KIVU, a considerable lake lying in the Central African (or Albertine) rift-valley, about 60 m. N. of Tanganyika, into which it discharges its waters by the Rusizi River. On the north it is separated from the basin of the Nile by a line of volcanic peaks. The length of the lake is about 55 m., and its greatest breadth over 30, giving an area, including islands, of about 1100 sq. m. It is about 4830 ft. above sea-level and is roughly triangular in outline, the longest side lying to the west. The coast-line is much broken, especially on the south-east, where the indentations present a fjord-like character. The lake is deep, and the shores are everywhere high, rising in places in bold precipitous cliffs of volcanic rock. A large island, Kwijwi or Kwichwi, oblong in shape and traversed by a hilly ridge, runs in the direction of the major axis of the lake, south-west of the centre, and there are many smaller islands. The lake has many fish, but no crocodiles or hippopotami. South of Kivu the rift-valley is blocked by huge ridges, through which the Rusizi now breaks its way in a succession of steep gorges, emerging from the lake in a foaming torrent, and descending 2000 ft. to the lacustrine plain at the head of Tanganyika. The lake fauna is a typically fresh-water one, presenting no affinities with the marine or “halolimnic” fauna of Tanganyika and other Central African lakes, but is similar to that shown by fossils to have once existed in the more northern parts of the rift-valley. The former outlet or extension in this direction seems to have been blocked in recent geological times by the elevation of the volcanic peaks which dammed back the water, causing it finally to overflow to the south. This volcanic region is of great interest and has various names, that most used being Mfumbiro (q.v.), though this name is sometimes restricted to a single peak. Kivu and Mfumbiro were first heard of by J. H. Speke in 1861, but not visited by a European until 1894, when Count von Götzen passed through the country on his journey across the continent. The lake and its vicinity were subsequently explored by Dr R. Kandt, Captain Bethe, E. S. Grogan, J. E. S. Moore, and Major St Hill Gibbons. The ownership of Kivu and its neighbourhood was claimed by the Congo Free State and by Germany, the dispute being settled in 1910, after Belgium had taken over the Congo State. The frontier agreed upon was the west bank of the Rusizi, and the west shore of the lake. The island of Kwijwi also fell to Belgium.

See R. Kandt, Caput Nili (Berlin, 1904), and Karte des Kivusees, 1: 285,000, with text by A. v. Bockelmann (Berlin, 1902); E. S. Grogan and A. H. Sharpe, From the Cape to Cairo (London, 1900); J. E. S. Moore, To the Mountains of the Moon (London, 1901); A. St H. Gibbons, Africa from South to North, ii. (London, 1904).