Author(s): An Liu; Buddhi Wijesiri; Ashantha Goonetilleke

Linked Author(s): An Liu

Keywords: Global warming; Stormwater management; Urbanization; Alternative water resources

Abstract: Stormwater represents a largely untapped resource that could help mitigate water shortages in urban areas. However, it requires treatment prior to use. Furthermore, projected shifts in rainfall patterns due to global warming are expected to alter stormwater quality characteristics. This study forecasts potential changes in the main source of stormwater degradation —particulates that carry the largest proportion of toxic pollutants, such as heavy metals. Findings reveal that global warming of 1.5 °C and 2 °C could lead to an increase in toxic pollutant loads by over 90% on urban surfaces and by nearly 50% in stormwater runoff. Under the upper-range projections for extended dry periods and intensified precipitation within the Representative Concentration Pathway (RCP) 8.5 scenario, stormwater quality is anticipated to further deteriorate. Compared to current conditions, the results suggest that cities will encounter greater challenges in designing effective measures to manage increasingly complex stormwater quality dynamics influenced by varying dry and wet weather conditions. Consequently, this study highlights that to protect stormwater reuse and reduce ecological risks, adaptive design must explicitly account for particle-specific responses to climate change and strengthen linkages between urban hydrological dynamics and ecohydraulic integrity.

DOI: https://doi.org/10.64697/iahr.proc.ise2026.abs.109

Year: 2026