Port of Gothenburg: Dredge spoil disposal system planned for fairway deepening project
In order to receive the world’s largest oceangoing vessels, the fairway leading into the Port of Gothenburg needs to be deepened by around four metres and six kilometres of fairway need to be dredged. Around 13.5 million cubic metres of spoils will need to be excavated and transported to a designated water area off the island of Vinga. An area which for many years has been used as a repository thanks to its depth and accumulative seabed.
The environmental permit application submitted by the Swedish Maritime Agency and the Gothenburg Port Authority to the Land and Environment Court in December last year includes a description of the envisaged dredging process. It also describes where the spoils will be deposited and how the spoils that are contaminated – around 285,000 cubic metres – will be stored optimally to safeguard the marine environment. The extensive inquiries and investigations that have been conducted include measurements of ocean currents at the seabed.
“We are protecting the marine environment by selecting a location with deep holes and where the seabed is characterised by accumulation, which means the spoils remain in place and will not be affected by the currents. In purely technical terms we begin by depositing the contaminated spoils and then covering them with about 10 metres of older, preindustrial mud and clay. The contaminated spoils will thus be capped and sealed,” said Kristina Bernstén, Sub-Project Manager Environment for Skandia Gateway at the Gothenburg Port Authority.
Detailed mapping of the area west of Vinga intended as a dredge spoil repository shows there will be no permanent long-term negative impact. This is indicated by previous deposition of spoils in the immediate area, including the Safer Fairway Project, run between 2002 and 2004 and with the same spoil volumes as in the Skandia Gateway project.
Factfile, Skandia Gateway
The Port of Gothenburg is the only port in Sweden that can receive the world’s largest vessels. However, at present they are unable to visit fully loaded. To resolve this problem and ensure favourable conditions for Swedish trade, extensive deepening of the fairway is required. The task of dredging the fairway and docks and the work required at the quayside are scheduled for completion by 2026. Skandia Gateway is a collaborative venture between the Swedish Transport Administration, the Swedish Maritime Administration, and the Gothenburg Port Authority.
Skandia Gateway film
The film shows the importance of a deeper port and the need to assure the future development and expansion of Swedish industry. The film explains the process of deepening the fairway from the current 13.5 metres down to 17.5 metres. Six kilometres of fairway will be dredged. At the Skandia Terminal, the existing facility and 1.2 kilometres of quays will be reinforced to allow two oceangoing vessels to load and discharge at the same time. The first phase of the Skandia Gateway project is due to be completed by 2026.
Source: Port of Gothenburg