Water, Sewage & Effluent November-December 2017 | Page 39

Grim future In recent years the Mali government has been diverting water from the River Niger at the Markala barrage just upstream of the delta, to irrigate desert fields of thirsty crops such as rice and cotton. These diversions have cut the area of delta flooded About the author health to social breakdown and international migration are complex. Wetland loss is certainly not the only reason for the human exodus from the Sahel. And migration is a long-standing coping strategy for people living in a region of extreme climate variability. But the parlous state of the wetlands of the Sahel is changing the region. In the past, wetlands were refuges in times of drought or conflict. They were safe, and the water persisted even in the worst droughts. But today, with their waters diminished, these wetlands have become sources of outmigration. Now, migrations that were once temporary and local are becoming permanent and intercontinental. u annually by up to 7%, says Zwarts, causing declines in forests, fisheries, and grazing grasses. Some people have left the delta as a result, though it is unclear whether they have been among the Malians regularly reported to be in migrant boats heading from Libya to Italy. But this trickle of people from the delta could soon become a flood. In July this year, Mali’s upstream neighbour, Guinea, announced the go-ahead for Chinese firms to build a giant new hydroelectric dam, the Fomi Dam, in the river’s headwaters. Construction could begin as soon as December. The Fomi Dam’s operation will replace the annual flood pulse that sustains the wetland’s fecundity with a more regular flow that the Mali government intends to tap for a long- planned tripling of its irrigation along the river. Wetlands International estimates that the combined impact of the dam and irrigation schemes could cut fish catches and pastures in the delta by 30%. “Less water flowing into the delta means a lower flood level and a smaller flood extent,” says Karounga Keïta of Wetlands International in Mali. “This will have a direct impact on food production, including fish, livestock, and floating rice.” He fears that the inevitable outcome will be further human migrations from the wetland. The links in the chain from water management through wetland Fred Pearce is a freelance author and journalist based in the UK. He is a contributing writer for Yale Environment 360 and is the author of numerous books, including The land grabbers, Earth then and now: Potent visual evidence of our changing world, and The climate files: The battle for the truth about global warming. still mostly think of dams as infrastructure development that furthers economic activity and wealth – and partly because many environmental groups concentrate on the ecological impacts of dried wetlands, while ignoring the human. In this climate of ignorance, more wetlands are under threat. The next victim is likely to be the Inner Niger Delta, a wetland in northern Mali that covers an area the size of Belgium. The delta forms where West Africa’s largest river, the Niger, spreads out across flat desert near the ancient city of Timbuktu. The delta is a magnet for migrating European water birds. It is also currently one of the most productive areas in one of the w o r l d ’s p o o r e s t c o u n t r i e s . I t provides 80% of Mali’s fish, and pasture for 60% of the country’s cattle, and it delivers 8% of Mali’s GDP and sustains 2 million people, 14% of the population, says Dutch hydrologist Leo Zwarts. Its fish are exported across West Africa from Mopti, a market town on the shores of the delta. contributor As many as a million Nigerians have lost livelihoods because of dams that once fed a wetland that flowed into Lake Chad. The Markala Barrage in Mali, which diverts water from the River Niger for irrigating crops such as rice and cotton. Water Sewage & Effluent November/December 2017 37