Tipping point: The price of a cubic metre of sand

Authorship

Constantijn Dolmans, Secretary General, International Association of Dredging Companies, The Hague, The Netherlands

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The race to the top to be the biggest, best, most efficient, high tech world port is on. From Rotterdam to Los Angeles/Long Beach to the Far East, world class ports are adding container terminals and berths, lengthening their quays, and deepening their access channels. This year, for instance, Shanghai will overtake Singapore as the largest port in the world, at least based on freight volume. In 2005 Shanghai’s freight volume will most likely surpass 450 million tonnes – just another confirmation of the growin importance of China as a manufacturing and trading nation. Shanghai, however, has a problem, not unlike the problem that threatened to limit the competitiveness of New York harbour: It has a shallow entrance. Currently the approach channel at the mouth of the Yangtze River is only 8.5 metres. The larger container ships need a channel of at least 12.5 metre deep. Presently these larger ships have to wait for high tide to enter and leave Shanghai port, and that, of course, lessens the accessibility and thus the competitiveness of the port. This is the reason that, as a container harbour, Shanghai is still only number three in the world, after Hong Kong and Singapore. What to do? Deepening the shallow entrance of the harbour to 12.5 metres does not seem to be a realistic option. And so the Chinese government is investing heavily to construct a deep water port – Yangshan Port – some 60 km to the north of the Yangtze River estuary. Looking at these ports from the perspective of the International Association of Dredging Companies (IADC), it is clear what is needed: Maritime construction and dredging. Dredging and maritime construction, which support port expansion, are essential ingredients in port management.

Dredging companies and port authorities have an almost symbiotic relationship. Many ports could not exist without dredging, and without ports and harbours there would be less dredging going on in the world. What the IADC tries to accomplish is to encourage ports to get the dredging companies involved at an early stage, in the long-term planning for the development of the ports. Dredging companies have in-depth knowledge about matters like where sediments will be deposited by ocean flows, or how exactly discharging rocks in the water can prevent erosion. Their knowledge of water flows, erosion and sedimentation is all based on extensive scientific calculations. Dredgers often feel that port authorities, in order to take full advantage of their knowledge, and also of their problem-solving capabilities, should talk to them in the earliest stages of the planning.

What do dredgers really do?

The dredging industry often wrestles with public perception problems. To many people, dredging means clearing away the sediments from rivers, canals, lakes, ports and harbours. Dredgers keep the arteries of the world of trade unclogged, to use a medical metaphor. This is called maintenance dredging, an important activity, but it constitutes less than a quarter of what keeps dredgers actually busy, worldwide. People often also know that dredgers are involved in coastal protection; they have seen beach replenishment in progress. However, coastal protection at this time represents less than 10 percent of the dredgers’ activities. Because of the threat of tsunamis and hurricanes, and because of the rising sea levels, as a result of global warming, this 10 percent may well become higher in the near future. What then constitutes the other 65 percent of dredging activities? It consists of land reclamation and harbour extension, urban development of coastal cities, offshore constructions and LNG-harbours for supplying energy to the world. So dredging is often related to the expansion of a port, be it a seaport, a river port or even an airport. By now, there are quite a number of airports that have been built on artificial islands, or on other new land that used to be water. The best examples are those done in the Far East, in Singapore, Hong Kong and Japan. Compare an old map of Singapore with a recent one, and you can see: The eastern side of Singapore Island has grown. Where Changi Airport now stands, that used to be water. And also to the south the shape of the island has changed, there are land extensions to accommodate the expansion of the harbour.

Another example: When you fly to Japan and land in Osaka, you arrive at Kansai International, an airport built on an island in Osaka Bay. Kansai was the first artificial island airport in the world. It dates from 1993. A second runway is being built at this very moment. Of course, Schiphol Airport in the Netherlands is also located where there used to be a lake, but that is a rather ancient story. The Dutch have developed all kind of future plans to build a new large airport in the water to replace Schiphol, either on water lying to the east of the city of Amsterdam or in the North Sea, to the west of the city. Both JFK and La Guardia airports in New York City are, at least partially, built in the water. Australia is also fully participating in this trend: Sydney Kingsford-Smith Airport is partially built in the water, and so is Brisbane International.

Turning to South America, there is a plan to build an artificial island in the Rio de la Plata, to accommodate a new airport for Buenos Aires. The working title for that island is Aeroisola, and a number of private dredging companies are involved in the feasibility study for this project. There also seems to be advanced plans to build an international airport a half kilometre offshore from north Tel Aviv but it will demand significant environmental studies.

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