Water loss due to evaporation and falling rainfall levels could significantly impact agricultural production in in the Volta River basin
By Kieran Cooke
Plans to boost food and energy production in one of West Africa’s most rapidly populating regions are likely to be put in jeopardy by water shortages brought about by rising temperatures, falling rainfall and increased evaporation, says a new report.
The Volta River is one of Africa’s main waterways. More than 24 million people in Ghana, Burkina Faso, Benin, Ivory Coast, Mali and Togo depend on the river and its tributaries for water. The output of hydro-electric plants on the river is also a key element in providing power for irrigation systems and for driving the region’s industrial growth.
The study, The Water Resource Implications of Changing Climate in the Volta River Basin by the International Water Management Institute and partner organisations, says there are indications that temperatures will rise by up to 3.6°C in the Volta River Basin over the next century – leading to significant water loss due to evaporation – while rainfall in the region could drop by 20%.
As a result water flows in the Volta and its tributaries could fall by 45%, “depriving the basin of water that countries are counting on to drive turbines and feed farms” says the study.
It says the decrease in water flows means that by 2100 hydro-electric power supplies on the Volta will fall – even with the addition of a number of new hydro-electric projects.
The Volta Basin is home to the massive Akosombo Dam, which has created Lake Volta, the world’s largest man-made lake by surface area and the world’s fourth largest reservoir in terms of volume. Next year the Bui Dam, a collaboration between Ghanaian and Chinese consortia, is due to come on stream, producing 400 MW for Ghana’s power grid.
The study predicts that the Bui Dam project – a controversial scheme which involves the resettlement of large numbers of people and the flooding of national park lands – and other planned schemes in the Volta Basin could fall a long way short of their potential due to climate change.
The report says poor farmers will be among those hardest hit by climate change-related water shortages.
Small and beautiful
“An unreliable supply of water for irrigation will have serious consequences for a region where most people are farmers”, says Matthew McCartney, lead author of the study.
“Beyond that, there is an urgent need to shift more food production away from rain-fed systems that are subject to the vagaries of climate to irrigated agriculture. “
While the study says future projections of water resources in the Volta River are not certain, the data collected contains some clear warning signs. Decision makers need to plan for a more resilient mix of options in terms of energy and agricultural production in order to adapt to climate change.
Wind and solar projects should be considered: water storage options should not be confined to projects that employ large dams, says the study, but should also involve relatively simple, small scale approaches to water storage, such as building small ponds on rural farms and using water tanks with roofs in order to reduce evaporation.
“Africa has the potential for innovation and solutions”, says study lead author McCartney. “We need to harness that innovation and combine it with solutions that we know work to feed Africa.”
This article was produced by the Climate News Network