Houtan Park — Constructed Wetland Water Treatment on a Reclaimed Shanghai Brownfield

Houtan Park occupies a 14-hectare brownfield on the south bank of the Huangpu River in Pudong, Shanghai — formerly a steel factory and shipyard — redesigned by Turenscape (led by Kongjian Yu) for the 2010 Shanghai World Expo and kept afterward as a public riverfront park.

Its centerpiece is a roughly 1-mile-long (1.7 km), 5-30 metre-wide constructed wetland: river water is diverted through a series of cascading, terraced wetland cells planted with species selected for pollutant uptake, using settling, aeration and microbial processes to purify it entirely without chemical treatment. The park also replaced a 22-foot concrete floodwall with a graded riprap edge that functions as a buffer between 20-year and 1,000-year flood-control levees.

The Landscape Performance Series case study reports the wetland treats roughly 2,400 tonnes (about 634,000 gallons) of water per day, raising it from Grade V (unfit for human contact) to Grade II/III (suitable for irrigation and non-potable reuse); 93 plant species and over 200 animal species have been documented on site, and the same source estimates roughly 242 tonnes of CO2 sequestered annually and about $116,800/year in water-cost savings for an adjacent facility. The design won ASLA's 2010 Award of Excellence and, per Turenscape, produced 8 patents and informed 20-30 later projects.

The detailed treatment-capacity, carbon and cost figures trace to a single design-firm-submitted case study (assessed under the Landscape Performance Series' own methodology) rather than an independent government water-quality audit, so they should be read as credible but not independently re-verified.