Chad Basin demand for ivory, but stocks have since recovered. The seasonal Korama River in the south of Niger does not reach Lake Chad. Nigeria includes two sub-basins that drain into Lake Chad. The Hadejia - Jama'are - Yobe sub-basin in the north contains the Hadejia and Jama'are rivers, which supply the Hadejia-Nguru wetlands. They converge to form the Yobe, which defines the border between Niger and Nigeria for , flowing into Lake Chad. About of water reaches Lake Chad annually. Construction of upstream dams and growth in irrigation have reduced water flow, and the floodplains are drying up. The Yedseram -
Rail transport in Chad government to build a line that would open the colony’s interior to trade. The syndicate sponsored expeditions in 1902–3 and 1904 to survey the projected route. Several plans or proposals to build railways during the French colonial period (French Equatorial Africa) in Chad, and to connect Chad to other African railway networks (Cameroon, Nigeria, Oubangui/Central African Republic). Early proposals include a line extending from the Cameroon rail system at Douala into Chad in the 1930s. One early unofficial plan was a study for a railway from Douala in Cameroon to Bangui, which was part of the pre-World War I German