GOTHENBURG: PROTECTION FROM FLOODING

To protect the city of Gothenburg from flooding and rising sea levels, two flood control structures are being planned. Gothenburg is the first city in Scandinavia to plan construction of outer flood barriers to protect an entire city.

Facts

Assignment: Outer flood barriers

Location: Gothenburg

Expertise: Climate change adaptation, architecture, civil engineering

Client: Gothenburg City Planning
Office

Assignment

Gothenburg has had several episodes of severe flooding in the past decade. A combination of rising sea levels and heavy precipitation are further exacerbating this risk.

Sweco has performed a feasibility study for how outer flood barriers can be designed to protect Gothenburg from flooding. The barriers will be built in the Göta älv river, one upstream by the Jordfallsbron bridge and one downstream by the Älvsborgsbron bridge. Sweco has assessed the most suitable solution for the project and calculated the costs for design, construction and long-term maintenance, which have been estimated at between SEK 10 and 20 billion. This is roughly equivalent to the cost of building the West Link railway infrastructure project.

Sweco has also previously been tasked with studying how to best protect Gothenburg’s waterfront buildings from flooding. One alternative was to build smaller barriers where the Säveån river, the Storahamn canal, the Moat and Kvillebäcken stream flow into the Göta River. Smaller barriers may need to be developed for the most vulnerable sections during the planning phase for the outer flood control structures.

Quote

"“Heavy rainfall can have major consequences for cities. This is something we have seen very clearly, for example in New Orleans and New York. A changing climate and the extreme storms it can cause are increasing the need for sound and reliable protection. By building the flood barriers in the Göta älv river, we can reduce Gothenburg’s vulnerability to extreme weather conditions,” says Mats Andréasson, Project Manager at Sweco."
“However, smaller barriers significantly reduce the feeling of water contact with the river. In view of this, our study found that large barriers by the Älvsborgsbron bridge and Kungälv river are the most profitable alternative. A large-scale solution protects extensive areas without affecting the city’s inner watercourses and will make it possible to continue building close to the water in the future,” says Mats Andréasson.