When it rains, snows or sleets, where does that water go? Does it soak into the ground? Does it sit in puddles until it evaporates? The water actually does both of those things, but some of the water will also flow over the land surface, heading downhill to the nearest ditch or stream. This is called stormwater runoff. In urban areas where there are higher concentratoins of impervious surfaces such as driveways, rooftops, sidewalks, and parking lots, water flows at higher speeds and larger quantities. Storm drains, those openings along roads and in parking lots, help drian the water from homes and streets to keep us safe. These pipes or ditches carry stormwater directly to local creeks and streams without being treated.