The Great Wall of Lagos is formidable in its design and already does a magnificent job of protecting the coastline, even though it’s not yet finished.
Over the last 100 years, pounding waves from the Atlantic Ocean have eroded the land off Lagos, bringing the sea closer to the financial centre of Victoria Island. The threat of serious flooding was a major concern. Before the Great Wall, tidal surges used to regularly cause water and debris to spill over on to the main coastal highway – Ahmadu Bello Way.
Today the highway is clear from flooding, already protected, thanks to the development of Eko Atlantic.
Testing the Great Wall
Before the first of the giant concrete armoured blocks for the Great Wall of Lagos was lowered into position, its ability to withstand the worst of the Atlantic tidal surges was put to the test. Urban engineers at DHI, the world-renowned Danish hydraulic research centre, carried out extensive scale model trials. Data analysis by computer models showed that the Great Wall could withstand the worst expected storms over 1,000 years.
Facts and Figures on the Great Wall of Lagos
When it’s complete, the Great Wall of Lagos will be over 8 kilometres long. It is made from 100,000 concrete blocks (accropodes) weighing 5 tons each which interlock loosely to form an effective barrier that dispels the force of the waves and provides the primary armoured sea defence. Beneath the accropodes are various layers of rock that function as the secondary armour and core.
In the first quarter of 2013 the Great Wall of Lagos was passing the halfway construction stage at 3.5 kilometres in length and is growing at the rate of about 6 metres a day. In its completed form it will protect not only Eko Atlantic, but Victoria Island as well.
Creating the Foundations of Eko Atlantic
The Belgian company, Dredging International, a leader in this field of engineering, leads the sand-filling work. Dredging is operational around the clock. This massive undertaking is being carried out with great care and efficiency to reclaim land that our grandparents walked on as children.
By the time the work is completed, they will have moved 140 million tons of sand – that’s 95 million cubic metres.