I FAOISF: 10IETH 71ERIAL ETHIOPIAN GOVairl,riE- UNI-117°D NATIONS SPECIAL FUND PROJZ-CT PORT ON UWE \,(' A H RIME ' GENERAL REPORT UNITED NATIONS SPECIAL FUND ry* FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS REPORT ON SURVEY OF THE AWASH RIVER BASIN Volume I GENERAL REPORT FOOD ANDAGRICULTURE ORGANIZATION OF THE UNITED NATIONS UNITED NATIONS SPECIAL FUND ROME1965 i TABLE OF CONTENTS Page PREFACE 1 CHAPTER I INTRODUCTION AM HISTORICAL ACCOUNT 3 Purpose and Scope of the Project 3 Terms of Reference 3 Arrangements for Execution 4 Kodification of Plan of Operation 6 Summary of Field Work 6 Follow-up Project 7 Training and Fellowships 7 Final Report 7 Acknowledgements 8 Place Names 8 CHAPTER II SUMMARY OF MAIN CONCLUSIONS AND RECOMMENDATIONS 9 A. CONCLUSIONS 9 Description 9 Existing Land Use 9 Resources of Land 9 Resources of Water 10 Prospective Land Use under Development 12 Water Control 13 Priorities in Planning Water Use 15 The Development of Irrigation 16 Estimates of Capital Costs 16 Economic Appraisals 19 B. RECOMMENDATIONS 20 Recommendations 20 Hydrology 20 River Control and Training 20 Soil Surveys 20 Agronomic Studies 20 Cropping Patterns and Rotations 21 Regulation of High-value Crops 21 Fertilisers 21 Irrigation Practices and Water Requirements 21 Irrigation Design and Layout 21 Water Control by Storage Reservoirs 22 Power 22 Methods of Operating Irrigation Schemes 22 Economic and Social Considerations and Priorities 22 Phases and Programs of Development 22 Master Plan 23 Reclamation of Swamps 23 Improvement of Grazing Lands and Range Pastures 23 Watershed Management 23 Health Studies 23 Awash Valley Authority 23 - Page CHAPTER III DESCRIPTION OF THE AWASH BASIN 24 1. Location and Extent of the Basin 24 2. The River 24 3. Physical Features 27 4. Hydrology Factors 28 5. TraditiOnal Climatic Zones 28 6. Population 29 7. Lines of Communication 31 CHAPTER IV OUTLINES OF EXISTING LAND USE 33 1. Patterns of Vegetation 33 2. Agriculture - General 33 3. Crops 33 4. Agriculture in the highlands 36 5. Agriculture in the lowlands 36 6. Land tenure and farming units 37 7. Livestock breeding 37 8. Ranching methods 37 9. Value of grasslands 38 10. Living standards of nomadic tribes 39 11. Production from the land 39 CHAPTER V SOIL SURVEY AND LAND CLASSIFICATION 40 1. Soil Survey - General 40 2. General Reconnaissance of Soils 40 3. Reconnaissance Soil Survey in the Potential Development areas in the lowlands 42 4. Semi-detailed Soil Survey - Selection 43 5. Semi-detailed Soil Survey 44 6. Conclusions 49 CHAPTER VI PROSPECTIVE LAND USE UNDER DEVELOPMENT 50 1. General considerations 50 2. Management 50 3. Crops 51 4. Other factors 52 5. Rotations 53 6. Arboriculture 53 7. Improvement of grazing lands 56 8. Irrigation Water Requirements and Water Quality 56 9. Fertilisers 57 CHAPTER VII CLIMATOLOGY AND HYDROLOGY 58 1. Arrangements 58 2. Climatology 58 3. Regional climates in the Awash Basin 62 4. Hydrology - General 65 5. Analysis of Normal Annual Flows 65 6. Comments on Hydrological Factors 68 7. Flood Characteristics 69 8. Erosion and Sediment Load 69 Page CHAPTER VIII WATER CONTROL FOR IRRIGATION AND POWER 74 Need for Development of Water Resources 74 Storage Dams - General 74 Kesem Dam 75 Kebena Dam 80 Tendaho Dam 81 Meki Diversion Scheme 86 Management of Available Water Resources 89 , 8. Compensation Dam 90 9. Hydro power Potential of the Upper Basin 92 CHAPTER IX PRIORITIES IN PLANNING WATER USE 93 Areas possible 93 Areas possible with various combinations of water control schemes 93 Factors affecting Relative Priorities of Irrigation Development 95 Stages of Development Proposed 96 Master Plan 96 CHAPTER X DEVELOPMENT OF IRRIGATION 98 Present Development 98 Principles affecting the Fxtension of Agricultural Development 96 Individual Irrigation Schemes - Upper Valley 99 Individual Irrigation Schemes - Middle Valley 99 Individual Irrigation Schemes - Lower Plains 100 Stages of Development 101 Comments on Suggested Developments 104 CHAPTER XI ESTIMATES OF COSTS AND ECONOMIC APPRAISALS 105 Estimates of Costs 105 Economic Appraisal 109 Comments on the Economic Feasibility Report 110 Incidence of Settlement 112 Planning of Development 112 Master Plan 112 Awash Valley Authority 113 114 CHAPTER XII ADDITIONAL REMARKS In the lowlands 114 In the High plateau 114 iv - Page APPENDICES I - Plan of Operations - United Nations Special Fund Project in Ethiopia - Survey ofm'the Awash River Basin 116 II - Topography and Mapping 136 III - Feasibility Report on Development of Irrigated Agriculture and Hydl'oelectric Power in the Awash River Basin, Ethiopia 139 BIBLIOGRAPHY 175 LIST OF MAPS AND FIGURES Page 1. General lilap of Ethiopia 5 2. Relief Map of th Awash Basin 25 3. Longitudinal Profile of the Awash Basin ,-)-)- 4. Population in the Awash Basin 30 5. Lines of Comunication and Logistic Layout 32 6. General Map of Soil Survey in the Awash Basin 41 7. Irrigability Map - Middle Valley (in the folder) 8. Irrigability Map - Lower Plains (in the folder) 9. Suggested Crop Rotation Schemes- Middle Valley 54 10. Sug,.;ested Crop Rotation Schemes- Lower Plains 55 11. Climatological and Hydrological Map of the Awash Basin (in the folder) 12. Monthly Flows Recorded at various Gauging Stations 64 13. Normal yearly Distribution of Runoff in the Awash Basin 67 14. Location of works for Water Control 76 15. Sketch Map showing potential Diversion of Meki River 87 16. Asayita Delta suggested Layout and typical Distribution System (in the folder) 17. Schematic Irrigation Layouts - Middle Valley (in the folder) 18. Schematic Irrigation Layouts - Lower Plains (in the folder) 19. Proposed Stages of Development 103 LIST OF TABLES Land Use in the AWalah River Basin 34 Grazing Possibilities of the Grasslands 38 General Soil Reconnaissance 42 Reconnaissance Soil Survey-Suitability for Irrigation 43 Summary Distribution of Soils on the Semi-Detailed soil survey Semi-Detailed Soil Survey - Land Classification for Irrigation 4' Irrigation Water Requirements d. Some Temperatures Observed in1962-64 F0 Awash Basin - Average Annual Temperatures 61 Normal Annual Evaporation Measured by Sunken Tank 62 10a. Normal Annual Evaporation fromaLarge Deep Reservoir 62 Climatic Zones 63 Analysis of Annual Runoff. in "Normal" Year 66 Estimated Maximum Flood Discharge data for various Points along the Awash 70 Awash Basin Sediment Load and Specific Degradation 71 15,Kesem Dam Capacities 77 Regulation of Kesem Reservoir Kesem Dam - Principal Characteristics Kebena Dam - Principal Characteristics 81 Tendaho Dam - Alternative Capacities 82 Tendaho Dam - Evaporation Losses 83 Regulation of Tendaho Reservoir 84 Tendaho Dam - Principal Characteristics 86 Analysis of Awash Flow in Lower Period 90 Compensation Reservoir - Capacities and Area Irrigable Upper Valley - Estimated Power Potential 4 Maximum Areas which could have been irrigated in1962/63 with Various Schemes for Water Control 94 Present and Proposed Stages of Development 96 Proposed Development of Irrigation by Projects and Stages 102 Estimated Costs of Storage Dams 106 Tentative Forecast of Cost of Kebena Dam 107 Estimate of Costs of Diversion of Meki River 107 Irrigation.Development- Particula.rs af lirks and Estima ts of Cost 108 Comparison of Investment Required per Hectare 110 Benefit/Cost Ratios for General and High-Value Crops 111 - vi - GLOSSARY UNITS OF MEASURE METRIC SYSTEM SYMBOLS ( A4. =10-3mm micron ( s; sec second ( ( ( mm =l03m millimetre ( min minute ( ( ( cm =10-2m centimetre h, hr hour metre ( d day m' ( Km = 1,000m kilometre ( °C degree centigrade ( ( cm2 = square centimetre ( cal small calorie ( m2 square metre ( mA miliampere ha = 10,000m2 hectare kV kilovolt ( km2 = 100 ha square kilometre ( kVA kilovolt-ampere ( ( 1 litre ( kW kilowatt ( ( m3 = 1,000 1 cubic metre ( GWh =1,000,000 kWh ( gigawatthour ( hm3 = 1,000,000 m3 ( cubic hectometre ( g gramme ( kg = 1,000g kilogramme = 100kg quintal ( t = 1,000kg metric tOn ETHIOPIAN MEASURES one gasha = 40 ha one massa = 1/40 ha =250m2 one kunna of sorghum, noog= 3.0 kg barley = 4.0 kg beans = 5.5kg wheat, maize, lentils, linseed 6.0 kg peas, guaya, teff or any other product = 5.0 kg one dawula= 20 kunna one Ethiopian Dollar (ES) - 0.40 US Dollar PREFACE The Report on the Survey of the Awash River Basin comprises the following volumes: Volume I General Report Volume II Soils and Agronomy Volume III Climatology and Hydrology Volume IV Water Storage and Power Development Volume V Irrigation and Water Planning These volumes are all issued on the authority of the Special Fund of the United Nations and the Food and Agriculture Organisation. Volume I is a comprehensive Report covering concisely all aspects of the Survey, and setting out the conclusions reached and the recommendations made. It is wholly prepared by FAO. It embraces and is based on the contents of the other volumes. The other volumes were all drafted by the SubContractors, S.O.G.R.E.A.H. of Grenoble, France, who carried out the main work of the Project. They have sub- sequently been edited by FAO. Each of these volumes in its more specialised field provides and analyses the relevant data, discusses the results, and sets out the conclusions to which they point. The discussions in one volume of course in various respects have-reference to and depend upon the discussions in other volumes. The scope of Volume I, as will be seen from the Table of Contents, covers the following: Chapter I Introduction and Historical Account Chapter II Summary of Main Conclusions and Recommendations Chapter III Description of the Awash Basin Chapter IV Outlines of Existing Land Use Chapter V Soil Survey and Land Classification Chapter VI Prospective Land Use under Development Chapter VII Climatology and Hydrology Gnapter VIII Water Control for Irrigation and Power Chapter IX Priorities in Planning Water Use Chapter X Development of Irrigation Chapter XI Estimates of Costs and Economic Appraisals Chapter XII' Additional Remarks 2 It will be realised that Volume I covers the whole work of the Survey, and by itself provides a oomprehensive and coordinated statement of what it has achieved.