A complex of earth movement, which began in the Miocene and eventually resulted in the faulting of the Western Rift Valley, caused the reversal of the previous east-west drainage (1). River Kafu once flowing westwards began to flow eastwards. Lake Kyoga was then formed by ponding-back of the Kafu river. The lake lies in the flooded branches of the low west-flowing Kafu river. It receives the outflow from the Victoria Nile and is drained northward and then westward over the low northern end of the Rift escarpment (the Murchison Falls) to Lake Albert. The lake occupies a very shallow saucer-like depression. Depth does not exceed 5.7 m and greater part is less than 4 m. Large areas less than 3 m are covered by a continuous growth of water lilies. Shoreline is everywhere fringed with papyrus and other swamps sometimes forming a belt of several miles width between land and the open water.

The lake is divided into three environments: the open water deeper than 3 m; the water less than 3 m deep which is covered completely with a growth of water lilies; the swamps chiefly papyrus, which fringe the shoreline (2).

The fish fauna of the lake is more akin to Lake Victoria than to Lake Albert. The majority of 46 species recorded are found in Lake Victoria (2). The lake lacks any large predatory fish except a native species; hence abundance of Haplochromis and other small defenceless species. Nile perch was stocked in the late fifties. The fishery accounted for 60% of national production in 1983. It is Government strategy to start cropping Engraulicypris abundant in the lake. There are numerous floating papyrus islands in the lake. In stormy weather, they are blown about the lake. This is hazardous to set nets. Crocodiles were abundant in the lake (2).

Fishermen of surrounding communities practice long line fishing, inshore weed fishing or river fishing with primitive traditional gears. The lake provides papyrus which is widely used for making mats, roof thatch, fishing floats and rafts. Most of the operational factories around the drainage basin are now defunct; hence pollution (industrial) is not a problem (Q).