Will a giant bird-shaped sea wall save Jakarta?
It’s sad but true. Many parts of Jakarta, the capital city of Indonesia are sinking at an average rate of 7.5 cms each year, say geodynamic experts. That’s exponentially more than ten times faster than Venice, already famous the world over as the ‘City of Water. At present around 40% of the capital city is below sea level. By the end of this century Jakarta is expected to sink another 5 to 6 metres.
Much of the city’s ground water has already been extracted , either legally or illegally, for providing water to the inhabitants, thus hastening the sinking to dangerous levels. Each year around half of Jakarta’s population has to put up with heavy flooding around January, the peak of the rainy season. That’s when tens of thousands of hapless citizens have to be temporarily relocated. In 2007 and 2014, massive floods led to flooding of the city with muddy, highly polluted water. The catastrophic floods had risen to a height of around 13 ft and led to scores of deaths.
As a flood prevention measure and also to undertake major urban development plans, the government decided to implement the ambitious National Capital Integrated Coastal Development (NCICD) masterplan, commonly called the Giant Sea Wall.
Under this land reclamation plan, the biggest sea wall in the world – around 40kms long and 24 metres high – will be built in the bay north of the city. A chain of 17 artificial islands will be formed in the lagoon by the construction of the wall. Housing facilities, offices, malls and a new airport will be built on this reclaimed land. Around one third of the sea wall will be above water level and the entire structure will be in the shape of a garuda, the mythical bird that is the national emblem of Indonesia. The cost of the project? Around $40 billion!
The first phase of construction started in 2014. The entire project which is a joint venture between Indonesia and the Netherlands is expected to take 30 to 40 years to complete.
Environmental damage expected
Many experts are concerned that the project could be an environmental disaster. Indonesia’s Maritime Affairs and Fisheries Ministry has warned that the plant and animal life in the ocean as well as in the artificially created lagoon will be destroyed, the livelihood of fishermen adversely affected, beaches eroded, and the impact of storms too could be even greater.
Christophe Girot, professor at the Swiss Federal Institute of Technology professor has been reported to have said that implementing the Giant Sea Wall project would be like treating only the symptoms, not the cause.
Sea walls elsewhere in the world
Ancient coastal cities too were known to have constructed barriers as protection against the waters of the sea. Now with sea levels rising alarmingly due to global warming, many countries have taken recourse to building protective sea walls. The U. S. government built levees and flood walls to protect New Orleans, the Dutch have huge dykes across their country, South Korea has built the Saemangeum Seawall, and in London there’s the Thames Barrier.
The question is, will such sea walls be of much use in case of a massive tsunami or anything similar? They didn’t work for Japan where they’re now going to build a much higher and longer wall. Will rising ocean waters lead to more coastal cities requiring protective barriers?
Climate scientists have already predicted that the cities that face the greatest threat of damaging floods in future due to global warming include my own city of Mumbai, and the city I love, New York – which also consistently ranks among the top ten cities in the world in terms of international tourist arrivals.
By Veena Patwardhan