Dredging and Coastal Development

For decades, removing contaminated sediments through dredging has been restricted or prohibited in North America. The major concern has always been that dredging would resuspend the contaminated sediment in the water, spreading contamination and causing environmental impacts across even larger areas.

On June 19, the cruise liner Queen Mary II visited the Scottish Highlands, berthing at Invergordon on the Cromarty Firth. The week running up to the arrival of the QM2 was a time of excited anticipation by the townsfolk and fevered activity by the port authority. At 345m long, towering 60m above the waves and drawing 10m of water, the QM2 is the largest liner ever to sail the seas.

A wide range of digital geospatial technologies have long been used in the planning and management of ports, terminals and coastal zones. These technologies are becoming increasingly important as their capabilities increase, as their cost goes down, and as they become integrated via the World Wide Web. Their importance also increases with demands for safer, more efficient ports and terminals and for sustainable development along the world’s coasts. Interoperability among geospatial technologies and among different technology providers’ products has become a key requirement. In almost any geographic region, and especially in heavily populated regions, people working in different sectors, disciplines, agencies, jurisdictions, and professions have a need for efficient sharing and integration of diverse kinds of information about their region.

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.

CNOOC and Shell Petrochemicals Company Limited (CSPCL) is set to make petrochemicals history in China by building and operating a US$4.3 billion petrochemical complex. The construction of the petrochemicals complex in Daya Bay at the southern coast of China’s Guangdong Province started in 2002. The complex called for the construction of two marine facilities which involved a significant dredging scope of approximately 8 million m3 of clay.

Construction activities create a constant need for extensive disposal facilities for contaminated soil in the Copenhagen area. The land based disposal facilities are however limited due to drinking water interests and due to landscape values. At the same time there is a need of expanding urban areas for development and for e.g. new harbour facilities. Is it possible to construct confined disposal facilities seawards and subsequently use the reclaimed area for development?

The African Section of the Central Dredging Association (CEDA) will organise its second international Dredging Days in Tangiers, Morocco on the theme “Protection of the Coastline, Dredging and Sustainable Development” from 1 to 3 November 2006.

The Harwich Haven, in England, is formed by the confluence of the estuaries of the River Orwell (Suffolk) and River Stour (Essex) (see Figure 1). The area has a long maritime history, with the last century seeing significant development of port facilities, most notably at Felixstowe and Harwich.