Cause and Dangers of Stormwater Runoff


Land development projects typically replace existing natural ground features with new impervious surfaces such as driveways, rooftops, sidewalks and streets. Stormwater runoff occurs when water from snow melt and rain can no longer infiltrate into the ground. The runoff can carry toxic materials into our stormwater drainage systems including:

  • Bacteria
  • Debris
  • Fertilizers
  • Nutrients (such as phosphorous and nitrogen)
  • Oil
  • Pesticides
  • Pet waste
  • Soil particles
  • Trash

Wetlands, streams, lakes, and rivers ultimately receive the discharging waters from all city stormwater systems.


Polluted runoff contributes to:

  • Decline in recreational uses of lakes.
  • Fish kills.
  • Habitat destruction.
  • Reduction in drinking water quality.
  • Stream siltation.