Floating Fields 蛇口浮田 

Floating Fields is a productive pond-scape that doubles up as a leisure venue, demonstrating how architectural design can integrate concepts of aquaponics and algae cultivation, self-cleansing water cycle and sustainable food production. Premised on a vision for ‘Re-Living The City’, the project aspires to low-carbon urban living by creating enjoyable and engaging public space based on reinvigorating disused industrial architecture through an edible landscape.

The project was created by Thomas Chung, Associate Professor at the School of Architecture, The Chinese University of Hong Kong, with the algae cultivation co-created with Professor Ho Kin Chung’s Microalgae Research team, The Open University of Hong Kong, and Chi Fai Fung of SEED(HK) as overall agriculture consultant. Commissioned as the feature landscape component for the Shenzhen Hong Kong Bi-city Biennale of Urbanism\Architecture UABB (SZ) 2016 at the Former Dacheng Flour Mill in Shekou, the project’s venue and construction support came from China Merchants Shekou Industrial Zone Holdings Co., Ltd.

Background and context

Floating Fields, forming a major public space landscape responding to the biennale theme of ‘Re-Living The City’, comprises a self-cleaning, eco-water cycle of ponds supports floating farm plots, fish, duck, silkworm and microalgae cultivation, as well as filtering plants. The project draws from the site contexts, inspired by the operation and tradition of oyster cultivation using floating bamboo plots in Deep bay, while also reviving the roots of the water-based polyculture ecology (multiple agri + aqua-cultures) that once defined the unique territorial landform of the Pearl River Delta in Southern China.

In the past, inhabitants of the low-lying, flood-prone, delta landscape fused agriculture including silkworm, mulberry leaves and fish cultivation with inventive eco-engineering to evolve the Mulberry-dyke Fish-pond, one of the most celebrated examples of intensive eco-agriculture of the region. It engendered a once flourishing water-based commerce that has now all but vanished leaving abandoned landscapes. Likewise, this year’s biennale venue, Shekou’s former Da Cheng Flour Factory, is a product of Shenzhen’s rapid urbanization, a monumental effort that covered overnight the centuries-old wetland polycultures with concrete and industry to fabricate the instant flotation of the expectant metropolis. The obsolete factory, now cracking up to allow sunlight and overgrown wild blossoms to seep through to the water underground, testifies to the enduring resilience of nature.

Concept and design

The design operates on several levels to resuscitate the lifeless site. The presence of an existing covered waterway running diagonally through the site parallel and west of the oblong former factory dormitory spawned the idea to reintroduce the aquatic theme. The life-giving waterway is revitalized into a row of filtering ponds. The idea of a connected series of ponds holding various aquatic functions is extended around and outwards from the building. Their orientation, size and configuration derive from the structural bay rhythm and main entrances of the existing building, a linear block that has itself been converted during the biennale into a multi-use learning resource centre with exhibition, roundtable space, mezzanine library and a café restaurant.

Concrete ground east of the building is broken up to form larger ponds. Part of the rubble is crushed and recycled as gravel to fill pathways between ponds. The productive ponds are themselves formed from concrete bricks, and complemented with various pathways, platform and bridge with steps, benches and pavilions to create a walkable landscape combining food production and leisure.

Water cycle and floating plots

A complete ecological pond-scape wraps around the old dormitory. The self-sustaining water cycle begins with nutrient-rich ‘waste’ water fed into the algae pavilion’s ponds. Two types of colourful micro-algae are expertly cultivated in two ways by the Microalgae Research team from the Open University of Hong Kong to enhance the water purification. A specially designed three-step cultivation open pond sequence culminates in the harvest tank where the grown algae can be collected to ultimately produce organic fish feed, fertilizers and even biofuel.

Next comes a corridor of filtering ponds that purify the project’s waste water using filtering gravel and filtering plants as the filtering medium. Volcanic rocks, broken tiles, and coarse river sand make up the gravel, while the plants include Umbrella Grass, Powdery Thalia, Iris, Alocasia plant, etc.. Water trickles through the medium successively in a zigzag fashion to elongate the filtering distance. The water-based plants are chosen for both their filtering capabilities and their visual qualities, and can be viewed along the elevated brick bridge.

The ‘cleaned’ water then flows into the prominently placed water lily pond, through the koi carp pond and duck pond, into the big ponds where a contemporary version of the Mulberry dyke-Fishpond cultivation is combined with aquaponics. Edible fish and floating plots are surrounded by mulberry beds that are grown to feed cocoon-spinning silkworms inside a silkworm pavilion.

The floating plots return oxygen to the water while partially absorbing nutrients in it, before it is fed back to start of the cycle to the algae pavilion. The floating plot, inspired by existing flotilla of bamboo rafts that is part of the oyster cultivating tradition of neighbouring Deep Bay, is tested out within the ponds as light-weight, mobile farming plots. This latter idea is tested on different horizons, on water-bodies, filling pavilion roofs or on top of the converted dormitory. Part of the cleaned water is also used for rooftop plot irrigation.

Floating Fields integrates multiple cycles, wherein each pond can have two-way nutrient provision, waste water recycling, crop production, water purification and landscape features, creating more flexibility than conventional systems.  The connected pond-scape operates as a self-sustaining ecology to demonstrate a virtuous cycle of hybrid urban-agricultural environment that can also become at once a productive and leisure public space for the enjoyment of all.

Engaging the public

Besides the productive-leisure architecture-landscape hybrid of ponds, plots, paths and pavilions, Floating Fields generated events with great response and publicity from local community and media. At the Biennale ‘Opening Forum’, in the presence of all curators, international critics, architects and exhibitors, Floating Fields was a featured project in the discussion on notion of envisioning PRD 2.0. ‘Planting Day’ gave over 100 city kids and their families the chance to sow their own floating plots, catch fish and learn about duck, silkworm and algae life-cycles firsthand. ‘Tasting Festival’ supported by local CSA (Community Supported Agriculture) groups offered participants fish soup and salad rolls (harvested on site) with talks on urban agriculture and the potential of microalgae in architecture and urban ecology. ‘Harvest Parade’ at the Biennale Closing successfully harvested the first crop of floating plots, presented algae cultivation results, and included a forum “Envisioning urban agriculture and ecology for Bio-social living”.

Floating Fields was awarded the UABB (SZ) 2016 Organizing Committee Grand Prize. The jury commented that “Floating Fields is a landscape complex that constitutes an experiment and exploration entirely based on the curatorial theme of “Re-living” … not only reviving the unique ecological agricultural landscape of the Pearl River Delta, but also extends and transforms them into a unique public space that offers a pleasurable leisure experience.” Floating Fields has been exhibited as part of the “Post-industrial Urban Orchard: City after the City” in XX1 La Triennale di Milano 2016. The project is Winner of the World Architecture Festival (WAF) 2016, Berlin, Production Energy & Recycling – Completed Buildings Category.

Continuity and extension

To continue the project as a live experiment, a collaboration between the universities and parties involved is currently being planned. Besides further calibrating and refining water system to test an entire cycle of seasonal variations, it is hoped that Floating Fields will eventually become a multi-disciplinary laboratory and research node on sustainable design and green development. Using the site and Shekou as base and context, the intention is to engage in innovative research on topics such as bio-social design, architecture and urbanism; empirical research on water ecology and algae cultivation; and sustainable urban food production and its integration with the built environment.

Returning to fundamental urban re-living, disbanding excessive construction, and resuming a symbiotic space for nature, Floating Fields hopes to engender an innovative public space model that cultivates comforting nourishment and soothing experience amidst  the restlessness of our buoyant city.