The name "Kivu" dates from at least 1914, when the colonial government divided Congo into 22 districts.
In 1935, the districts were grouped into 6 provinces, each named after its capital.
Costermansville Province was renamed "Kivu Province" in 1947.
Kivu was the name for a large "Region" in the Democratic Republic of Congo under the rule of Mobutu Sese Seko that bordered Lake Kivu.
It included three "Sub-Regions" : Nord-Kivu, Sud-Kivu and Maniema, corresponding to the three current provinces created in 1988.
The capital of the Kivu Region was in Bukavu, and the capitals of the three Sub-Regions were in Goma, Uvira and Kindu.
The whole Grand Kivu region has a surface of 230,510 km² (89000 sq miles); about 1/10th of the whole Democratic Republic of the Congo.
Comparatively to the USA, the Grand Kivu region is more than half the size of the state of California, about 7 times the size of Maryland or twice the size of Virginia. Only 11 states of the 50 in the USA are larger than the Grand Kivu region.
As a Lake, Kivu is one of the Great Lakes of Africa : 2700 km² (1040 sq miles) and stands at a height of 1460 metres above sea level.
It lies on the border between the Democratic Republic of the Congo and Rwanda.
Lake Kivu empties into the Ruzizi River, which flows southwards into Lake Tanganyika.
The lake bed sits upon a rift valley that is slowly being pulled apart, causing volcanic activity in the area, and making it particularly deep, its maximum depth of 480 m is ranked fifteenth in the world.
The lake is surrounded by majestic mountains.
The world's nineth-largest inland island, Idjwi, lies in Lake Kivu. With 285 km² (110 sq. miles) it is also the second largest inland island in Africa after the Ukerewe island in Lake Victoria.
The settlements on its shore include Bukavu, Kabare, Kalehe, Sake and Goma in Congo and Gisenyi, Kibuye and Cyangugu in Rwanda.
Native fish include species of Barbus, Clarias, and Haplochromis, as well as Nile Tilapia.
Widespread armed conflict in the surrounding region from the mid-1990s resulted in a decline in the fisheries harvest.
Lake Kivu is one of three known exploding lakes, along with Cameroonian Lake Nyos and Lake Monoun, that experience violent lake overturns.
Analysis of Lake Kivu's geological history indicates a periodic massive biological extinction about every 1,000 years.
The trigger for lake overturns in Lake Kivu's case is unknown but periodic volcanic activity is suspected.
The gaseous chemical composition of exploding lakes is unique to each lake; in Lake Kivu's case, methane and carbon dioxide due to lake water interaction with a volcano.
The risk from a possible Lake Kivu overturn would be catastrophic, dwarfing other documented lake overturns at Lake Nyos, since approximately 2 million people live in the lake basin.
Scientists hypothesize that sufficient volcanic interaction with the lake's bottom water that has high gas concentrations would heat water, force the methane out of the water, spark a methane explosion, and trigger a nearly simultaneous release of carbon dioxide.
The carbon dioxide would then suffocate large numbers of people in the lake basin as the gases roll off the lake surface.
It is also possible that the lake could spawn lake tsunamis as gas explodes out of it.
The risk posed by Lake Kivu began to be understood during the analysis of more recent events at Lake Nyos. Lake Kivu's methane was only originally thought to be a cheap natural resource for export and the generation of cheap power. Once the mechanisms that caused lake overturns began to be understood, so did the risk the lake posed to the local population.
An experimental vent pipe was installed at Lake Nyos in 2001 to degas the deep water, but such a solution for the much larger Lake Kivu would be extremely expensive, running into millions of dollars.
No plan has been initiated to reduce the risk posed by Lake Kivu.
Lake Kivu has recently been found to contain approximately 55 billion cubic metres of dissolved methane gas at a depth of 300 metres.
Extraction of the gas is currently being done on a small scale.