A newly discovered species of orangutan is among several animals under threat from a $1.6-billion-dollar hydroelectric dam project in Indonesia, conservationists have warned.

The joint Indonesian-Chinese dam development, scheduled for completion in 2022, will slice through the only known habitat of the critically endangered Tapanuli orangutan in the Batang Toru rainforest on Sumatra island.

The Tapanuli was recognised as one of three distinct species of orangutan as recently as 2017 and only about 800 remain in the wild. Dominant males of the species sport prominent moustaches while the females have beards.

Environmentalists have warned that the planned 510-megawatt dam, which aims to supply electricity to North Sumatra province, will impact up to 10% of the orangutan’s habitat through flooding and a network of roads and high-voltage power lines, and could lead to inbreeding.

Erik Meijaard, a biological anthropologist and specialist on the Tapanuli, told AFP the dam would be the “death knell” for the animal. “Roads bring in hunters (and) settlers – it’s the start, generally, of things falling apart,” he said.

The power plant is being constructed by Indonesian firm PT North Sumatra Hydro Energy, with backing from Sinosure, a Chinese state-owned enterprise that insures overseas investment projects, and the Bank of China.