Understanding Stormwater Terms
Impervious Surfaces
These are surfaces that don’t allow water to soak into the ground. Examples include rooftops, buildings, streets, parking lots, driveways, sidewalks, patios, concrete, asphalt, and even artificial turf. Because they block natural water absorption, impervious surfaces increase the amount and speed of stormwater runoff, which can lead to flooding and pollution.
Storm Drains
Storm drains are openings—usually along curbs or in parking lots—that collect rainwater runoff from paved areas and direct it into the city’s drainage system. They help reduce surface flooding and guide water away from roads and properties.
Catch Basins
Catch basins are underground structures located beneath storm drains. They "catch" or collect debris, sediment, oils, and pollutants from stormwater before it flows into the stormwater system and eventually our canals and waterways. Items like motor oil, paint, pesticides, cigarette butts, pet waste, trash, and even golf balls can accumulate in catch basins. Routine cleaning and maintenance are essential to keep these pollutants out of our environment and ensure our stormwater system works effectively.