Africa’s richest natural resources are its rivers and lakes,
and over the years, there have been many proposed projects to harness the continent’s
immense water resources. One of the most talked-about is the Grand Inga Dam
project in the DR Congo, first proposed over 50 years ago. Inga is at the mouth
of the Congo river, where an immense drop in elevation plunges the water of the
Congo – the world’s second largest by volume, after the Amazon – with so much
force that that the hydropower potential generated is enough meet the
electricity needs of the whole of sub-Saharan Africa.
Another plan is to channel water from the Oubangi river –
one of the Congo river’s main tributaries – to replenish the waters of Lake
Chad, which have shrunk by more than 90% over the past 50 years. At 25,000
sq.km in 1963, Lake Chad used to be Africa’s fourth largest lake. But higher
evaporation rates in the arid Chad region – partly driven by climate change –
and increased water withdrawals from feeder rivers for cotton and rice
production have put increased demand on the lake, and it has dwindled to just
1,540 sq.km. The idea to divert part of the Oubangi’s water into Lake Chad was
first proposed in 1960s, but began to get international attention more
recently. It involves creating a retention dam at Palambo, upstream from the
city of Bangui, the capital of Central African Republic. Water from the dam would
flow by gravity through a navigable, 1,350 km man-made canal into the
Chari-Logone river system, the main feeder of Lake Chad that supplies 95% of
its water. This arrangement would check the encroachment of the Sahara desert
and act as a much-needed source of water for Sahelian communities – although
Lake Chad is subject to much evapotranspiration, it is not saline, and so is
one of the few sources of fresh water in the region.
Lake Kivu sits in a volcanic area between Rwanda and the DR
Congo, where carbon dioxide and methane from below the earth surface seeps into
the lake and lies quietly dissolved under 1,000 feet of water. But an earthquake or a lava flow could loosen the trap and
catastrophically release the gases, as happened in Cameroon in 1986, when a
deadly cloud of carbon dioxide from Lake Nyos asphyxiated over 1,700 people.
Under certain conditions, the newly released methane could even explode as it
hits the air. To avert danger, the Rwandan government has launched a grand
engineering scheme to suck up explosive methane from depths of 1,000 feet and
pipe it to a nearby power plant, generating 25MW of power. The Rwandan
government says the KivuWatt project could double the country’s electricity
production and reduce its dependence on imported diesel fuel that currently
powers a large share of its electricity.
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