How does urban development typically influence water quality?

Urban development often leads to increased contamination from runoff. This occurs because, as cities expand, there is a significant increase in impervious surfaces such as roads, buildings, and parking lots. These surfaces prevent water from naturally infiltrating into the ground, resulting in more surface runoff during rain events. When it rains, this runoff collects various pollutants—such as oils, heavy metals, debris, and nutrients—from urban areas and transports them directly into nearby waterways. Consequently, the water quality deteriorates, leading to problems such as algal blooms, decreased oxygen levels in water bodies, and harm to aquatic life. This relationship highlights how urbanization can negatively impact water quality through enhanced runoff and pollution.