Design and performance of a water quality treatment wetland in a public park in Shanghai, China

A water quality treatment (WQT) wetland system was installed in a public park in Shanghai to achieve a number of complementary objectives: (1) to serve as a demonstration of ecological engineering practices for the improvement of water quality in a degraded urban river (Suzhou Creek), (2) to demonstrate that such systems can provide new, viable aquatic habitat in these settings, and (3) to provide a recreational, aesthetic and educational amenity for the neighbourhood residents. After 2 years of operation, the system was found to have successfully achieved the water quality improvement objectives (in terms of improvements in parameters like solids, organics and nutrients). The aquatic habitat was found to be diverse, abundant and evolving, and ecological risk to this habitat and Suzhou Creek was reduced through the treatment system (as indicated by the results of bioassay toxicity testing). Property values in the neighborhood had increased as an indirect result of the presence of this natural treatment system, and there was broad public acceptance of the system, as well as broad interest in its educational aspects, as part of a natural and sustainable approach to the restoration of degraded aquatic environments.