Impervious surfaces are hard surfaces that do not occur naturally. They change the behavior of water that enters your property as a result of rain or snow melt by:

• Preventing or retarding its entry into the soil matrix (the solid part of soil)
• Causing it to run off the surface
  • In greater quantities, or
  • At an increased rate of flow 

Examples of impervious surface areas

• Brick pavers
• Building footprints
• Concrete air conditioner pads
• Driveways
• Detached garages
• Parking lots
• Patios
• Sidewalks
• Sheds