Summary

The Clean Water Act of 1972 was the impetus for stormwater management in the United States, followed by the need for many cities to comply with consent decrees associated with combined sewer overflows. With rapidly growing urban centers and the attendant increasing costs of managing stormwater with larger stormwater facilities, green stormwater infrastructure (GSI) was deemed a useful measure to distribute the management of stormwater across the landscape. The management of stormwater has evolved from simply removing it as quickly as it is generated in order to prevent flooding, to intentionally detaining stormwater on the landscape. Typically, low-frequency large events are detained in central stormwater holding facilities, while GSI is employed to manage smaller high-frequency events, slowing and treating stormwater on the landscape itself. Installing GSI close to the source of runoff production ensures that stormwater directed towards these facilities are small enough in volume, so as not to overwhelm these systems. Within these GSI systems, the natural assimilative capacity of soils and plants slows and breaks down many of the pollutants that are found in stormwater runoff.

The requirement for a broad spatial distribution of GSI across the landscape necessitates an acceptance of these technologies, and the willingness of the managers of these urban landscapes to maintain these systems on a continual basis. The policies put in place to transfer the responsibility of stormwater management onto individual lot owners range from regulations imposed on those that develop the landscape for commercial and industrial purposes, to incentives offered to individual lot owners to install GSI practices for the first time on their properties. GSI is, however, not a silver bullet for all stormwater ills, and care has to be taken in how it is deployed in order not to exacerbate systemic environmental and racial inequities. A careful and considered adoption of GSI that includes the desires, values, and the needs of the community in conjunction with the environmental goals they are designed to address is critical.