Advancing the Sponge City Agenda: evaluation of 22 plant species across a broad range of life forms for stormwater management

Harsha Fowdar, Emily Payne, Ana Deletic, Kefeng Zhang, David McCarthy

Research output: Contribution to journalArticleResearchpeer-review

4 Citations (Scopus)

Abstract

In 2012, China introduced the Sponge City Agenda as a solution to challenges such as increasing urbanisation and population growth, leading to urban flooding and water pollution. The initiative requires new nature-based technologies tailored for Chinese conditions. Biofiltration or bioretention systems have proven to be promising technologies to mitigate stormwater pollution. Plant selection form a key component of system design. However, to date plant selection research has been limited, largely focusing on Australian native species monitored under a limited number of wetting and drying patterns. To address this gap, a large scale laboratory study was undertaken to test the hydraulic and treatment performance of 22 plant species, native to or common to Jiangsu Province, China, over a period of 15 months under varying frequency of inflows (corresponding to 3, 15 and 22 antecedent dry days). A wide variation in system infiltration capacity (up to 8-fold), nitrogen removal (up to 5-fold during wet conditions and up to 10-fold during dry conditions, between 20% and 80%) and phosphorus removal (up to 2-fold, between 35% and 95%) was found across plant species. In regards to heavy metals, plant-related contributions were observed for Cd, Ni and Zn removal (up to 90% removal overall). Overall, this study shows that while plants are not universally effective, a range of plant species, across a broad range of life forms, encompassing flowering herbs, reeds, shrubs, grasses, sedges, climbing plants and trees, can be used for effective stormwater treatment in China and elsewhere. It points to plant morphological and physiological characteristics being more important parameters and suggest future work investigate the relationship between plant evapotranspiration, water dynamics (incl. Antecedent drying), root traits and pollutant removal to advance the sustainable use of plants for stormwater treatment.

Original languageEnglish
Article number106501
Number of pages11
JournalEcological Engineering
Volume175
DOIs
Publication statusPublished - Feb 2022

Keywords

  • Biofiltration
  • Green façades
  • Phytoremediation
  • Rain gardens
  • Urban green infrastructure
  • Water quality

Cite this