Lake Victoria in East Africa is by far the largest lake in the continent and the world’s largest tropical lake by surface area covering about 23,146 square miles. The lake is the world’s second largest freshwater lake. Lake Victoria ranks as the world's ninth largest lake by volume and has an average depth of 430 feet, and the deepest point reaches 2,006 feet below the surface. The total catchment area for Lake Victoria covers an area of 65,583 square miles and has a shoreline that stretches for 4,438 miles. The lake lies between the three East African countries of Uganda, Kenya, and Tanzania. Rainfall accounts for about 80% of the lake’s water, while 20% originates from the streams and rivers flowing into the lake. The major river that feeds the lake is the Kagera River, which exits the lake on the western shore. Other small rivers feeding the lake include rivers Migori, Mogusi, Sondu Miriu, Nyando, Yala, Nzoia, and Sio. The only outflow from Lake Victoria is the Nile River which flows from the northern shore of the lake near the town of Jinja in Uganda. John Hanning Speke, a British explorer, named the lake after Queen Victoria. Speke was on a journey together with his compatriot Richard Francis Burton, trying to identify the source of the river in 1858.
Primary Inflow of Lake Victoria
Kagera River is the major river flowing into Lake Victoria and forms part of the upper headwater of the Nile River. The part of the river known as Kagera has its origins in Burundi and flows out of Lake Rweru. The river flows eastwards from the lake following Burundi-Rwanda border and Tanzania-Rwanda border and later joins with Ruvubu River. Kagera River is joined by two principal tributaries of Nyabarongo in Rwanda which flows to Lake Rweru and Ruvubu in Burundi. It is not clear which is the longest out of the two feeders. At the confluence, the river flows towards the north along the Tanzanian-Rwanda border over the famous Rusumo falls and stretches through Akagera National Park and finally meanders to form Uganda-Tanzania border and finally discharges its water into Lake Victoria in Uganda.
Primary Outflow of Lake Victoria
The mighty Nile River is the only river draining water out of Lake Victoria, and it exits the lake near the town of Jinja in Uganda at Ripon Falls, and it flows northwards for some 81 miles to Lake Kyoga. The river stretches for another 120 miles beginning from the western side of the lake and flows westward to the south of Musindi Port. The Nile river then flows northward through Sudan to Egypt to discharge its waters to the Mediterranean Sea after covering a total distance of 4,130 miles journey. The Nile River is East Africa’s longest river and has a drainage basin that covers an area of 1,256,591 square miles or approximately 10% of the total land area of the African continent. The discharge volumes vary significantly along the course of the river, and it depends on factors such as diversion, weather, evapotranspiration, evaporation, and groundwater flow.
Pollution in Lake Victoria
Pollution has been a major problem in Lake Victoria and particularly the raw sewage, which is discharged into the lake. Other forms of pollution include chemicals from farms in the surrounding regions, fertilizers, industrial waste, and domestic refuse, which find their way into the lake. Generally, the lake’s basin is primarily a rural area with several centers of populations. The shores of Lake Victoria is dotted with cities and towns which include Kisii, Kisumu, and Homabay on the Kenyan side of the lake the Ugandan side has towns such as Entebbe, Jinja, and Kampala, while on the Tanzanian shore are towns such as Musoma, Mwanza, and Bukoba. These urban centers have industries which discharge chemicals and wastes to the rivers and streams flowing into the lake.