A large barrier lake has formed in Nepal, with Chinese authorities warning that the lake is already overflowing and could breach as more water flows into it over the coming days.

China’s Ministry of Water Resources estimated the lake’s volume at about 2 million cubic metres as of yesterday morning. Another 3 million cubic metres of water is expected to enter the lake over the next three days, creating a high risk of a breach, China Central Television reported, according to the Global Times.

The lake has formed near the confluence of the Chhochen Khola and Purepu Tsangpo rivers in Nepal. Chinese authorities are closely monitoring its development and carrying out flood simulations to assess the possible consequences of a breach and support emergency rescue operations.

The Chotchen and Purupe rivers originate in Tibet and merge before crossing into Nepal, where the river is known as the Bhotekoshi. The Bhotekoshi is the principal upper tributary of the Trishuli river.