What are the consequences of urban runoff on water bodies?

Urban runoff significantly impacts water bodies primarily by transporting various pollutants from urban areas into streams, rivers, lakes, and oceans. As rainfall washes over impervious surfaces like roads and parking lots, it collects contaminants such as oil, heavy metals, nutrients (like nitrogen and phosphorus), and trash. This polluted water flows directly into aquatic ecosystems without any natural filtration, leading to degradation of water quality.

This degradation manifests in several ways. First, the excess nutrients from runoff can cause algal blooms, which deplete oxygen levels as they decay, creating hypoxic (low oxygen) conditions detrimental to aquatic life. Additionally, heavy metals and other toxic substances can accumulate in the sediment or be ingested by aquatic organisms, potentially leading to bioaccumulation and impacting the food chain.

Ultimately, the introduction of these pollutants disrupts the natural balance of aquatic ecosystems, leading to compromised water quality, loss of biodiversity, and harm to the organisms that rely on clean water for survival. Therefore, understanding the role of urban runoff in transporting pollutants is crucial for addressing water quality issues in affected water bodies.