Zim & Zambia forge ahead with Devil’s Gorge power project
Harare (New Ziana) – The Zambezi River Authority (ZRA) has invited bids for pre-feasibility studies for the proposed Devil’s Gorge Hydro-Electric Scheme (HES), to provide updated data on designs and cost estimates for the power project whose output will be shared equally between Zimbabwe and Zambia.
The Southern African neighbours are, through the ZRA, jointly pursuing the proposed Devil’s Gorge HES which is located at the tail end of Kariba Dam, downstream of the Gwayi/Zambezi Rivers Confluence.
The power project was conceived in 1972 out of a study instituted by the predecessor of the ZRA, the Central African Power Corporation, with a project analysis only conducted in 2016 by Tractebel Engineering S.A-France, but no Environmental and Social Impact Assessment has been conducted to date.
To move the project forward, the ZRA now wants a review of all available previous documentation on the Devil’s Gorge HES to firm up the scope of the proposed works.
The new study, the ZRA said, is expected to identify possible alternative optimal sites for the location of the Dam taking into account the findings of the technical, geotechnical, environmental, social and economic considerations.
“The objective of the assignment is to undertake prefeasibility studies that would investigate and recommend an optimal site, around the stretch between approximately 60km downstream of the proposed Batoka Gorge site and upstream of the area of influence of Lake Kariba,” the ZRA said.
“The initially recommended site shall also be analysed and compared with the other alternatives.”
Recommendations from the 1972 study included a 181m high concrete arch dam, 65m of which would be below water, two underground power stations on each side of the river with a total capacity of 1240 MW.
“From the long list of alternative sites, two shall be recommended analysed in detail and ranked based on a multi criteria to be agreed with the client,” it said.
“(The study is also expected to) propose an optimal installed capacity, informed by technical, environment, social and economic considerations. Propose an optimal configuration of the scheme considering the bilateral nature of the project.
“Prepare a detailed design report describing the scope of the proposed works, and clearly showing the design criteria adopted, assumptions made and the corresponding calculations. Confidential cost estimates of the works as well as an implementation schedule shall also be prepared and included in the report.”
The studies must be carried out over a period of approximately thirty weeks, the ZRA said.
Zimbabwe and Zambia are also jointly working on the 2 400-Megawatt Batoka Gorge hydro-electric power plant with the updating of the 1993 engineering feasibility studies and an environmental and social impact assessment already done.
On the other hand, Zimbabwe is working on several power projects which are at various stages of implementation as part of efforts to improve power supplies in the country.
For example, the expansion of the Hwange power plant through an addition of two generating units is on course, with the first unit expected to come online by mid-year.
The two units at Hwange will add another 600 megawatts to the national grid.