................... 2-24 2.5 Hydrogeological aspects and prospects.................................................... 2-25 3 Socio-Economic Survey .................................................. 3-1 3.1 General........................................................................................................ 3-1 3.2 Development plan and related Laws .......................................................... 3-2 3.2.1 National level (Federal Ethiopia).................................................... 3-2 3.2.2 Somali region.................................................................................. 3-3 3.3 Socio-economic conditions in the Region.................................................. 3-4 3.3.1 Population and demographic characteristics................................... 3-4 3.3.2 Local administrative divisions........................................................ 3-6 3.3.3 Regional economy .......................................................................... 3-6 3.4 Refugee conditions in the Somali Region .................................................. 3-6 3.5 Analysis of socio-economic survey............................................................ 3-8 3.5.1 Water use survey............................................................................. 3-8 3.5.2 Survey on woreda water supply situation..................................... 3-13 3.5.3 Survey on urban water supply system .......................................... 3-19 4 Environmental and Social Consideration ........................ 4-1 4.1 Title of the project ...................................................................................... 4-1 4.2 Name of the proponent ............................................................................... 4-1 4.2.1 Responsible organization................................................................ 4-1 4.2.2 Implementing organization............................................................. 4-1 4.3 Introduction of the project .......................................................................... 4-1 4.3.1 Introduction..................................................................................... 4-1 4.3.2 Background..................................................................................... 4-2 4.3.3 Outline of the project components.................................................. 4-2 4.4 Outline of the water supply plan................................................................. 4-4 4.4.1 Urban water supply plan................................................................. 4-4 4.4.2 Rural water supply plan .................................................................. 4-7 4.5 Environmental and social categorization.................................................... 4-8 4.5.1 Categorization................................................................................. 4-8 4.5.2 Account........................................................................................... 4-8 4.6 Location of the project.............................................................................. 4-10 4.6.1 Project site..................................................................................... 4-10 4.6.2 Social conditions........................................................................... 4-10 4.6.3 Natural environment ..................................................................... 4-16 4.6.4 Environmental pollution ............................................................... 4-19 4.7 Alternatives (zero option case)................................................................. 4-21 4.8 Results of environmental and social impact assessment .......................... 4-22 4.9 Mitigation ................................................................................................. 4-26 ii 4.10 Conclusion................................................................................................ 4-27 ANNEX ANNEX 1 Minutes of Meeting M/M-0 Minutes of Meeting on Inception Report M/M-1 Minutes of Meeting on First Steering Committee M/M-2 Minutes of Meeting on Second Steering Committee M/M-3 Minutes of Meeting on Third Steering Committee ANNEX 2 Confirmation Letter K-1 Confirmation Letter on the Supply and Management of the Equipment and Facilities for the Pilot Project in Kabribeyah Town iii List of Tables Page: Table 1.1: Number of Geophysical Survey ................................................................... 1-1 Table 1.2: Types of Geophysical Survey in Each Area................................................. 1-1 Table 1.3: Schlumberger Electrode Spacing ................................................................. 1-3 Table 1.4: Specs of the Electrical Survey Instrument ................................................... 1-3 Table 1.5: TEM Measuring System............................................................................... 1-7 Table 1.6: Sampling Schedule for the Transmitter........................................................ 1-7 Table 1.7: Classification of Resistivity Values ........................................................... 1-13 Table 1.8: Comparison between Geology and Geophysical Survey Results in Drilling Sites ........................................................................................................