Stormwater runoff is rain or melting snow that collects on the surface or flows into sewer pipes instead of seeping into the ground.
Runoff will either:
- Soak into the ground
- Get absorbed by plants
- Flow along the surface to the nearest sewer or waterway
In urban areas, we have a greater amount of runoff since we have decreased our natural ability to soak up water. When fields and forests are replaced with roads, parking lots and buildings, less rainfall can soak back into the ground and more water collects on hard surfaces. This increased runoff quickly drains via paved surfaces and storm sewers to local streams and rivers.