Lake Chad gives the Aral Sea a run for the money in the category of big-but-now-dry bodies of water. According to the United Nations, the lake has lost as much as 95 percent of its volume from 1963 to 1998. The shallow lake (it's only 34 feet deep when full and currently averages just less than five feet in depth) has been hit hard by changes in rainfall patterns, overgrazing, deforestation and increased demand by the surrounding populace. The lake almost dried up in 1908 and again in 1984. Aside from the environmental disruptions, the drying lake is also brewing up trouble between regional governments fighting over rights to the dwindling waters.