Drains in the gutter, designed to shuttle away storm water in urban or suburban areas. Developed areas that feature homes, offices, and retail stores cover up the ground with buildings, and pave surrounding areas with non-permeable surfaces, like sidewalks, driveways, and roads). Thus, rain, instead of being absorbed by the ground, is channeled away from houses, usually into the streets. To prevent flooding of streets, drains are added to gutters.

Most storm drains do not drain to the local sewer system-- whatever enters the drain is discharged directly into local waterways (creeks, streams, flood channels, rivers). This is why urban runoff, suburban runoff, and non-point source pollution are often the biggest cause of water pollution, and why local environmental groups may champion storm drain stencilling projects to raise awareness and protect watersheds.

It's also why it's not a good idea to dump leftover paint, cleaner, antifreeze, used oil, soap, pet waste or yard waste into the gutter.


Grates on storm drains parallel to the direction of the roadway can be a hazard for bicyclists, as the openings in them can catch tires.
During times of high flooding, the force of water entering drains may be strong enough trap a person, making for dramatic television (either on the news, or staged for dramatic effect on "reality" shows or dramas).