Göteborg is a city on the west coast of Sweden founded in 1621 as a fortification against the Danish. To locate the city around marshes at the water seemed like a great idea, partly because of the difficulty for soldiers to cut through that kind of surroundings quickly without being discovered. Years passed and the once appretiated wetlands turned into landfill hosting shipping industry and other activities requiring stable ground. The result has been that the river Göta Älv is much slimmer than it once were.
Size of old inner city
Around the original fortification of the city from the 17th century lies marshland. The city is placed there for protection purposes.
The area Gullbergsvass on the Southern shore is now landfill. The Swedish word for reed is "vass".
The area Tingstadsvass and Ringön on the Northern shore are also landfill. The Swedish word for island is "ö".
Big shipyard industry in the central parts of town. The harbour moves to Eastern outskirts of the city.
The harbour expands even further and is now bigger than ever - the biggest port in Scandinavia. The former industrial sites in central parts of town are developed for housing as well as host for new business.
Nowadays we build mixed use residential areas in the former industrial sites along the river. To live close to the water is regarded highly attractive. However, to live close to the water can become quite a worry. The last years reports have had it that due to climate change the water is expanding and as a consequence the sea level rises. Gothenburg - built in a valley with clay ground - with the Göta Älv running through the city having an altitude difference of 44m to the water uptake area lake Vänern - situated in the meeting point between fresh and saline water - is in the respect a vulnerable city.
But climate change also brings with it more occasions of extreme weather events, which are more intense but also unpredictable. The rising sea level together with extreme weather events is what threatens big parts of central Gothenburg. Higher water levels threatens to damage not only the ground (land slide) and buildings, but also basic infrastructural systems such as roads, railroads, electricity circuits, fresh water uptake, greywater distribution and daywater distribution.
Geological conditions - The city floating on clay
The risk for landslide and erosion are high in Gothenburg, since it's literally floating on clay. But the fact that large part pf it's central parts are landfill of what used to be marshland makes the risk even higher.
Historical water edges and high risk flooding areas
The historical water edges coincide with the high risk for flooding.
Development areas and flooding areas
The current development plans coincide with high risk flooding areas.
Large areas in central Gothenburg lies under the current extreme water level. However, calculations by the Climate Group suggests that we can expect a sea level rise up to 2 meters within the next 100 years, and that’s calculating low.
Measurements taken along the water edge
Measurements show that the water level in Göta Älv is rising.
The site Frihamnen has changed throughout the years. Most of what we see today is landfill not only of Göta Älv river but also the canals Kvillebäcken and Tingstadsån. A bridge hasn't always connected the Southern shore, we can see it on the image of 1910.
The area can be said to have one old and one new part. The older one we see on the image from 1922 and is built with wooden poles. Those piers are called Southern and Northern Frihamnspiren. The area which is later added - Kvillepiren and Lundbyhamnen - is built with concrete poles of varied length.
Land lying under extreme water levels
The whole area lies low and will consequently be flooded even with todays extreme water level. When we add 0,5m, 1m or 2m the results are even worse. If the area is to be exploited the flooding issue has to be taken into consideration.
Frihamnen is one of the central areas which are threatened by high risk of flooding. It is also one of the next sites to be developed in the name of Älvstrandsprocessen (to build along the water front) and holds large potential. It cannot be considered as strictly land, since it’s built on the former wetland on poles.
To deal with flooding in not only the area but surrounding areas as well I suggest to reinstate the former wetlands. In that way the site works as a water barrier, but also taking care of the only land which is already there and stable: the poles.
Wetlands works as sponges with a long recharge time, but they can also clean water and soil and usually hosts species in abundance.
About the project
Under the pavement, a city (changed from Gothenburg edge transformation)
This project aims to from the ground up deal with the high risk for flooding facing the city of Gothenburg in Sweden. It works by revealing and lifting up poles today hidden, and to use them as constructional elements capable of facing the water - not protect against it, i.e. with a resilient attitude. By doing that one is introducing the river to its former self, but at the same time meeting the needs of the city of today.
* More energetic violent weather and its associated costs
* Greater demands on existing aging infrastructure
URBAN DESIGN PRINCIPLES
* Density, Diversity and Mix
* Pedestrians First
* Transit Supportive
* Complete Communities
* Integrated Natural Systems
* Redundant and Durable Life Safety and Critical Infrastructure Systems
* Resilient operations
BUILDING DESIGN PRINCIPLES
* Design and plan for low energy input constructability
* Design for future flexilibity of use
* Design for use of local materials and products
* Design and plan for low energy input constructability