A large barrier lake has formed in Nepal’s mountainous region after the natural flow of a river was obstructed. The lake’s dam could break at any time, potentially releasing a sudden, large volume of water downstream and placing nearby settlements and infrastructure at renewed severe risk.

On Thursday morning, the lake held about 2 million cubic metres of water. A further 3 million cubic metres could enter the lake over the next three days, bringing its total volume to an estimated 5 million cubic metres.

The expected increase in water is reported to have greatly raised concerns that the lake’s natural dam may fail. If a breach occurs, water could move rapidly along the river corridor, threatening communities and infrastructure around the river.