Lake Chad the Yobe River in Nigeria/Niger. Despite high levels of evaporation, the lake is fresh water. Over half of the lake's area is taken up by its many small islands (including the Bogomerom archipelago), reedbeds and mud banks, and a belt of swampland across the middle divides the northern and southern halves. The shorelines are largely composed of marshes. Because Lake Chad is very shallow—only at its deepest—its area is particularly sensitive to small changes in average depth, and consequently it also shows seasonal fluctuations in size. Lake Chad has no apparent outlet, but its waters percolate into the Soro and
Niger River Fund. The World Bank approved a US$500 million soft loan in July 2007 to finance projects in the basin over a 12-year period. Funding will be awarded in two phases. The initial $185 million credit will go to Nigeria, Guinea, Benin, Mali and Niger. The second, $315 million investment, is slated for Burkina Faso, Cameroon, Chad and Ivory Coast. Besides financing the rehabilitation of dams in Nigeria, the loan will also fund the "sustainable management of selected degraded ecosystems and rehabilitation of small water infrastructure" and capacity building. In September 2009, the Nigerian government commenced a 36 billion naira dredging