The Imja glacial lake is around three quarters of the way up Mount Everest. The lake levels were dangerously high, and there was concerns of flooding downstream settlements, trekking trails and bridges.
Nepal’s army was called in to drain the glacial lake to a safe level.
The lake, which was originally 149m deep in places, has had its water levels lowered by 3.4m.
Many of the lakes are said to be filling up fast because of accelerated melting of glaciers amid rising global temperatures.
Last year’s earthquake in Nepal is also feared to have further destabilised Lake Imja.