Dabus Hydropower Project - Summary
Project Overview
The document presents the pre-feasibility and feasibility study for the Dabus Hydropower Project in Ethiopia, conducted by Studio Ing. G. Pietrangeli S.r.l. for the Ethiopian Ministry of Water, Irrigation and Energy.
Key Components
- Location: Dabus River, a tributary of the Blue Nile in southwestern Ethiopia
- Catchment Area: Approximately 14,400 km²
- Proposed Layout: Cascade with two power plants at different elevations (Ch.0+130 and Ch.0+108)
- Climate: Tropical with mean annual rainfall around 2000mm
Hydrological Study Highlights
| Study Aspect | Methodology | Key Findings |
|---|---|---|
| Data Collection | Hydrometric and meteorological data from multiple stations | Data gaps identified, particularly at Dabus near Assosa station (71% efficiency) |
| Streamflow Analysis | Three approaches: synthetic generation, transfer functions (power-law and ANN), rainfall-runoff modeling | ANN transfer function selected as most reliable (146.4 m³/s average discharge) |
| Flood Frequency | Block maxima approach with EVI, GEV and Log-Normal distributions | EVI (Gumbel) model selected for design purposes despite GEV providing better fit |
Key Technical Findings
- Multi-annual average discharge: ~146 m³/s
- Flow duration curves show perennial character of Dabus river
- Flood analysis based on Didessa station data (more conservative)
- Decreasing trend observed in flood magnitudes over time
Workshop Observations and Responses
| Client Concern | Consultant Response |
|---|---|
| Data quality and completeness issues | Acknowledged, to be addressed in Revision B and Feasibility Study |
| Environmental impact assessment | Baseline study completed, full ESIA to be conducted in next phase |
| Dam safety and construction materials | Preliminary assessment completed, more detailed analysis planned |
Conclusions and Next Steps
The pre-feasibility study provides a solid foundation for the project, identifying key hydrological characteristics and design parameters. The consultant recommends proceeding to the feasibility phase, where more detailed investigations will address:
- Improved topographic data (Pleiades database)
- More comprehensive environmental and social impact assessment
- Detailed engineering design of dam structures
- Refined hydrological modeling