Africa’s fourth-largest lake could drop by 20m, causing an ecological and human disaster to rival the shrinking of the Aral Sea in central Asia, if Ethiopia goes ahead with massive irrigation projects linked to a giant dam, according to a university paper.
Lake Turkana, located almost entirely in Kenya, but fed by the Omo River, which rises in Ethiopia, will be severely impacted by the 243m-high Gibe III dam, which is due to be completed this year, the study published by the University of Oxford’s African Studies Centre says.
It suggests water levels could drop by half, devastating the lake’s fisheries and affecting the livelihoods of 170,000 agro-pastoralists.
“Ultimately, the 6,400 square kilometer lake could reduce to two small lakes. The picture that emerges from these predictions bears a striking resemblance to the recent disastrous history of the Aral Sea, which was once the world’s fourth-largest inland water body,” said Sean Avery, a Nairobi-based hydrologist who studied the impact of the dam project for the African Development Bank.
The Aral Sea, which is shared between Uzbekistan and Kazakhstan, lost nearly 75 percent of its water in 30 years when vast amounts were abstracted by Soviet farmers from its feeder rivers to grow cotton. The result has been the collapse of the fishing industry, ill-health, climate change across the region and severe dust storms.
“The parallels [of the Aral Sea] with what might happen to the people and environment of Lake Turkana and a large part of northern Kenya are clear. On top of this, no feasibility studies or social and environmental impact assessments in the Lower Omo have yet been published,” Avery said.
The Ethiopian government says that the US$2 billion dam, which is intended to generate electricity for Kenya, Ethiopia, Djibouti and Somalia, will stop annual flooding of the Omo valley.
Avery said that major problems will occur when 450,000 hectares of irrigated sugar farming starts downstream of the dam.
“This will require a huge water abstraction from the Omo,” he said.
According to Avery, the water needed to fill the reservoir of the Gibe III dam will equal one year’s inflow into Lake Turkana.
“The lake level will fall up to two meters during reservoir filling, which is expected to take up to three years. The fall will be temporary, however, since the lake level will be substantially restored after another 16 years or so,” he said.
“The picture changes dramatically, however, when the potential effects of large-scale irrigation for industrial-scale sugar and biofuel plantations are considered. The land area allocated for commercial agricultural development is over 455,500 hectares, but the ultimate water requirement is unknown at present. One scheme for which water needs are known and which is now being implemented by the Ethiopian Sugar Corporation will equal in extent the entire irrigated area of Kenya — approximately 170,000 hectares,” he said.
The effect on the lake’s fisheries could be devastating, Avery said.
The Ethiopian government claims 150,000 jobs will be created by the plantations, but human rights groups, including Survival International and the Oakland Institute, say thousands of people are being evicted to make way for the irrigated plantations.
“The abuses being carried out by the Ethiopian government in the Lower Omo are incontrovertible,” said David Turton, an Oxford University anthropologist who has spent 40 years working in the Lower Omo valley. “Thousands of agro-pastoralists are being evicted by government [decree] from their most valuable agricultural land along the banks of the Omo to make way for government-owned irrigated sugar plantations.”