Reducing Dam Impacts in the Kafue Flats
The Kafue Flats in Zambia is an amazing wetland landscape of grasslands, lagoons and reed beds, covering about 6500 km2 of the Kafue River Basin, a tributary of the Zambezi. They are home to more than 470 species of birds and a wide variety of mammals, including the endemic Kafue lechwe, a rare species of antelope. There are two national parks which together have been designated as a Ramsar site – a wetland of international importance. Apart from being a haven for wildlife, the Flats are also important for people’s livelihoods. It is estimated that about 700,000 people live in, or in the vicinity of, the Flats and many depend on floodplain agriculture, dry season cattle grazing and traditional fisheries for their livelihoods.
The ecosystem has been heavily influenced by natural cycles of floods and droughts, but this changed radically after the construction of two dams in 1969 and 1976. First,downstream from the wetlands, a hydropower plant was built in the Kafue Gorge. This dam now supplies approximately 40% of Zambia’s electricity needs. Because of the geography of the Kafue Flats a second dam was needed to ensure a steady supply of water and the Itezhi-tezhi storage dam was built 250 km upstream, with the Kafue Flats left wedged between the two dams.
As a result of the construction of the two dams, the river's natural flood patterns were replaced by a stable river level throughout the year. This change in water regime contributed to the decline of many species in the Kafue Flats area. The number of Kafue lechwe decreased to a third of its original 1970 population of 100,000, although poaching also played a role in this decline. In addition, lower fishery yields and reduced availability of grazing land as a result of the altered flooding regime have had detrimental effects on livelihoods.
The good news is that a partnership has been formed between key players, with the aim of addressing these problems. WWF has been working with the Zambian Ministry of Energy and Water and the Zambian Electricity Supply Company (ZESCO) to adjust the operational regime of the upstream dam, so that a more natural pattern of water releases is achieved. The work has included sophisticated (and expensive) modelling work, as well as the re-establishment of hydrological monitoring stations which had fallen into disrepair.
Initially, the partnership focused primarily on technical and institutional aspects. Subsequently, the importance of working with local communities was recognised by the partners. Addressing their specific needs in relation to the dam operations became a major focus of the Dialogue on Food, Water and the Environment, a separate project led by WWF aimed at improving food security in the basin. Numerous workshops where held with local communities in which the crucial importance of more water for cattle grazing emerged.
New operational rules for the Itezhi-Tezhi Dam, aimed at better balancing hydropower, ecosystem and livelihood needs, were launched in May 2004. Unfortunately, they are yet to be fully operationalized, as some problems with the model used to trigger releases emerged. Nevertheless, during the 2006 wet season, additional water releases were made by ZESCO. The follow-up work now focuses on tweaking of the model and extensive monitoring of wildlife and fisheries in the Flats, to ensure that the changes really are beneficial.
ZESCO is planning to build two further hydropower plants on the Kafue River. At Itezhi-Tezhi Dam, where currently tons of water run over the spillway every day, an 80 MW power plant is planned to exploit the energy of the released water. The original design of the dam provided for a power plant but finances were lacking at the time. This is one case where a new hydropower plant is likely to have a negligible additional environmental impact, as it would operate at an existing dam. So far, finance for the scheme has remained elusive. Furthermore, a second power plant is planned in the Kafue Gorge, just downstream from the existing plant. According to ZESCO, these two new plants are fully compatible with the new operational regime, as they would work with existing water releases. WWF will continue to work with ZESCO to ensure that this is the case and that the agreed changes will be fully operationalized and yield benefits for people and wildlife.
The Kafue experience shows that it can be worthwhile to look at mitigation options at existing dams (as recommended by the World Commission on Dams). Environmental flows in particular can be introduced retrospectively and can be extremely important for reducing environmental and social impacts. However, getting dam operators and governments to agree to releasing environmental flows is not necessarily easy, as any additional water release tends to incur a power generation penalty. Too often such water releases are seen as a waste, yet their impacts on people’s livelihoods can be dramatic. Examples like Kafue show that it is possible to find a more balanced approach, provided dam operators and decision-makers have the will and the sense of responsibility toward other users of the river basin. What has been achieved in Kafue can and needs to be replicated in more places, in Africa and elsewhere.
The author was at the time of writing with the WWF Global Freshwater Programme.
