Lake Chad is a historically large, shallow, endorheic lake in Africa, the size of which has varied over the centuries. Lake Chad is economically important, providing water to more than 30 million people living in the four countries surrounding it (Chad, Cameroon, Niger, and Nigeria) on the edge of the Sahara Desert . It is the largest lake in the Chad Basin. Lake Chad is located mainly in the far west of Chad, bordering on northeastern Nigeria.
The lake is home to more than 44 species of algae, and has large areas of swamp and reedbeds. The floodplains on the southern lakeshore are covered in wetland grasses such as Echinochloa pyramidalis, Vetiveria nigritana, Oryza longistaminata, and Hyparrhenia rufa.
There are many floating islands in the lake. It is home to a wide variety of wildlife, including hippopotamus, crocodile (both in decline), and large communities of migrating birds including wintering ducks, ruff (Philomachus pugnax) and other waterfowl and shore birds.