Batoka Gorge Dam Developments
by Peter Roberts,
In September 2012 plans for the proposed Batoka Gorge Dam and Mphanda Nkuwa Dam (Mozambique) were criticised by an American hydrologist for being based on historical hydrological data which has not been re-evaluated for future increased climate change risks.
"may be economically non-viable dams" which may "also be a danger because they were not designed to deal with the increasingly destructive floods ...The plans for two of the biggest dam projects on the Zambezi - the Batoka Gorge dam and Mphanda Nkuwa - are based on hydrological files and were not evaluated in relation to the risks associated with the reduction of average annual flow and more extreme cycles of floods and droughts."
The Batoka Gorge Dam was originally proposed in the early 1970s, and has been resurrected many times since. This time the previous stumbling blocks between Zambia and Zimbabwe have been resolved, and with funding from the World Bank the project look set to become a reality.
At the end of last year Zambezi River Authority (ZRA) invited Expressions of Interest (EoI) from prospective companies to develop the project proposals on a ‘Build Operate Transfer’ (BOT) basis, with EoIs to be submitted by 8 Feb 2013.
A project summary was included with the formal notice of invitation:
"The Batoka Gorge HES is to be located across the boundary between Zambia and Zimbabwe at 18º 1’ S 26º 34’ E, upstream of the existing 1,470 MW Kariba Dam hydroelectric scheme. The proposed scheme includes a 181 m high Roller Compacted Concrete (RCC) gravity arch dam, radial gated crest type spillway, two underground power stations on each side of the river with four 200 MW Francis turbines installed in each, giving a total capacity of 1,600 MW for the scheme. The scheme is designed as a run-of-the river scheme with an estimated average energy generation of 8,700 GWh/year. The reservoir is fully located within the Batoka Gorge and has a relatively small surface area of 26 km2."
The project is due for completion by 2019, and at least one company, from Brazil, is known to have expressed formal interest in tendering for the project. The next stage will be revising the now outdated 1993 technical feasibility and environmental impact studies to determine actual works, financing costs and environmental impacts for the project.
The proposed dam site is situated on the Zambezi River approximately 3km downstream of Mwemba Falls and 54km downstream from the Victoria Falls. The Grid Reference for the proposed Batoka Gorge Dam is ML 055-178 on the 1:50,000 scale topographical maps from both Zambia and Zimbabwe (GPS 18º 1’ S 26º 34’ E).
The proposed maximum fill level for the reservoir which will flood the gorge has been determined as 762 m above sea level, with the resulting lake flooding the Zambezi rapids upstream to just below the outlet for the Victoria Falls YES, and only short distance downstream from the Victoria Falls themselves.
See also our previous report on this project
To read more details about this proposal click here