Introduction to Urban Stormwater and Green Stormwater Infrastructure

Abstract

The governing legislation driving urban stormwater management in the United States is the Clean Water Act (CWA). Initially enforcement of the CWA focused on discharges of wastewater (sometimes untreated) from municipal wastewater treatment plants and from various industries. Green stormwater infrastructure (GSI) can be more flexible and resilient than traditional curb, gutter, and piping systems (“gray infrastructure”), as there may be some dampening of the effect due its functional dependence on natural processes. The ideals of GSI are to mitigate the deleterious effects of urban stormwater using natural processes such as vegetation and soils at or near where the rain falls. A number of techniques and processes are employed to reduce the impacts of urban stormwater runoff. Collectively, these are known as stormwater control measures (SCMs). Common green infrastructure SCMs include vegetated technologies such as vegetated swales and filter strips, rain gardens and bioretention, green roofs, and wetlands.