'Copenhagen Islands' by Schønherr

As many other capitals around the world, Copenhagen is growing. In 2022 alone, new buildings in the capital area represented half of everything newly built in Denmark. Many of these projects were expensive dwellings, water facilities and cultural hotspots built close to the coastline and harbourfront. In Copenhagen living near the harbour is still reserved for the privileged, but the question is, if future investments are worth placing here.

Something is beginning to change. The surrounding nature and climate changes have begun to rock the foundations of the welfare capital of Copenhagen that, as all other cities around the world, has been created from the underlying and nearly forgotten landscape.

The situation we find ourselves in demands a thorough re-examination of the prevailing planning paradigms. The seas are rising, the groundwater table is rising, storm surges are pressing in, cloudbursts are becoming stronger and more frequent. Thus the structure of the ‘Finger Plan’ (editor’s note: Greater Copenhagen’s current planning principle) has fallen short. The historical, inner harbour and large urban areas will eventually be flooded by seawater, while other parts of the urban fabric will be swamped by rising groundwater. Rainwater, coming from large parts of Zealand, will lack the space required to be led out to the coast.

The historical, inner harbour and large urban areas will eventually be flooded by seawater

For the Venice Architecture Biennale 2023, as a part of the exhibition ‘Coastal Imaginaries’, Schønherr and a wide range of researchers present a new and alternative strategy for Copenhagen. ‘Copenhagen Islands’ is a research-based future scenario for a long-term and robust shift in direction for the capital, where the attention is turned towards nature and the city’s encounters with it. It is with nature’s own forces that we find the space to–slowly and over time–solve the city’s climate-induced problems and demographic challenges.

Over the next 100 years we must, step by step, change the city’s relationship with nature. The coast must be developed from being a physical and administrative line, to being a spongy zone that can absorb water when there is too much and release it when there is too little.

Copenhagen Islands is a vision. It does not contain any clear predictions of future population compositions or future mobility and infrastructure. We do not know if streams of climate refugees from the south will cause population growth to increase wildly. We do not know how we will control or transport our goods in the future. However, we can predict that the critical infrastructure, based on climate protection, will be as important for the development of the liveable city as roads, streets and electricity are today. In this regard the inherent forces of the landscape are our greatest allies.

Major Challenges in Planning for Natural Resilience

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To create a vision, one must identify the challenges. Copenhagen Islands is not the answer to a problem, but rather a new question, based on a series of investigations under themes such as topography, growth, value, infrastructure, and social balance:

Topography

Copenhagen was originally built on islets and flat land. Over time, technological land reclamation has made the land less dependent on the underlying landscape. Climate change is now challenging the technological premises on which the city’s development has been based over the past several years.

Can the city regain the connection with the underlying landscape?

Growth

Since 1600, the city has continuously expanded into the sea, on reclaimed seabed and in drained marshes and bogs – even though these areas are exposed to rising sea levels, storm surges, cloudbursts and rising groundwater. Urban development with a vision for a much longer future lifespan is needed.

Can the existing expansion strategy be reversed?

Climate

Storm surge water levels can rise to 5m around Copenhagen by 2100. Along the coast, the rainwater from Copenhagen’s large hinterland is drained in relatively few points. When the sea level rises, the rainwater will flow more slowly, and instead pile up along the flow paths. Increased rainfall and less pumping of drinking water causes the high levels of ground water to rise even further, at the same time as the rising sea water pushes into the subsoil from the coast.

Where do we find space for the rising sea water, groundwater, and rainwater?

Value

50% of all real estate investments in Denmark, were placed in the capital city area in 2022. The city contains many important functions, cultural heritage, housing for 1/3 of the Danish population and critical infrastructure – many of which are threatened by climate change, and some will be more expensive and complex to protect than others.

Which values are absolute in a long-term perspective?

Infrastructure

Road traffic will increase by 160% between 2020 and 2040. The motorway network around Copenhagen has been continuously expanded, the traffic load has followed suit, and the congestion is only increasing. Many of the major traffic arteries are in Copenhagen’s green areas. This fragments the biological connections within these large natural areas and at the same time destroys the enjoyment people experience here, with noise, air pollution and poor access conditions.

Should grey infrastructure still dominate the green in the future city?

Equality

In the past 10 years, the gap between rich and poor has risen by 27% in Copenhagen. The rising sea levels have very uneven effects on the various municipalities. The poorest municipalities are generally the lowest in the terrain, on the poorest soils, and will be hardest hit by rising sea levels. The richest municipalities are generally located at the highest point in the terrain and will be least affected.

How does a welfare state share the costs and benefits of climate adaptation?

Nature-Based Design Principles

The natural engineering methods behind Copenhagen Islands are what professionals call nature-based climate adaptation. The plan is, roughly speaking, based on seven methods identified by researchers Anna Aslaug Lund – Landscape architect and assistant professor KU, Gertrud Jørgensen – Architect and professor KU, Ole Fryd - Urban planner and associate professor KU, Iisa Eikaas - Architect and PhD student KU.

The seven methods can be combined in countless, hybrid forms and can be interpreted as tools for climate adaptation in completely different parts of the world, societies and with nature types different from those we know in Denmark.

Principle #1: Retreat

where on earth we live, we all–politicians, city planners, developers, and ordinary citizens–must first of all recognize the necessity of the method, which is all about the retreat of the city from the water. ’Retraction’ is climate-adapted urban planning, which develops the city by gradually–over several years–phasing out buildings in flood-prone areas, and creating new districts and densifications of existing suburbs in safer and higher-lying areas in the hinterland, i.e. the exact opposit

Principle #2: Wetlands

Instead, we must make way for the development of coherent WETLANDS and different landscape types. These can form a water-absorbing ’sponge’ that ranges
from salt marshland (for example from Kofoed Enge south of Dragør), over the re-establishment of former bog landscapes (which we have allowed ourselves to build on), to dense mangrove forests that, with the trees’ tightly tangled roots in the transition zone between land and water, ease the pressure from both storm surges and rising water levels in the form of both salt and freshwater.

Principle #3: Elevations

We can protect the districts and cultural landscapes that we decide to preserve through local ELEVATIONS, where the terrain is raised and shaped as a protective barrier around an existing building. Contrary to narrow, high dykes as we know them from the Dutch ’bathtubs’, the uplifting of the land is part of a wide and naturally shaped earth fill, and an integral part of the accessible nature of the area.

Principle #4: Aquatic Urbanism

In the areas where, for various reasons, we still want to build and live close to the water, we must develop an architectural typology that can be called AQUATIC URBANISM, where houses on stilts and columns will stand above the city’s coastal landscapes and wetlands, and where floating residential structures follow changing water levels.

Principle #5: Dunes

Along the coastal zone, DUNES are established and protect against the rising seawater and erosion. Dune landscapes are formed through the continuous feeding of the beach with sand, or through conscious control of where the sea’s natural sediment transport is deposited–in the Netherlands this is called a ’sand engine’. In this way, nature’s own dynamics are used to create wider beaches and higher seabeds.

Principle #6: Barrier Islands

Off the coast, barrier islands can be established, these are islands of sand and stone that form outside the coastline and which, together with underwater rock reefs, act as buffer zones against storm surges as they both lower the speed and height of the waves. Rock reefs, together with the planting of large eelgrass forests under the sea surface, will create significantly better conditions for life in Øresund and the marine nature park, which could become Copenhagen’s most beautiful neighbour.

Principle #7: Floodplain Livelihoods

In the wide zones between land and water, floodplain livelihoods can arise, where aquaculture, wetland agriculture and pond systems can supply Copenhageners with mussel and oyster farms, seaweed and many other foods that we will see much more of in the future. The delta landscapes, like other wetlands, can also absorb groundwater, rainwater and seawater, and protect the residential areas behind them from flooding.

By reading the landscape in this way and using it as a tool for urban climate adaptation, we are, in short, reuniting Copenhagen with its displaced landscape, its forgotten foundation.

Three Key Visions for a Resilient Capital

Copenhagen’s coastline, beaches, creeks, streams, and lakes together form a rich ecosystem which is the foundation for the city’s very existence. The city was originally formed on the basis of the laws of nature which demonstrate that water flows both downwards and at the same time forms part of an osmotic and fog-saturated system of groundwater, seawater and rain.

The city of Copenhagen is low-lying and large parts are built on sandbars, islets and filled seabed areas in the Baltic Sea. From the island’s large hinterland, Zealand, rainwater seeks the sea through a fine meshed delta crossing the entire city of Copenhagen.

The coast must be developed from being a physical and administrative line, to being a spongy zone

From Coastal Line to Coastal Zone

The coastline must be developed from being an administrative line, to being a spongy zone that can absorb water when there is too much and release it when there is too little.

In this wide coastal zone areas are returned to the habitat types they once were, such as marshes, salt meadows, swamps, rock reefs and eelgrass forests that must break the waves, absorb CO2, provide large recreational areas for both people and animals, and at the same time protect the city from storm surges and flooding.

Growing Green Interspaces

The world’s most compromised connection is that between nature and culture. You cannot run from one and choose the other without perishing. Nature is our lungs, just as the city is our heart chamber. The city is a mind-boggling network of contradictions and interlinked dependencies. Like a root zone network in a forest, tangled together with civilization’s widely branched, digital data.

The Finger Plan’s current green interspaces must, together with the reopening of Copenhagen Islands’ delta of watercourses and flow paths, grow and make room
for the bogs and marshes, forests and grasslands which today are completely on their way out of the Danish landscape. Nature in and around Copenhagen must be given space completely in its own right. Copenhagen residents can then visit these landscapes while respecting their delicate ecosystems. Slowly they will get to know the individual parts of nature, overcome their plant blindness, become friends with the ants, and recognize the existential community.

Polycentric Urban Structures

With this vision, a viable city is created where we plan based on a closer connection to nature, in a polycentric urban structure based on the new opportunities that arise in the periphery when we let water take the space it needs.

Over time, the city retreats to the hinterland, what is today called the suburbs. Along the green edges of the delta, the suburbs are densified with new urban developments and homes, closer to nature and with their own cultivation possibilities.

Copenhagen’s exit zones must gradually be converted into broad zones of ’natural sponges’, while in other areas buildings must be built differently and in harmony with the water when the building mass is rebuilt–raised on stilts, built on landscape islands or with open ground floors where water can freely pass underneath.

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From Schønherr’s project ‘Copenhagen Islands’ – a contribution to the exhibition 'Coastal Imaginaries' in The Danish Pavilion at the Architecture Biennial 2023 in Venice, curated by Josephine Michau, CEO and founder of CAFx.

'Copenhagen Islands' is also presented in CAFx' current window exhibition 'Coastal Imaginaries – Currents from Venice to Vesterbro', a small scale satellite of the exhibition in Venice with a local focus. On display at CAFx Halmtorvet 27 until 31 July 2023.

Download the entire catalogue 'Copenhagen Islands' by Schønherr‍

Text and illustrations by:
Rikke Juul Gram, Sanne Slot Hansen, Sofie Yde, Signe Winther, Thomas Hjort Vesterbæk and Stine Jørgensen, Schønherr

With input from:
Anna Aslaug Lund, landscape architect and assistant professor KU, Gertrud Jørgensen, architect and professor KU, Ole Fryd, urban planner and associate professor KU, Iisa Eikaas, architect and PhD student KU, Aart Kroon, geologist and professor KU, Karsten Arnbjerg, environmental engineer and professor DTU, Holger Bisgaard, urban planning consultant and Nils Drønen, coastal engineer DHI

Project commissioned by:
Curator Josephine Michau

Commisioner of The Danish Pavilion, Biennale di Architettura di Venezia 2023:
Danish Architecture Center

Funded by:
Danish Ministry of Culture, Realdania, The Danish Art Council

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