Reservoirs are artificially created or naturally occurring water storage ponds or lakes. They may even be the inlets of a dam constructed to store water. Reservoirs also occur underground, those below a water well or oil well. African reservoirs are used for irrigation and electricity generation purpose as these processes involve water utilization. They are also used for boating and other recreational purposes.
At times of droughts or low rainfall periods, the water in the rivers is insufficient to cater to the needs of the environment and people in Africa. Under such conditions, excessive water is released from these African reservoirs for the farmers to water their crops and also for residential and industrial purposes.
The African reservoir which is the world’s largest by surface is Lake Volta. It is created on the Volta River in the country Ghana. Lake Volta is fourth in the world in terms of the volume of water contained. The world’s largest reservoir by volume is also found in the African nation of Zambia and Zimbabwe. Lake Kariba is a reservoir formed in the basins of the River Zambezi.
Water in the African reservoirs are still due to the high concentration of sand, dirt, rock and other sediments. They sink to the bottom due to their weight which makes the water look quite clear, though the excessive sedimentation greatly reduces the total water level in the reservoir.
Two of the largest damns in South Africa are the Vanderkloof Dam and the Gariep Dam. The Vanderkloof is primarily used to irrigate areas and farmlands around it, expanding up to 100,000 hectares in the North Cape and Free State. It also contributes to hydropower and recreational projects of the country. The Gariep Dam is the main source of drinking water in the area and waters up to 22,000 hectares of farmlands.
The Albasini Dam, Albert Falls Dam, Alexandra Dam, Allemanskraal Dam and Alphen Dam are the few smaller reservoirs and dams found in South Africa. These African reservoirs have been established years ago fulfilling the water needs of most of the continent, though these dams are also found dry at times due to the low rainfall records in the surrounding states.
With the growing population today, the demand of water has increased in abundance over the last decade. Large ground water storage areas have been found in Northern Africa; in the sedimentary basins; and in Algeria, Chad, and Libya. The amount of water stored in these basins is equal to 75m thickness of water across the area, which is a considerably large amount.
Africa is believed to be sitting on vast reservoirs yet to be discovered. It is said that due to changes in the climate, the Sahara Desert had been converted into a desert centuries ago, under which reservoirs were filled with water around 5,000 years ago. Researchers believe that under many water scarce countries of Africa lie substantial groundwater reserves which are yet to be discovered. These African reservoirs can provide for the needs of the continent.