How can plastic waste clog drainage systems and contribute to flooding?

Plastic waste contributes to flooding by physically obstructing drainage infrastructure. Items such as plastic bags, films, and other discarded packaging accumulate within drainage systems, creating blockages that prevent the normal flow of water. When these systems are clogged, they cannot effectively manage stormwater runoff, which leads to the flooding of low-lying areas.12

This issue is exacerbated by the nature of synthetic plastic, which is largely nonbiodegradable and persists in the environment. Because much of this waste is improperly disposed of—often ending up as litter in urban areas—it is easily transported by wind or stormwater runoff into drainage networks. Consequently, the accumulation of these materials creates significant challenges for urban water management and public safety.312