Water, Sewage & Effluent November-December 2017 | Page 37

Farmers once planted their crops in the wet soils as the waters receded. Pastoralists grazed their animals where forests and wildlife flourished. But the dam and its related projects are estimated to have resulted in the loss of 90% of the fisheries and up to 47  750 hectares of fields that were previously covered by water from the rising river during the wet season, a system of natural irrigation known as flood-recession agriculture. The Senegal River Basin Development Organization – the intergovernmental agency that is responsible for the dam project and is known by its French acronym, OMVS – conceded in 2014 that eliminating the river’s annual flood “has made flood-recession crops and fishing on the floodplain more precarious, which makes the rural production systems of the middle valley less diversified, and therefore more vulnerable”. This is clearly at odds with the organisation’s mandate to “ensure food security for all people within the river basin and region”. But Amadou Lamine Ndiaye, the OMVS’s director of environment and sustainable development, told me his agency regarded wetlands such as river floodplains primarily as a source of revenue for tourists, rather than as a lifeline for rural communities. Worse still is the crisis affecting the region around Lake Chad, which until half a century ago was Africa’s fourth largest lake, straddling the border between Nigeria, Niger, Chad, and Cameroon. The lake has lost more than 90% of its surface area since then. Initially, this was largely due to persistent droughts in the Sahel that often dried up the rivers supplying it with water. Since 2002, rainfall has improved markedly, but Lake Chad has not recovered. That is because of dams on the rivers flowing into the lake from the wetter south, mainly in Cameroon and Nigeria. The Maga Dam in Cameroon has diverted 70% of the flow of the Logone river to rice farms. This has both dried up part of the floodplain pastures that once supported 130  000 people, and dramatically reduced inflow to Lake Chad. In northern Nigeria, up to one million people have lost livelihoods because of dams on the River Yobe that once fed the Hadejia-Nguru wetland and flowed on into Lake Chad. In both cases, says Edward Barbier, an environmental economist at Colorado State University, the dams have had an overall negative effect on local economies, as losses to fishermen, pastoralists, and others exceeded gains from irrigation agriculture.  Social breakdown The poverty is driving social breakdown and conflict all around the lake. Mana Boukary, an official of the Lake Chad Basin Commission, an intergovernmental body, told Duetsche Welle two years ago: “Youths in the Lake Chad Basin are joining Boko Haram because of lack of jobs and ‘Food security’ contributor fisheries and up to 47  750 hectares previously covered by water. L a s t y e a r, I t r a v e l l e d w i t h Wetlands International, a Dutch- based environmental NGO, along the valley of the River Senegal, which forms the border between Senegal and Mauritania. Farmers, herders, and fishermen told of their battles against the ecological breakdown that has followed the building of the Manantali Dam, which is located upstream in Mali and was completed in 1987. The dam holds back a large part of the river’s seasonal flood flow to generate hydroelectricity for cities and provide irrigation water for some farmers. But there have been more losers than winners. Seydou Ibrahima Ly, a teacher in the bankside village of Donaye Taredji in Podor district, said that when he was young, “the river had a flood that watered wetlands where fish grew”. But “now there is no flood because of the dam… Compared to the past, there aren’t many fish. Our grandparents did a lot of fishing, but we don’t”. With their livelihoods gone, more than 100 people had left his village, he said. “In some villages, they are almost all gone.” “The migrants know the boats [travelling to Europe] are dangerous, but they have a determination to go and find a better life,” said Oumar Cire Ly, deputy chief of neighbouring Donaye village, which has also seen an exodus of its young people. The major wetlands and water basins of the Sahel region in Africa. Water Sewage & Effluent November/December 2017 35