Floods are recurrent phenomena in Nigeria. Due to different climatic and rainfall patterns in different regions, it has been the experience that while some parts are suffering devastating floods, another part is suffering drought at the same time. With the increase in population and development activity, there has been a tendency to occupy the floodplains, which has resulted in the damage of a more serious nature over the years. Often, because of the varying rainfall distribution, areas not traditionally prone to floods also experience severe inundation. Thus, floods are the single most frequent disaster faced by the country.
Flooding is caused by the inadequate capacity within the bank of the rivers to contain the high flows brought down from the upper catchments due to heavy rainfall. Flooding is accentuated by erosion and silting of the river beds, resulting in a reduction of the carrying capacity of river channels leading to changes in river courses and obstructions to flow; synchronisation of floods in the main and tributary rivers; retardation due to tidal effects; encroachment of floodplains; and haphazard and unplanned growth of urban areas.
Nigeria experiences annual flooding, especially in its coastal areas, but this year’s floods are the worst in more than a decade. Authorities blame the disaster on the release of excess water from Lagdo Dam in neighbouring Cameroon, and unusual rainfalls.
After drought, flooding incidents affect most people across the continent, though they are concentrated in a few countries. Collectively, Kenya, South Africa and Mozambique experienced 75 per cent of the region’s floods and storms, while Kenya and South Africa were the most affected by drought.
Tragically, Somalia, according to a report, experienced the highest death toll from natural disasters due to its 2010 drought. Mozambique had the second-highest death toll, largely caused by Cyclone Idai that took place in 2019.
Water stress and hazards like withering droughts and devastating floods are hitting hard African communities, economies and ecosystems. Rainfall patterns are disrupted, glaciers are disappearing and key lakes are shrinking. Rising water demand, combined with limited and unpredictable supplies, threatens to aggravate conflict and displacement, according to a new report from the World Meteorological Organisation.
Records indicate that Cameroon and Nigeria were supposed to build two dams at inception, such that the Nigerian dam, known as Dasin Hausa Dam, planned to be constructed in Adamawa State, would contain the water released from the Lagdo Dam at any point in time.
The Dasin Hausa Dam was supposed to be two and a half the size of the Lagdo Dam, and also meant to supply electricity to the Northern part of Cameroon and aid irrigation. But sadly, the absence of dams to control the excesses from the Cameroon dam has continued to cause serious consequences on frontline states and communities along watercourses.
The nation’s floodwater is needed in Burkina Faso, Somalia, Sudan, Chad, Mali, Niger and Northern Nigeria, where drought, conflict and insecurity are driving water insecurity. According to a report, about 40 million children are facing high levels of water vulnerability.
Today, droughts and floods are a common feature and their coexistence poses a potent threat, which cannot be eradicated but has to be managed. The transfer of the surplus flood water to areas experiencing water scarcity in Nigeria is a potential possibility to solve both problems of flooding and drought. This would also help create additional irrigation potential, the generation of hydropower, as well as overcoming regional imbalances. The recurrence of drought and famines during the second half of the 19th century necessitated the development of irrigation to protect the failure of crops and to reduce large-scale expenditure on famine.
Therefore the African Union, Economic Community of West African States and World Bank should harness the construction of the Lagdo Dam, which started in 1977 and was completed in 1982, to solve the problem of sub-Saharan Africa which suffers from greater levels of water stress than many other regions in the world.
