The authorities should audit environmental plans to mitigate flooding disasters
The storm water dumped on Lagos by a recent heavy rainfall, accompanied by strong wind, has ebbed in most parts. But it has left desolation among those that were impacted adversely. A four-storey building under construction in Lagos Island collapsed, a boat travelling from Falomo to Badagry in the afternoon capsized and many vehicles that were submerged in the flood now have engine problems. The storm water also caused flooding in most parts of Lagos Island, particularly low-lying areas like Banana Island and Park View Estate, and environs in Ikoyi, Victoria Island, Lekki and Ajah, as well as Apapa, Ikeja, and other areas. The greater challenge is that the problem is not about to abate.
Ordinarily, heavy rainfall over a short period of time can cause flash floods, and moderate rainfall over several days can overflow rivers or dams. But Lagos is a low-lying coastal city that should drain itself naturally if the water paths are not blocked by the several buildings that line the banks of the Lagoon, canals, and drains. That principally accounts for why storm water floods the streets, homes, and other unlikely places. This is also a national challenge since flood risk is not properly considered in land-use planning, nor is it properly understood by people living in areas subject to low-probability, high-impact flooding events.
Annually, just before the rain sets in, the Lagos State government sends out its work gangs to clean up the city’s tertiary drains and canals and compel residents to clear out their primary drains. These water channels are usually clogged with solid waste dumped by some residents that are ignorant of the consequences. Interestingly, the state government knew the rain would come very hard this year. While presenting the Year 2021 Seasonal Climate Predictions in April, the Commissioner for the Environment and Water Resources, Tunji Bello, said there would likely be “days with extremely high rainfall, which may result in flooding.”
The government discussed with the Ogun-Osun River Basin Authority which has ensured control and monitoring of the steady and systemic release of water from Oyan Dam to prevent flooding downstream. It advised residents in communities in coastal and low-lying wetland areas of the state, to move upland when the need arises to avert needless loss of lives and property, promising to alert them at the appropriate time. But all these have been of little effects.
A lot of money has gone into Lagos’ drains. In 1984, the federal government took a $72 million loan from the World Bank on behalf of the state government to extend the primary storm drainage network of the metropolitan area to ameliorate wasteful and costly problems of flooding. The loan was repayable in 20 years. There was also an effort known as ‘Drainage Master Plan for Lagos State and Pilot Area Integrated Infrastructure System’, prepared by a company, Dar Al-Handasah Consultants/CIVTRA Consultants, an international consortium of professional service firms. It operates in Africa out of Cairo, Egypt, among others.
The company identified the storm water drainage problems in Lagos and developed surface water drainage systems in line with sustainable development and green storm water systems. They also proposed effective and economic mitigation and prevention measures. They then prepared a storm water drainage master plan and an environmental policy framework. The company said they went beyond their plans and provided hands-on support to fix part of Lagos State’s drainage system, providing the state with a life that is far less disrupted by floods. What the recent floods have shown is that the plan was not full proof.
We therefore urge the Lagos authorities to audit their environmental plans to mitigate flooding disasters that make the state not very habitable, especially during rainy seasons.