Through the center of Turenscape’s Shanghai Houtan Park runs a linear –1.7 kM long, 5-30 meters wide — constructed wetland designed to treat contaminated water from the Huangpu River. Cascades and terraces were employed to remove contaminants, retain nutrients, reduce suspended sediments, and oxygenate the water. Different wetland plant species where selected and arranged in sequence to foment the cleaning process and systematic extraction of the pollutants that afflict the Huangpu.
In addition, the wetland also acts as a flood protection buffer between the 20- and 1000-year flood control levees. 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. (Turenscape, 2010)
The terrace design of the wetland alleviates the elevation difference between the city and the river, safely reconnecting people to the water’s edge. Additionally, the existing concrete floodwall was replaced by a more habitat-friendly riprap that allows native species to grow along the riverbank while protecting the shoreline from erosion. (Turenscape, 2010)
Turenscape supported the effectiveness of the wetland cascade cleaning system through field tests. The tests showed that over 2,400 cubic meters (500,000 gallons) per day of water can be treated from Lower Grade V to Grade III. The benefits are that the treated water can be then used safely for non-potable uses and in the long run save a lot of money in comparison to conventional water treatment.
This project has won numerous awards, including the ‘World’s Best Landscape’ award at the World Architecture Festival Awards (WAF Awards) 2010 and an Award of Excellence in the 2010 ASLA Professional Awards.
Text Excerpt Credits: (Turenscape, 2010)