Hydroelectric Power Generation at Jamba Ia Oma and Jamba Ia Mina
Plans to develop two further hydropower stations in the Upper Kunene, in addition to those at Matala and Gove, were originally developed in mid-1970 and are now being brought to fruition.
The two sites chosen are at Jamba Ia Oma and Jamba Ia Mina, between the Gove dam and Matala weir (see Map of Existing and Planned Infrastructure). Both schemes were originally conceived to supply power to the Lobito Mining Company (Companhia Mineira do Lobito) although due to changing conditions substantially different operating conditions are foreseen. In addition to electricity generation both dams would now also serve to provide domestic drinking water and supply irrigation as well as serving to further regulate the flow of the Kunene.
The Jamba Ia Oma site lies around 50 km downstream from the Gove dam. Studies propose a dam her with a maximum height of 46.2 m, creating a reservoir with a volume of 1.1 km³. The resulting 40 m drop between the reservoir surface and the turbines located directly at the foot of the structure would serve to provide an estimated 50 MW of electricity.
The Jamba Ia Mina site is a further 60 km downstream. The 23.5 m high dam would create a reservoir of 0.57 km³ and would convey water to the power house 7 km further downstream. A total height difference from the reservoir surface to the turbines of 90 m is foreseen, providing the station with a potential capacity of 126 MW.
The Baynes Hydropower Project
In the late 1980s, SWAWEK (now NamPower) forecasted an increasing demand for power in Namibia and began to consider the construction of a hydropower scheme in the vicinity of the Epupa Falls area. In 1991, the governments of Namibia and Angola agreed to go ahead with the detailed technical and environmental investigations, with the studies commencing in 1992. Between 1995 and 1998, NamAng conducted a full Feasibility Study and EIA for a range of hydropower schemes.
The foot of the Epupa Falls.
Source: Broecke 2010
( click to enlarge )
During the study all possible hydropower development sites along the Kunene downstream of Ruacana were investigated, with the sites at the Baynes area and Epupa Falls eventually selected as the most technically viable. Further work continued on these two sites, with comparisons made in terms of technical, social, and ecological aspects. The Feasibility Study concluded that the Epupa Site would be technically preferable (i.e. greater storage capacity), while the Baynes Site would result in far less ecological and social impacts as a result of a smaller inundated area, resulting in less destruction of habitat and natural resources, less water loss through evaporation, and significantly reduced human impact, such as loss of access to grazing, physical resettlement, and loss of grave sites. The Epupa Project would have been far more disruptive to the life of the local Himba people since it would require the flooding of a broad valley extensively used by farmers and herders (ERM 2009).
Opposition to the plans of a dam at the Epupa Site by local and international NGOs and the Himba, saw the project being shelved and caused the two governments to consider alternative power supply arrangements, and pursue the development of a hydropower scheme at the Baynes site.
The proposed Baynes Hydropower Project will comprise a hydropower plant on the Kunene River 40 km downstream of the Epupa Falls with an installed capacity of about 465 MW and an average energy production of 171 MW.
The dam will be constructed to achieve a reservoir water level at a maximum of 580 m, ensuring the foot of the Epupa Falls, which is at an elevation of 580 metres, is not flooded, even when the reservoir is at full supply capacity. The reservoir at its full supply capacity would have a surface area of 57.67 km², a volume of around 2 000 Mm³, second in size only the reservoir behind the Gove Dam.
The final scoping report for the Environmental, Social and Health Impact Assessment (ESHIA) for the Baynes Hydropwer project can be downloaded here.
