In the winter of 1911, a massive earthquake-induced landslide in the Pamir Mountains of eastern Tajikistan completely blocked the valley of the Bartang (Murgab) River, a headwater tributary to the Amu Darya River basin. A lake began to grow behind this natural dam and has now reached a length of 60 km. In a worst-case scenario that assumes collapse of the dam, a catastrophic outburst flood from Lake Sarez would destroy the villages and infrastructure in the Amu Darya basin between the lake and the Aral Sea, affecting an area inhabited by more than five million people across a distance of over 2000 km. But local populations in the mountain valleys face further, more immediate and pressing hazards; the annual cycle of rockfalls, debris flows, avalanches, and flooding constantly impinges on human activities. Development assistance is thus needed on a small, participatory scale in the form of enhancing existing local emergency response infrastructure. Moreover, monitoring Lake Sarez and designing an early warning system seem more appropriate measures than extremely costly engineering solutions to stabilise the dam, especially since collapse of the dam was assumed to be extremely unlikely.
