The prefectures of Vakaga, Bamingui-Bangoran and Nana-Gribizi together contribute between 15.3 and 18.2% to the water supply of Lake Chad (source: Anon 2003, Odada et al., 2005).
All the permanent or temporary streams of the North region’s protected areas belong to the Chari watershed (hence to Lake Chad) with 3 main tributaries: Aouk, Bamingui and Gribingui. The North region’s rivers have extreme variations of flows between their flooding (in September-October) and low water phases (March-April).
The quantity of water available depends mainly on the rainfall, as well as on the nature of the soil and the topography influencing the water drainage.
The northern region is in the Soudano-Guinean climate zone and its average annual rainfall varies between 800 mm and 1,300 mm.