Shanghai Houtan Park
Landscape Performance Benefits
- Cleans up to 634,000 gallons of polluted river water daily, improving the water’s quality from Grade V (unsuitable for human contact) to Grade II (suitable for landscape irrigation) using only biological processes.
- Increased the biodiversity of the site dramatically, with 93 species of plants and over 200 species of animals observed.
- Sequesters an estimated 242 tons of carbon annually in park’s extensive wetlands, perennial plantings, and trees.
- Successfully demonstrated state-of-the-art design and construction techniques, resulting in 8 national design patents and 20-30 subsequent ecological water purification projects that employ the techniques created for Houtan Park.
- Provided recreation and educational opportunities to some 590,500 visitors during the 2010 Shanghai World Expo. The park continues to provide these benefits to city residents and visitors from around China and the world.
- Saves $116,800/year in water costs at the adjacent Expo Park where 264,000 gallons of water treated by Houtan Park’s wetland purification system is used in the water features.
- Reduced waste and saved an estimated $17,300 by reusing 37 tons of steel and roughly 34,000 post-industrial bricks found on the site
At a Glance
Former Land Use
Pudong, Shibo Avenue
Built on a former industrial site, Houtan Park was created for the 2010 Shanghai World Expo to demonstrate green technologies to the influx of visitors and remain as a permanent public waterfront park. The park was designed as a regenerative living organism that treats polluted river water, mitigates urban flooding, and increases habitat and biodiversity, while celebrating the regional culture and beautifying the riverfront for public use. Houtan Park unfolds along the Huangpu River through several linear miles of natural and constructed wetlands that clean the polluted river water and encourage native fauna to return. Throughout the park, several reclaimed structures reveal the site’s industrial past, while terraces planted with a variety of traditional crops give reference to the country’s agricultural heritage.
- A linear constructed wetland winds through the center of the park. At one mile long and 16.5-100 feet wide, the wetland works as a living machine, treating contaminated water from the Huangpu River. The different cleaning system stages include: a 650-ft long stonewall waterfall, terraced fields and a “U” pipe connection that trap pollutants, an 850-ft long area of plants selected to adsorp heavy metals, an 820-ft long area of plants selected for nutrient removal, an 820-ft long area of cacading terraces for aeration, and a 980-ft long water stability and sand filtration area.
- The terrace design also resolves the 18-ft change in elevation from the road to the shoreline, creating a quiet valley that allows people to access the water and enjoy views from numerous platforms and thresholds.
- Inspired by China’s agricultural fields, the terraces contain an abundant mix of crops and colorful native perennials like rice, sunflowers, and clover, which provide seasonal interest and opportunities for visitors to learn about Shanghai’s agricultural heritage.
- Riprap replaced the existing concrete floodwall, allowing native species to develop along the river’s edge while protecting the shoreline from erosion.
- Reclaimed steel from the site was used to create the steel arbor and shade structure, the ‘hanging garden’, and architectural details, invoking the site’s industrial past.
- The meandering valley along the wetland creates a series of thresholds creating visual interest and refuge within the bustling world exposition with opportunities for recreation, education, and research.
The 3.25 miles of pedestrian walking paths form a main loop with perpendicular boardwalks that bisect the wetland. Multiple footpaths through the terraces give visitors access to the inner spaces of the living landscape. The ecofriendly boardwalks are made of decomposable bamboo.
- Platforms and defined areas like the ‘hanging garden’ and a floating landscaped dock were designed as nodes on the pedestrian network and create areas where small groups can gather.
- 585 trees, including metasequoia, willow, privet, and camphor tree were planted throughout the park. Groves of bamboo and Chinese Redwood trees act as screens along the pedstrain paths and create ‘rooms’ that are used to exhibit modern art and industrial relics.
Houtan Park was built to showcase sustainable technologies for the 2010 Shanghai World Expo, themed “Better City, Better Life”, and then transition to a permanent waterfront park. One of the most salient challenges was to restore the degraded landscape to create a safe and pleasant public space. The brownfield site had been used as a landfill and storage yard. The water of the Huangpu River was highly polluted, considered unsafe for swimming and recreation, and devoid of aquatic life. Another challenge was flood control. The existing 22-ft high concrete floodwall combined with daily tidal fluctuations created an inaccessible, muddy, and littered shoreline, so an alternative flood control design was necessary. A third challenge was the shape of the linear waterfront site. Because it is extremely narrow at many points, creating a complete wetland to foster cleaning of the water would be difficult. The narrow points also made access and pedestrian circulation challenging. The park design would need to accommodate the hundreds of thousands of visitors expected during the 6-month Expo, while creating a pleasant and accessible human-scale public park for the long-term.
Using the design concept of a living organism that has the ability to adapt, change, and protect itself, Houtan Park was built as a regenerative living system with a constructed wetland, cascades, and terraces that oxygenate the river water and remove pollutants, nutrients, and sediment. The wetland also acts as a flood protection buffer between 20-year and 1,000-year flood control levees. The existing concrete floodwall was replaced with riprap, which protects the shoreline from erosion while allowing for habitat creation along the water’s edge. A layered approach was used to organize the space, with paths that circulate pedestrians around the site, through the wetlands, and out to the river where a series of docks provide access to the park via ferry water routes. Houtan Park’s aesthetic qualities and ecological functions ensure its continued success long after the Expo.
- Using natural systems to clean polluted river water has a value of approximately $145,000/year when compared with the typical cost of treating water at a water treatment plant in China.
- Reusing steel and bricks found on the site to create the hanging gardens, steel arbors and shade structures, paved areas, and architectural details, saved an estimated $17,300 in material costs.
- Trying new technologies involves risk and a willingness to test and troubleshoot, but can establish a firm as a leader with sought-after expertise. Houtan Park was Turenscape’s first project that used solely ecological process to treat polluted water. The park’s success has led to 8 patents and 20-30 new projects where the firm is applying similar techniques.
Landscape Architect: Turenscape
Urban Planner: Turenscape
Hydrological Engineering: Turenscape
Lighting Engineers: Turenscape
Contractor: Shanghai Landscape Construction Company
Wetland Plant Scientists: Shanghai University of Oceanography
Role of the Landscape Architect
Landscape Architects served as the lead designers and prime consultants for the park. They consulted and coordinated with several other professions including, architects, urban planners, hydrological engineers, lighting engineers, and researchers.
Case Study Prepared By
Research Fellow: Nancy Rottle, Associate Professor, University of Washington
Research Assistant: Delia Lacson, MLA Candidate, University of Washington
Student Researchers: Peter Cromwell, Ying-Ju Yeh, and Chen Hai, MLA Candidates, University of Washington; Xu Tao and Xiaobing Wang in Beijing