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.
Geography of Chad extends west into Nigeria and Niger. The larger, northern portion of the basin is bounded within Chad by the Tibesti Mountains in the northwest, the Ennedi Plateau in the northeast, the Ouaddaï Highlands in the east along the border with Sudan, the Guéra Massif in central Chad, and the Mandara Mountains along Chad's southwestern border with Cameroon. The smaller, southern part of the basin falls almost exclusively in Chad. It is delimited in the north by the Guéra Massif, in the south by highlands 250 kilometers south of the border with Central African Republic, and in the southwest by the