Chad Basin depth of . Due to heavy pumping, since the start of the 1980s the water levels in both aquifers has been lowered, and some wells no longer function. There is a third, much lower, aquifer in Bima Sandstones that lies at a depth of . Both the current and historical areas of the basin and the mega-basin contain concentrations of fossils. Fossil-fuels deposits in the area are estimated to exceed a trillion barrels in reserves. The Lake Chad Basin Commission was set up in 1964 by Cameroon, Chad, Niger and Nigeria, the four countries that contain parts of Lake Chad.
Colony of Niger Tibesti Cercle ceded to Chad Colony in French Equatorial Africa, and in 1932, the colony of French Upper Volta was divided amongst its neighbors, with the Cercles of Dori and Fada N'gourma ceded to Niger Colony. Niger Colony officials, unlike neighboring Chad, remained loyal to the French Vichy government after 1940, and thus closed its southern border (to Nigeria) and eastern border until 1944. On 31 December 1946 the Military Territories of N'Guigmi and Agadez were ceded to Niger Colony, leaving only Bilma Cercle as the last military-run section of modern Niger. This area in the far north east only