Sponge City

“Future cities will be “new garden cities,” emitting low or no net carbon, productive and conservation-minded. Rainwater will no longer be discharged from municipal pipes but will be retained in local ponds and supplement groundwater. Green spaces will be full of crops and fruit trees, instead of ornamental flowers and fruitless trees. Rice and broomcorn will ripen in the fields of communities and schools. In the harvest season, animals and humans will take pleasure together. Architectural surfaces will support photosynthesis. The roofs will be fish-raising ponds, with the functions of heat preservation, energy saving, and food production. Cellars will be great mushroom factories.”1

This is how the future metropolis is described by Kongjian Yu in his essay "Big Beautiful Feet."

Kongjian Yu is a Chinese landscape architect and urbanist - the author of numerous works and a supporter of ecological urbanism. Yu is the founder of Turnscape and a proponent of the Sponge City concept.

The idea of a sponge city, in various forms, is spreading all over the world. This principle is used by green movements that promote the development of green infrastructure and reducing the impact on nature. The sponge city (and more broadly, the sponge planet) represents a natural way to save and restore the global ecological infrastructure. It is a model of city construction that copes with floods, torrents, and other natural events during the rainy season with natural drainage systems.

The sponge city principle implies the restoration of the natural hydrological balance under the conditions of urbanization. We are constantly disrupting this balance with gray infrastructure, massive use of concrete, channeling of rivers, and construction of dams.

Asphalt and concrete, which are widely used in urban construction, do not carry rainwater and contribute to its accumulation. This causes floods and landslides. In contrast, sponge-like systems and permeable zones prevent water from accumulating on solid surfaces. Green areas, forest-parks, lakes, rivers, and streams perform the function of such a sponge for the city.

Kongjian Yu's flood control process resembles the sponge principle. A natural riverside wetland, like a sponge, can absorb water during floods and act as a water reserve during droughts.

For a long time, Kongjian Yu's ideas were viewed with skepticism in China, until the 2012 floods made the authorities see the need for radical change. Following this event, a wave of pilot projects for mass landscape renewal began in China, making the concept of the "sponge city" a reality.

For example, a barren area in the middle of the city of Sanya (a tropical tourist city on the Chinese island of Hainan) has been transformed into a place of harmonious coexistence of nature and people, where the ocean meets fresh water and natural ecological processes promote the regeneration of mangrove forest.2 For decades, Sanya's landscape has been pushed to the edge of devastation by inconsistency in development.

Water pollution and construction of embankment dams have destroyed the mangrove forest. In 2015, the city government decided to take a dramatic step and commissioned landscape designers to design Sanya's Mangrove Park.

The Turnscape team has developed a multi-level concept with the main principle: form follows processes! Ocean waves break through the finger-shaped landscape towards the park, which serves to prevent flooding. Using the resources available in the area, water channels were cut and flora and fauna were restored along them. Terraces help channel rainwater from the urban landscape and create public spaces at different levels. The Turnscape team has developed a multi-level concept with the main motto: Just three years after the construction of the park, the mangroves in the closed fingers rejoiced, and the species of fish and birds revived the environment. The park has become a daily recreational space for local communities and a demonstration of ecological regeneration that improves not only the natural environment but also public welfare.

We should expect many more floods, storms, droughts, diseases, the extinction of many species of animals and plants, and other changes as a result of anthropogenic climate change on Earth. To survive, we must adapt and shift our approaches radically. Landscape architecture plays a special role in these transformations. One of these changes could be ignoring the aesthetics that are comfortable for us in order to make friends with the natural landscape and to recognize it.

Landscape architecture of the future is regenerated and "restored" nature, parallel to urbanization. Even further, according to Kongjian Yu's vision, the city of the future is a garden in itself.

The article is prepared by U- Magazine. 
U- is an online publication that explores architecture and context; the purpose of the zine is to develop a Georgian-language database with an overview of urban and architectural theories. The magazine offers essays on the history of architecture, urban culture, and, most crucially, translations of works by important foreign language authors. U- is a free platform that examines ideas and theories of different times; it allows authors to investigate and share issues that are relevant to them.

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