Stiegler’s Gorge: Read Prof Mwalyosi


IN 2009, Professor Raphael Mwalyosi of the University of Dar es Salaam conducted a research on environmental impacts of the proposed Stiegler’s Gorge hydropower project and he came up with some interesting findings.

Had the world’s critics read the findings, they would not be uttering irrelevant statements about environment degradation, if hydro electric power is generated in that particular area.

According to him, the establishment of the planned reservoir at Stiegler’s Gorge on the Rufiji River would enable a large amount of highly valued energy to be produced and this automatically guarantees President John Magufuli’s plan to implement the project soon.

In the report, Professor Mwalyosi said the power plant would represent an important national asset, though such a large net amount of energy would be realized on a short- to medium term basis.

The power production can be negatively influenced by a variety of reservoir operation options that would be related mainly to irrigated agriculture, fisheries, and water quality, which form trade-offs with hydropower generation, says the ecology don.

“The most significant effect of the dam would be drastic reduction, by controlled discharge, in the frequency of severe floods in the lower Rufiji valley. Floods in excess of 2,500 cubic metres of discharge per second could be reduced in number from some 14 to 3 in 24 years, or from 167 to 13 during 300 years” he said in the report.

This University of Dar es Salaam Professor said most devastating floods would also be reduced—from once in about 8 years to once in maybe 40 years, and this should well be understood by environmentalists who oppose the project without a prior knowledge about the project.

According to him, the Stiegler Gorge Project impact area contains a major wildlife resource in terms of size, density, and diversity, and its accessibility to Dar es Salaam gives it a great potential for tourism development, and critiques of the project should look the report and read it in detail to enable them have objective view about the project.

“As an access road to the dam-site would be a necessary prerequisite to implementation of the project, and it would indirectly help to open up the Selous Game Reserve to tourism, which is currently being hampered by poor communications,” says the Report.

Also, a substantial amount of the forest resources identified along this road could be exploited, says Professor Mwalyosi. According to this ecology professor, no complete populations of animal wildlife would be in danger from direct ecological consequences of river impoundment and dam construction.

However, he says, significant proportions of the populations in the project impact area of three species (Giraffe, Wildebeest, and Zebra) would be potentially at risk, owing to their need for habitats of restricted range.

He says that on the other hand, some species, including Crocodile and Hippopotamus, would increase in numbers following creation of the reservoir and improvement of their habitat downstream of the dam (due to swamp drainage).

“Not withstanding that the ecological impacts of dam construction are relatively minor, the socio-economic impacts on wildlife and conservation values are potentially great -resulting, for instance, from facilitated access to the heart of the Selous Game Reserve and concomitantly increased conflict between wild animals and Man” says Professor Mwalyosi’s report.

The report further says that river impoundment would have very negative impacts on floodplain fisheries and agriculture, the latter of which would probably be changed to irrigated agriculture with artificial fertilization, while floodplain fisheries would totally collapse.

“Some mangrove stands in the Delta would probably be displaced by reeds. Delta fisheries would be very negatively affected, because of changes in the water regime as well as in salinity levels” says the report.

According to professor Mwalyosi, Water quality in the planned reservoir and in the downstream area would be negatively affected by the project. The project would also have negative effects on the health of the riparian population, owing to increased potentials for disease vectors.

President Magufuli has decided to implement the project, though in the year 2011 a Brazilian business and public contractor giant Odebrecht Company Limited, with top global businesses and operations across a wide variety of industries, had showed interest in undertaking the huge Stiegler’s Gorge power project in Tanzania.

Till today the project never came to implementation, though the then Director General of the Rufiji Basin Development Authority (Rubada) Aloyce Masanja assured journalists that a team of experts from the Brazilian company had visited Tanzania to assess the project, and had concluded that it “was viable and easy to implement”.

The project was found to have potential to produce 2,100MW of power with three underground turbines. The expert’s report (Which later turnerd to be a while elephant) was presented to the Rubada board of directors who accepted it and the next step was signing of a Memorandum of Understanding (MoU) between the Brazilian company and Rubada.

As a sign of Tanzania’s commitment to the project, the then Prime Minister Mr. Mizengo Pinda even led a team of experts from Rubada, as well as other government officials to Brazil to learn about Odebrecht’s experience in producing hydroelectricity, but unfortunately, he left office without realizing the project.

Rubada optimistically believed that by 2015, the Stiegler’s Gorge power project would start producing electricity to bring substantial relief to the power crises that Tanzania was experiencing, but nothing came out as earlier speculated, and surprisingly, no reasons were given in association to that failure.

By 2011, Tanzania needed 1.500 MW of power and it had the capacity to provide 400 MW with just 14 per cent of its 40 million population connected to the grid, with demand increasing 15% annually.

Companies charging high capacity charges were seen as best option, instead of that planned hydro electric power. We should remember that the government officials held talks with their Brazilian counterparts in Sao Paolo in September 2010, on the construction of the proposed 2,100 megawatt (MW) Stiegler’s Gorge hydro-power station – By the way, what happened to those resolutions?

The power plant was to be constructed using Brazilian technology, and would generate excess power that could be exported to the east African and southern African power pools.

Masanja used to say that the plant would be a source of cheap, abundant energy at a cost of around 2 US cents of a dollar per kilowatt, but he never got support from relevant authorities, and one fails to know why..

According to him, the project would help control flooding in the Rufiji area and create a reservoir with a total capacity of 34 billion cubic metres to supply the commercial capital Dar es Salaam and other regions.

The fourth phase government considered to fund options for the project, including concessional loans, private investment or state financing and nothing was later reported about that development.

It was reported that Brazil would provide the technology to build the plant, and a government delegation from Brazil came to Dar es Salaam for further discussions on the project.

The project was planned to involve the installation of three giant underground turbines, each with the capacity of producing 700 megawatts of electricity. Most environmental impact assessments have so far showed the project would not affect the wildlife at the area.

We should therefore support Dr Magufuli on this grand project he intends to implement, which, if realized, can have a grand effect into the country’s economy, which has prioritised industries as its focal point.

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