When volcanic eruptions led to the formation of the Virunga mountain range many years ago, Lake Kivu’s outlet towards the Nile was blocked. As a result, its content surged over the edge. The overflow created a new outlet and formed Rusizi River.
Massive tectonic movement responsible for the formation of Virunga mountains north of Lake Kivu erased one river from the surface of the earth and created a new one. The new river flows southwards into Lake Tanganyika, which in turn, feeds River Congo through Lukuga and Lualaba channels.
Rusizi River spans the distance of 117 kilometers. Along the way, it forms part of the border between Rwanda and the Democratic Republic of Congo (DRC). Farther downstream, it borders Burundi and the DRC.
As stated above, the volcanoes blocked Lake Kivu’s northern outlet towards Lake Edward. I always refer to the later as Lake Rutanzige but Ugandan authorities chose to honor King Edward VII instead.
Many attractions in this part of Africa are named after members of the British royal family, explorers and prominent figures in the Royal Geographical Society (RGS). These include Lake Albert, Lake George, Lake Victoria, Mount Stanley, Mount Speke, Queen Elizabeth National Park and Murchison Falls National Park.
There is a border post and a bridge connecting Rwanda and the DRC at the source of Rusizi River. While flowing towards the southern part of the Albertine Rift, the said river descents from 4,800 to 2,530 feet above sea level. Its steepest gradient can be seen within the first 40 kilometers of its course.
An investment consortium managed by the Economic Community of the Great Lakes Countries owns a couple of hydroelectricity plants along the course of this mysterious river. These power plants supply electricity to Rwanda, Burundi and the DRC.
Before gliding into Lake Tanganyika, Rusizi splits into several tributaries, forming a delta and riparian swamps. The streams are gentle at this point. In the 19th Century, Arab traders thought the river flows out of Tanganyika towards the opposite direction.
Uncertain of the actual direction of the flow, British explorers Richard Burton and John Speke pondered the possibility of Lake Tanganyika pumping water into the Nile via Rusizi and developed a preposterous south-north flow hypothesis.
Obviously, Burton and Speke hadn’t been to the northern part of the river yet. On this side, the direction of its flow is clearly noticeable. Powered by gravity, Rusizi storms downhill through stunning landscapes and slows down as it approaches Tanganyika. Its fresh water supports lives of a variety of creatures and drives turbines to inject additional energy into three economies.
From the source to the mouth, through gorges and falls, Rusizi River is like a book. You can read its fascinating story one page after another and one chapter at a time.
The author is a travel enthusiast on a tour of all 30 districts and 416 sectors of Rwanda. Follow his awe-inspiring expeditions on Twitter @GeoExposure