Stormwater and the pollution it spreads is becoming a major issue, especially in cities where it is the most difficult to control runoff. The greater amount of impermeable surface in cities prevents rainwater and snowmelt from penetrating the surface. Instead, the rainwater and snowmelt becomes runoff along our streets. Managing stormwater, and the pollution it carries, is a crucial part of protecting both residents and the infrastructure of a city. Green infrastructure is one way that cities can achieve this goal.