Runoff is water, typically from rain, snowmelt, or irrigation, that flows over the land surface and does not infiltrate the soil. Instead, it moves downhill, eventually reaching streams, rivers, lakes, or storm drains. Runoff can pick up pollutants like fertilizers, pesticides, and sediments as it moves, contributing to water pollution. Managing runoff through proper drainage systems, erosion control, and stormwater management practices is essential in both urban and rural areas to reduce flooding and protect water quality.
