The scope of this project is the development of a coherent framework of principles and practices, established in international practice, for achieving the overall goal set by the Client and defined as reducing AAWSA’s overall Non-Revenue Water (NRW) from a current level of about 36% to 40% to a level of 20% by the year 2020. Addis Ababa and its surrounding areas has currently population estimated at about 3.5 million inhabitants. The total pressurized water network length is 3,700 Km.
All aspects of NRW management were addressed in the project. In order to achieve the overall project goal a Strategic Plan was implemented including the following tasks:
- Review of Existing Situation.
- Organizational Structure Assessment.
- Bulk Flow Meter Installation and Replacement Proposals
- Sampling and Testing of Existing Customer Meters
- Development of Specifications for the Procurement of New Customer Meters and Test Benches.
- Development of strategic (skeletal) and all-mains hydraulic models.
- Development of a GIS Management System for the Addis Ababa water supply network
- Implementation of ten pilot District Metered Areas and active leakage control activities using acoustic techniques.
- Initial and End Case Water Audits and evaluation of Performance Indicators.
-Training and Institutional Capacity Building.
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 is mainly divided into 6 components. These include: 1) Review of the master plan of the catchments, 2) Identification of stakeholders and clearly show the positive and negative impacts of the project on the stakeholders,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, 4) Study and design of Water Supply Sources, 5) Study and design various technologies for catchment rehabilitation which includes the study and design of 17 dams, soil conservation measures, silt traps, buffer zones, etc., 6) Training the appropriate staff of AAWSA. Potential Hydropower production was examined.
More specifically, the following dams have been designed in a feasibility and detailed design phase:
i. On the Menjano Catchment: earth fill dam with clay core and apparent structures, H = 26.0 m.
ii. On the Doyo catchment: earth fill dam with clay core and apparent structures, H = 13.0 m.
iii. On the Legeberi catchment: earth fill dam with clay core and apparent structures, H = 13.0 m.
iv. On the Sendafa catchment: silt trap, H = 5.0 m.
CONSULTING SERVICES FOR FEASIBILITY STUDY, DETAILED DESIGN AND TENDER DOCUMENT PREPARATION FOR SIO-SANGO IRRIGATION DEVELOPMENT AND WATERSHED MANAGEMENT PROJECT (KENYA)
The objective of the assignment is to carry out feasibility studies, detailed designs and tender documentation for the following infrastructure:
1) Sio-Sango dam (with connected small hydropower facilities). The characteristics of the dam are:
Dam Type = Rock fill with clay core, Dam Height = 20.00 m, Reservoir Capacity = 5,700,000 m³, Dam Length = 800m, Dam Volume=150,000 m³ and 2) Sio-Sango irrigation project and water supply facilities. The proposed project aim at developing irrigated agriculture estimated at 1,790ha.
The project includes all the necessary specialised activities and studies required for the identification of the optimal scenario for the implementation of the planned infrastructure, such as Stakeholder Management Plan, Environmental Impact Assessment, Cost-Benefit Analysis, Financial Analysis, etc.
DAM AND IRRIGATION SITES FINAL DESIGN OF 4 SITES FOR LAND HUSBANDRY WATER HARVESTING AND HILLSIDES IRRIGATION (LWH) PROJECT (RWANDA)
The main project's component was the detail feasibility study of the dams and supplemental irrigation infrastructure necessary for hillside irrigation at four sites (Nyanza-23 Karongi-12, Karongi-13 and Gatsibo-8). For each dam and irrigation sites, the study included review of existing designs and studies, field visits and geotechnical investigations, detailed design of dams and irrigation networks, preparation of tender documents, design workshops with the Service and the Panel of Experts and dam safety calculations
The four (4) schemes had the following characteristics:
- The Nyanza 23 scheme the study concerned a total area of 450ha corresponding to an annual irrigation water demand of 1.3 million cubic meters and included the design of a clay core earth fill dam of 19m height with a total embankment volume of 77,500m3, the reservoir capacity was 1.82 MM3.
- The Karongi-12 scheme the study concerned a total area of 255ha corresponding to an annual irrigation water demand of 0.65 million cubic meters and included the design of a clay core homogenous dam of 22.5m height with a total embankment volume of 118,850m3, the reservoir capacity was 0.68 MM3.
- The Karongi-13, scheme the study concerned a total area of 304ha corresponding to an annual irrigation water demand of 1.07 million cubic meters and included the design of a clay core homogenous dam of 22.5m height with a total embankment volume of 208,000m3 the reservoir capacity was 1.17 MM3.
- The Gatsibo-8 scheme the study concerned a total area of 90ha irrigation and included the design of a clay core earthfill dam of 17.0m height with a total embankment volume of 172,410m3, the reservoir capacity was 0.6 MM3.
Z&A was involved with the detailed design of the irrigation networks in all sites with a total area of 1099 ha, the geological investigations and the full hydro geological assessment of the four dam site areas.
Water transmission and distribution networks designed for this project consisted of: (a) 32,000 m HDPE DN500 water pipes for Karongi-12 area, (b) 48,000 m HDPE DN630 water pipes for Karongi-13 area and (c) 21,000 m HDPE DN450 water pipes for Nyanza-23 area.
CONSTRUCTION SUPERVISION OF THE MWOMBOSHI DAM AND PREPARATION OF DAM SAFETY PLANS
The overall objective of the assignment is the supervision of the construction works for the Mwomboshi Dam and appurtenant structures in accordance with the International Federation of Consulting Engineers (FIDIC) Conditions of Contract.
The Mwomboshi site is developed on both banks of the Mwomboshi River, in Chisamba District in Central Province to the east of the Great North (T2) Road, and covers a total area of around 5,150 ha gross.
The main element of the design is the Mwomboshi dam (23m High). The Dam will collect water from a 954 km2 catchment, extending up to Mukamwanji Hills at the north, Lileta at the west and Namingele Hill at the south and is expected to irrigate an area of approximately 5,170 ha.
The team was mobilized on site on early January 2017, following the mobilization of the contractor. Construction works are underway.
Z&A was responsible for the detail design of the Dam.