Rivers and deltas

Rivers are lifelines in many dry regions of Africa. They provide the necessary water for agriculture, household uses, transport and biodiversity. They fill the wetlands of inland and coastal deltas with fresh water, thereby maintaining the inhabitant’s livelihoods and biodiversity of these dynamic areas.

What is a river?

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground and vanishes from the surface. Rivers originate as precipitation on high ground that flows downhill into creeks and streams. Water seeping out of the ground through saturated-soils adds to this volume. Together, these flows merge into rivers.

What is a river delta?

River deltas are found on the lower reaches of rivers, where the flow of water spreads out and slows down, depositing sediments into expanses of wetlands and shallow water. There are tow types of deltas: coastal deltas where the river meets the sea and inland deltas where the river fills extensive floodplains and marshes. One of the most famous African examples of an inland delta is the Inner Niger Delta in Mali.

The most important rivers of Africa are the Nile, which is Africa’s longest river, the Congo River, with the largest discharge on the continent, the Niger and Zambezi River. Their basins stretch out over a multitude of different countries, which often cooperate in international bodies, such as the Senegal Basin Authority (OMVS), Nile Basin Authority and Niger River Basin Authority.

Biodiversity

Rivers and deltas provide critical habitat for fish and other freshwater animals such as amphibians and mollusks. Thousands of species rely on healthy water flows for their survival. Even mammals depend on them, such dolphins and manatees.  

Livelihoods

Rivers provide the people with fish and water for their cattle and crops. They are also a major source of transportation and communication in Africa. Even in the case where rapids and waterfalls preclude the use of rivers for navigation, transportation routes are often developed along river valleys. Household uses of the fresh water are many, and in the extremely dry regions river water is often the only source of water for hygiene and sanitary uses.

Threats

Growing human populations and increased demand for water by industry and agriculture is reducing both the quantity and quality of available water in rivers. Furthermore, African rivers and deltas are subject to many existing hydropower dams. It is the continent with most plans for building new dams that will further limit the water flow.

Read more on our work on the Niger River and its deltas

 

Map of major rivers

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