French authorities on Wednesday set about draining a vast underground lake beneath the Alpine glacier of Mont Blanc to avert a potentially disastrous flood.
Some 65,000 cubic metres water has gathered in a cavity, dangerously raising the pressure beneath the mountain, a favourite spot for holidaymakers, officials said.
They estimated that if the water burst out it could flood the nearby valley of Saint-Gervais in half an hour and “nearly 900 families could be affected”. He said teams were setting up a pump to tap some of the water trapped some 250 feet below the surface, “to let out an initial jet of water in the afternoon to avoid the pressure—cooker effect.
