[1][2] This river is the longest and the largest di the West Timor area, with a length of 132 km.

The upstream rises from Mount Mutis, flowing in the southeast direction until discharging to Timor Sea near Besikama.

The watershed (Indonesian: Daerah Aliran Sungai/DAS) of Benanain has an area of 3,158 km2 comprising most of Malaka, Timor Tengah Utara and Timor Tengah Selatan Regencies, and also a small part of Belu Regency.

The Benanain River has a characteristic of very extreme discharge fluctuation, giving the indication that the condition of this watershed is in a serious damage.

[5] The inhabitants along the Benanain River use the water for agriculture and fisheries by traditional fishing or using nets.