The Malagarasi River is Tanzania

Tanzania

The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...

's second longest river. It empties into the eastern side of Lake Tanganyika

Lake Tanganyika

Lake Tanganyika is an African Great Lake. It is estimated to be the second largest freshwater lake in the world by volume, and the second deepest, after Lake Baikal in Siberia; it is also the world's longest freshwater lake...

 about 25 miles south of Kigoma

Kigoma

Kigoma is a town and lake port in western Tanzania, on the eastern shore of Lake Tanganyika and close to the border with Burundi. It serves as the capital for the surrounding Kigoma Region and has a population of 135,234 and an elevation of 775 m.The historic trading town of Ujiji is 6 km...

, and is one of the lake's primary inflows. The Malagarasi pre-dates Lake Tanganyika and was formerly a tributary of the Congo River

Congo River

The Congo River is a river in Africa, and is the deepest river in the world, with measured depths in excess of . It is the second largest river in the world by volume of water discharged, though it has only one-fifth the volume of the world's largest river, the Amazon...

 to its west. The first 80 kilometres of the river forms the international boundary between Tanzania and Burundi

Burundi

Burundi , officially the Republic of Burundi , is a landlocked country in the Great Lakes region of Eastern Africa bordered by Rwanda to the north, Tanzania to the east and south, and the Democratic Republic of the Congo to the west. Its capital is Bujumbura...

.

Main tributaries are Ugalla River, Gombe River, Moyowosi River, Ruchugi River and Nguya River.