How Africa’s largest city in terms of population is staying afloat
The most populous city in Africa is also one of its most vulnerable to sea level rise and floods. To stay afloat, everything from its architecture to its transport may have to change.
The thronging streets of Lagos, Nigeria, is a challenge at the best of times. But during the rainy seasons, the city’s streets can become almost impassable. Home to more than 24 million, Lagos is Nigeria’s economic powerhouse, making it a destination for people seeking new opportunities. But that rapid growth creates pressure on the streets, and the environment.
The streets are often flooded, in part due to the dysfunctional disposal of the 6,000-10,000 tonnes of rubbish generated daily in the city. After a downpour, rubbish piles up in open gutters and makes moving around the streets difficult.
“I worry when it rains, especially when it is heavy,” says Lagos resident Stephanie Erigha. “It makes me anxious.” On one occasion when taking a taxi through a waterlogging-prone part of the city, she recalls the water gushing right into the back seat next to her.
While the overall climate in Lagos is expected to see less rainfall overall with climate change, the intensity of rain is expected to increase, bringing with it greater risk of flooding. Meanwhile, the low-lying city is also particularly vulnerable to water from another source: rising seas.
If global warming exceeds 2C, the city is predicted to see 90cm of sea level rise by 2100, according to research led by marine physicist Svetlana Jevrejeva, of the UK’s National Oceanography Centre.
How, in the face of flooding, blocked streets and rising waters, is Africa’s most populous city adapting?
Floating architecture: There is one part of Lagos that has extensive experience of dealing with high water. Much of the Makoko neighbourhood is not built on land, but rather sits on stilts above the waterline. Makoko, known as the “Venice of Africa”, is a labyrinthine slum built on stilts and navigated by canoe.
The slum has little access to electricity or clean sanitation, but it has also been home to innovations like the Makoko Floating School, a structure resting on recycled empty plastic barrels for buoyancy. The school’s pyramid shape helped lower its centre of gravity and so increase its stability, while also being an ideal roof shape for shedding heavy rains.