Geoparks Africa
World Heritage Sites

Kivu: Africa’s third deepest Lake which is also the deadliest

Lake Kivu, straddling both Rwanda and the Democratic Republic of Congo is usually not very much mentioned but this East Africa’s important water body features some rather amazing facts.

For instance, the regularly erupting Lake Kivu is both deadly and deepest, yet the Island on it happens to be the largest Lake islet in the world.

At a maximum depth of 480 meters, Kivu is the third deepest Lake in Africa, ranking on the 20th position globally.

However, with a mean depth of 240 meters; the lake ranks third in Africa but 13th globally.

The lake is therefore classified as a deep lake.

Now, the water volume of Lake Kivu is estimated to be 650 cubic kilometres, which places it in the fourth position in Africa by Volume and 17th globally.

Lake Kivu’s primary outflow is River Rusizi that empties its water into Lake Tanganyika and which further drains into the Atlantic Ocean through River Congo.

The lake is home to Idjwi Island which is the second largest Lake Island in Africa.

With an area of 340 square kilometers and a population of 300,000 residents Idjwi is also the ninth largest Lake Island in the world.

Lake Kivu is one of three known lakes in the world which experience Limnic eruptions, along with Lake Nyos and Lake Monoun lakes, both located in Cameroon.

These have been causing serious deaths during such volatile emissions.

Limnic eruptions, also known as a Lake overturns, are rare type of natural disaster whereby the dissolved carbon dioxide gases suddenly erupt from deep lake waters and forms a gas cloud capable of asphyxiating all living things in the proximity including wildlife, livestock, and humans.

As it happens, beneath Lake Kivu lies nearly 63 Cubic Kilometres of Methane Gas, reported to be the highest concentration of methane in the world in any lake.

The depth of Kivu contains nearly 256 cubic kilometres of Carbon Dioxide fumes.

Apparently, Africa’s current annual consumption of water is about 250 Cubic Kilometres; therefore if the Carbon dioxide beneath Lake Kivu was water then it would feed Africa for more than a year

On the other hand, if the Methane beneath Lake Kivu was to be burnt for one year, it would provide more than 100 gigawatts of power for the entire 12 months period.

For context, Kenya’s installed capacity is about 3,000 Megawatts (Around 3 Gigawatts) and so the above potential is nearly 30 times of Kenya’s installed capacity.

All these gases are as a result of the lake bed sitting on a Rift Valley which is slowly being pulled apart and hence volcanic activities.

Lake Kivu is classified as Meromictic, and this means that it has layers of water which do not intermix as a result of different densities.

In crude explanation, this means that the top water cannot filter to the base, and base water at the bottom of the lake cannot come up to the top.