Consulting Engineers

WATER SUPPLY STUDY AND DESIGN, AWARENESS CREATION AND CATCHMENT REHABILITATION FOR GEFFERSA, LEGEDADI AND DIRE CATCHMENT AREAS IN ETHIOPIA

The consultant’s scope of service was mainly divided into 6 components. These included:

  1. Review of the master plan of the catchments. Reassessment of water resources potential and water management options.
  2. Identification of stakeholders and clearly show the positive and negative impacts of the project on the stakeholders through effective consultations with each group of stakeholders that is well documented.
  3. Conduct the awareness creation and design training mechanisms for the population in the catchments, stakeholders & collaborators and the AAWSA staffs in the responsible Department & the Management respectively. The population in both the three catchments and the city of Addis Ababa was estimated to about 3.5 million inhabitants at the time of the study.
  4. Study and design of Water Supply Sources for the inhabitants and to their livestock population.
  5. Study and design various technologies for catchment rehabilitation which included the study and design of 17 dams, soil conservation measures, silt traps, buffer zones, etc. Especially for the 17 dam locations, the following studies were conducted:
    1. Water Resources Management Study along with Hydrological Assessment Study for three river basins.
    1. Feasibility Study Analysis for the construction of dams for water supply of Addis Ababa, irrigation demand in the vicinity of the reservoirs, preventing flood events, covering the needs of water of the livestocks etc.
    1. Hydro geological Study of the existing and new proposed boreholes locations within the program of developing a 40-deep well program construction in the area of Legedadi.
    1. Hydrological, geological and geotechnical investigations and analysis (preliminary and detailed).
    1. Dam design, dam safety analysis, monitoring plan, tender documents, bill of quantities, cost estimates (preliminary and detailed).
    1. Environmental and Social Impact Assessment (ESIA) Study and Resettlement Action Plan.
    1. Detailed Socio-Economic Study, including investment plan, financing options, funding proposals, etc.
    1. Construction Supervision of the projects finally incorporated to detailed design study.
  6. Training the appropriate staff of AAWSA in such a way that they could train other stake holders and also include preparation of training manual for continuous follow up and awareness creation. Lastly, the potential for hydropower production was examined.

The following dams were designed in a feasibility and detailed design phase:

  1. Menjaro dam: Composite dam with central concrete spillway and rockfill clay core embankments, H = 26.0 m. Capacity: 9.3MM3
  2. Doyo dam: Composite dam with central concrete spillway and rockfill clay core embankments, H = 13.0 m, Capacity: 6.7 MM3
  3. Legeberi dam: Composite dam with central concrete spillway and rockfill clay core embankments H = 13.0 m, Capacity: 1.8MM3
  4. On the Sendafa catchment: silt trap, H = 5.0 m.