Lower Kihansi Hydropower Project: An Evaluation of the Project Against World Commission on Dams Guidelines

In July 1995, the Government of Tanzania began construction of the 180–megawatt Lower Kihansi Hydropower Project (LKHP) in order to meet the growing electricity demands of its mining and tourism industries. The World Bank jointly funded the $275 million project along with the European Investment Bank and development agencies from Norway (NORAD), Sweden (SIDA), and Germany (KfW). Formally commissioned in July 2000, the project has been supplying electricity to the Tanzania Electricity Supply Company (TANESCO), the parastatal that owns and operates the project, since December 1999.

With its 25–meter dam and relatively small 26–hectare reservoir, the LKHP appears on paper to be a relatively environmentally benign project. In spite of its small size, though, the project has had drastic impacts on biodiversity. The Kihansi Gorge ecosystem is one of only 25 Global Biodiversity Hotspot as designated by IUCN. It is home to numerous endemic flora and fauna species that lived in the spray of the gorge’s 800–meter–high waterfall. This waterfall was destroyed by the dam, which collects water above the gorge, diverts it into a series of tunnels running into and out of the power plant, and returns the water to the river at the bottom of the gorge, 6 km downstream. The loss of the spray from the waterfall, which was laden with mineral–rich silt, has sent the critically endangered Kihansi Spray Toad and at least two endangered plant species to the brink of extinction. The previously unknown Kihansi Spray Toad exists nowhere else on earth, and the dam has already destroyed over 90% of its habitat. Efforts to rescue the toad through a captive breeding program and the installation of a sprinkler system in the gorge have failed to stabilize population levels.

The pending extinctions are a direct result of the World Bank’s failure to require a thorough Environmental Impact Assessment before it financed the LKHP. It also failed to require that the project’s design and operation be changed after environmental impacts were better understood. This is a clear violation of the Bank’s own policies, and a flagrant breach of their commitments under the International Convention on Biological Diversity.

Alternatives exist that would sustain the Gorge Habitat and ensure that the LKHP remains economically viable. These alternative proposals would increase instream bypass flows to seven cubic meters per second in order to create sufficient spray from the waterfall. Nevertheless, the World Bank and other funders have opted not to oblige the Government of Tanzania to implement this option.

The following briefly evaluates the project against the guidelines of the World Commission on Dams.

Sustaining Rivers and Livelihoods

WCD Recommendation
The WCD calls for policies to "maintain selected rivers with high ecosystem functions and values in their natural state." It further recommends that consideration of options places priority on "avoiding or minimizing negative impacts on endangered species" and "respecting the provisions and guidance of relevant international treaties."

Reality on the Ground
Kihansi Gorge is home to an enormous variety of plants and animals. Some of them, like the Kihansi spray toad and a species of wild coffee, live only in the waterfall spray zone and are therefore left critically endangered by this project. The growing likelihood that the LKHP will lead to the extinction of these species puts the project in violation with commitments made by Tanzania and the donor countries under the International Convention on Biological Diversity.

Impact Assessment

WCD Recommendation
The WCD states that all projects "should include an Environmental Impact Assessment (EIA)" that "complies with international standards" and is "sufficiently detailed to provide a pre–project baseline against which post–project monitoring results can be compared."

Reality on the Ground
No EIA was carried out before the project began. The World Bank conducted an environmental assessment as part of the project feasibility study in the early 1990s. When NORAD joined the project in 1994, it found the World Bank’s environmental assessment so deficient that it financed an EIA in 1995. This EIA was also found to be of very poor quality because it contained inadequate data and failed to include adequate water–discharge and dam management plans. The Kihansi spray toad and two rare plants were discovered in 1996, one year after dam construction began. For unknown reasons, TANESCO was not informed of this development until 1998.

Project Preparation

WCD Recommendation
The WCD states that dam developers must provide "sufficient evidence to demonstrate that proposed mitigation and development measures will be effective in meeting their objectives."

Reality on the Ground
Measures put in place to avert the extinction of the Kihansi spray toad have failed thus far. Many of the toads involved in the captive breeding program have died, and the sprinkler system installed in the gorge to simulate waterfall spray is constrained by problems with silt clogging the tiny sprinkler openings.

Environmental Flow Assessments

WCD Recommendation
The WCD calls for the definition of "an environmental flow requirement to maintain downstream species, ecosystems and livelihoods" before the dam is constructed. It also states, " Releasing tailor–made environmental flows can help maintain downstream ecosystems and the communities that depend on them."

Reality on the Ground
No such environmental flow requirement was determined prior to construction. Since then project authorities have resisted efforts to increase downstream flows, because they claim additional releases will not allow them to produce enough power. The project feasibility study only analyzed impacts on habitat flooded by the reservoir. The report failed to mention any impacts on the Kihansi Gorge ecosystem.

Addressing Existing Dams

WCD Recommendation
The WCD states that problems from existing dams should be addressed: "Management and operation practices must adapt continuously to changing circumstances over the project’s life and must address outstanding social issues – The effectiveness of existing environmental mitigation measures is assessed and unanticipated impacts are identified; opportunities for mitigation, restoration and enhancement are recognised, identified and acted on."

Reality on the Ground
The owners of the dam have consistently worked to maximize power output and minimize mitigation efforts. In spite of extensive research concerning the project’s impact on endangered and threatened species existing within the Gorge, project authorities and donors refuse to implement necessary mitigation measures. In fact, TANESCO is operating the dam without rights to the Kihansi River’s water, so it does not even have permission to divert any water from the Gorge. The Government of Tanzania is not forcing TANESCO to comply with existing water rights because of demands for power.