Dams Draining Africa's Lake Victoria
Report Reveals How Uganda Dams are Draining World's Second Largest Lake
A report by an independent Kenya–based hydrologic engineer confirms that over–releases from two dams on the Nile in Uganda are a primary cause of the severe drops in Lake Victoria in recent years. The report, Connections Between Recent Water Level Drops in Lake Victoria, Dam Operations and Drought, finds that about 55% of the lake’s drop during 2004–05 is due to the Owen Falls dams (now known as Nalubaale and Kiira dams) releasing excessive amounts of water from the lake. The natural rock formation controlling Lake Victoria’s outflow was replaced by the first Owen Falls dam in the 1950s. The second dam was built with World Bank funding in the 1990s.
The lake, which has dropped 1.2 meters since 2003, was, at the end of 2005, at its lowest level since 1951. The receding shoreline has caused serious harm to water supply systems, boat operators and farmers. It is estimated that the lake catchment supports about one-third of the total population of Kenya, Uganda and Tanzania.(1)
The new study, which analyzed recent reports produced for the Government of Uganda and other publicly available information, comes to the following conclusions:
- The Owen Falls dams have been releasing more water than allowed by the operating rule agreed by Uganda and Egypt. This "Agreed Curve" is intended to ensure that the releases through the dams correspond to the natural flow of the river before damming. The dam operators’ permits dictate allowable flows based on this agreement.
- Based on the current Lake Victoria hydrology, as well as observations from the past 100+ years, the Owen Falls dams are likely over–sized.
- The lack of public information on dam releases, dam operations and river flows makes it difficult for independent experts to soundly judge the performance of existing and proposed hydroelectric projects on the Victoria Nile.
- With experts concluding that the future climate will likely involve drier conditions, lower lake levels, and lower downstream river flows, the lack of adequate stream flows will be exacerbated, making it increasingly more difficult for Victoria Nile dams to produce their projected power. This calls into question Uganda’s reliance on hydropower on the Victoria Nile as its primary source of electricity.
Possible climate change must be a major consideration in the development of more dams on the Nile. As the report states, "It is unknown if Lake Victoria will recharge to the high levels and outflow experienced during 1961–2000, and if such a recharge could occur, whether it would be in the next years or only in 100 years. Viable non–hydro, or at least hydro not on the Victoria Nile, power generating alternatives must therefore be considered for Uganda." Until the recent addition of emergency fossil–fuel plants, Uganda has been almost entirely dependent upon hydropower for its electricity needs.
The World Bank insisted in the 1980s that a second dam at Owen Falls, called the Owen Falls Extension Project, was Uganda’s "least–cost option," and provided funding for the second dam and repair of the original dam.(2) The extension project was engineered by the Canadian firm Acres International, which based its design on hydrological analysis that was considered too optimistic by many other experts at the time. The project did not undergo an environmental impact assessment; indeed, World Bank documents stated: "Extension of the existing plant at Owen Falls will have minimal environmental impact because the project will not affect downstream hydrology or fisheries."(3)
Frank Muramuzi, of the Ugandan NGO National Association of Professional Environmentalists (NAPE), said:
"This dam complex is now pulling the plug on Lake Victoria, with implications for millions. The blame is on three parties: The government for refusing to listen to any views about problems with these dams; Acres International, for suspect technical advice, and the World Bank for backing the project in the first place."
Lori Pottinger, of International Rivers, said:
"The amazing incompetence of the World Bank and Acres reveals the kind of hubris that fuels so many large dam projects. Africa cannot afford the Bank’s brand of high–risk projects any longer."
1. Living Lakes project, www.livinglakes.org
2. According to the World Bank Inspection Panel: "IDA has been involved in the power sector in Uganda for over 20 years and has financed several projects, beginning with emergency repairs to the Owen Falls Dam in the early 1980s. IDA financed the Power II Project in 1985 (around US$28.8 million) under which rehabilitation works were carried out for the Owen Falls Dam. In 1991, it financed the Power III Project with an original amount of US$125 million) for the construction of the Owen Falls Extension. In January 2000, it provided a Supplemental Credit to the Power III Project in the amount of about US$33 million. More recently, the Power IV Project was approved in July 2001 with a Credit of about US$62 million, which will assist in financing Power Generation Unit 14, and contingent upon economic viability, Unit 15 (40–80MW) at the Owen Falls Extension powerhouse." www.worldbank.org (PDF).
3. The World Bank Staff Appraisal Report, Uganda, Third Power Project, May 29, 1991.