| Benanain River | |
| Name Other: | Mota Benenain, Mota Benain, Benoin River, Sungai Benain, Noil Benain, Benain River |
| Source1: | Mount Mutis |
| Mouth: | Timor Sea |
| Mouth Location: | Malaka |
| Subdivision Type1: | Country |
| Subdivision Name1: |  Indonesia |
| Pushpin Map: | Indonesia Lesser Sunda Islands |
| Pushpin Map Caption: | Location of river mouth |
The Benanain River is a river of western Timor, Indonesia.[1] [2] This river is the longest and the largest di the West Timor area, with a length of 132 km. The river is located in three regencies: Malaka, Timor Tengah Utara and Timor Tengah Selatan, province East Nusa Tenggara, Indonesia. 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. It is the largest watershed in the East Nusa Tenggara province. 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. Consequently, every year this river causes big flooding.
Some of the largest tributaries of the river are:
The river flows in the middle south of Timor with predominantly tropical savanna climate (designated as Aw in the Köppen-Geiger climate classification).[3] The annual average temperature in the area is 26 °C. The warmest month is November, when the average temperature is around 29 °C, and the coldest is June, at 23 °C.[4] The average annual rainfall is 1760 mm. The wettest month is January, with an average of 305 mm rainfall, and the driest is September, with 5 mm rainfall.[5]
The inhabitants along the Benanain River use the water for agriculture and fisheries by traditional fishing or using nets. The Benanain Dam[6] in Kakaniuk village, district of Malaka Tengah, Malaka Regency, can distribute water to 15,000 hectare of farmlands. Other than agriculture, the dam is also used for flood prevention.
This river is a habitat of local crocodiles.[7]