Data from the United States Department of Agriculture shows a drop of about 1.5 metres in the lake’s water levels since January 2015, the rights group said.
It said that the shoreline in a gulf on the lake’s western edge has simultaneously receded as much as 1.7 kilometres over roughly the same period.
Falling water levels in Lake Turkana due to development of dams in Ethiopia are threatening food supplies in a part of Kenya where drought is already causing hunger, the non-governmental organisation Human Rights Watch warned on Tuesday.
That time frame generally corresponds with the filling of Ethiopia’s Gibe III dam. Water that previously flowed unimpeded into Lake Turkana is being held behind the dam.
The gulf is a key source of fish for Kenya’s Turkana people, it noted.
Further reductions in the lake’s water levels are forecast as Ethiopia proceeds with a massive agro-industrial project in the lower Omo Valley.
Indigenous pastoralists in Ethiopia are also being hurt by the dams and sugar plantations, the report said. “The predicted drop in the lake levels will seriously affect food supplies in the Omo Valley and Lake Turkana, which provide the livelihoods for half a million people in both Kenya and Ethiopia,” said Mr Felix Horne, an Africa researcher at rights watch
He said: “The Ethiopian government’s moves to develop its resources should not endanger the survival of indigenous people living downstream”.
Turkana County accounts for a substantial share of the 2.7 million Kenyans who are dependent on food aid due to poor rains received last year.
“Climate change is exacerbating the already significant problems the Turkana people face in getting sufficient food and water, and maintaining their health and security,” Human Rights Watch observed.
The Kenyan government “has done little to address the impact from Ethiopia’s Omo Valley development”, however, neither has it responded adequately to problems related to climate change, it said.
Kenya has specifically failed to pressure Ethiopia to take steps to reduce the damage caused by the dam and to consult local people.