In descending order, by date published.
Urban areas are characterized by impervious surfaces such as roads, driveways, sidewalks, and building roofs. Stormwater occurs when precipitation runs off these impervious surfaces. Stormwater can present both water quality and water quantity issues in urban watersheds. Water quality of local waterways is threatened when stormwater carries pollutants to streams and rivers; increased water quantity in these local waterways can damage streambanks, cause flooding, and create more water quality problems.
Managing runoff in urban areas offers many challenges for engineers, landscape architects, and planners. As cities grow, the amount of impermeable surfaces--those that do not allow water to infiltrate into the ground--increases. Examples of impervious surfaces are asphalt roads, concrete sidewalks, parking lots, building roofs, and areas of highly compacted soils such as in subdivisions. If not properly managed, the stormwater runoff produced by these impermeable surfaces can have negative effects on nearby surface waters.
Stormwater is excess water from rainfall and snowmelts that flows over the ground and does not infiltrate the soil. It is a concern not just in urban areas but in suburban and agricultural locations as well. As stormwater runoff flows over the land or impervious surfaces, it picks up and transports trash and debris as well as pollutants such as pathogens, nutrients, sediments, heavy metals, and chemicals. This publication reviews some of these techniques and provides a list of recommended resources for additional information.