Arjo Dedessa Irrigation Project - Feasibility Study Summary
Project Overview
Project Title: Arjo Dedessa Irrigation Project Feasibility Study Report
Client: Federal Democratic Republic of Ethiopia - Ministry of Water Resources
Date: May 2007
Location: Addis Ababa, Ethiopia
Consultants: Water Works Design & Supervision Enterprise in association with Intercontinental Consultants and Technocrats India Pvt. Ltd.
Report Structure
| Volume | Content |
|---|---|
| Volume I | Survey and Investigation (Annexures 1-3) |
| Volume I(a) | Topographic Survey, Geomorphological Studies & Geological & Geotechnical Investigation (Part I - Report) |
| Volume I(b) | Geological & Geotechnical Investigation (Part II - Appendices) |
| Volume II | Natural Resources (Forestry, Energy & Catchment Development Plan) |
| Volume III | Water Resources (Meteorological, Hydrological, Hydrogeological Studies, Dam & Appurtenant Works, Irrigation & Drainage, Hydraulic Structures) |
| Volume IV | Agriculture (Soil Survey, Land Evaluation, Agricultural Planning, Livestock, Fisheries, etc.) |
| Volume V | Environmental and Socio-Economic Aspects |
Geological & Geotechnical Investigation Appendices
- Appendix A: Bore Hole Logs
- Appendix B: Photographs of Core
- Appendix C: Field Permeability Tests
- Appendix D: Variable Head Test
- Appendix E: Test Pit Log
- Appendix F: Laboratory Test Results
- Appendix G: Geophysical Investigation
- Appendix H: Piezometer Installation Detail
Key Findings from Borehole Logs
The document contains detailed borehole records from multiple locations including:
- Dam axis (left and right banks)
- Original spillway
- Saddle Dam axis
- Quarry site of shell material
Example Borehole Description: "Moderately strong, dark to light grey, with greenish and brownish spots, moderately weathered, slightly fractured and healed, porphyritic TRACHYTE with whitish, greenish and brownish phenocrysts and fillings."
Field Permeability Tests (Lugeon Tests)
The document includes numerous Lugeon test results from various boreholes, showing:
- Test locations and depths
- Water pressure levels
- Flow rates
- Calculated Lugeon values (typically ranging from 2 to 43)
These tests assess the rock mass permeability, which is crucial for dam design and construction.
Variable Head Permeability Tests
Several falling head permeability tests were conducted to determine hydraulic conductivity (K) values, with results typically in the range of 1.50E-04 to 7.47E-04 cm/sec.