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.
Tributaries
Some of the largest tributaries of the river are:
Baen River
Biau River
Asban River
Okan River
Muti River
Bunu River
Fatu River
Laku River
Besi River
Geography
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]
Uses
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.