Green infrastructure (GI) encompasses a wide array of practices, including stormwater management. Green stormwater infrastructure (GSI) encompasses a variety of practices primarily designed for managing stormwater runoff but that provide additional benefits such as habitat or aesthetic value. There is no universal definition of GI or GSI (link here for more information). Consequently, the terms are often interchanged, leading to confusion and misinterpretation. GSI practices are designed to function as stormwater practices first (e.g. flood control, treatment of runoff, volume control), but they can provide additional benefits. Though designed for stormwater function, GSI practices, where appropriate, should be designed to deliver multiple benefits (often termed "multiple stacked benefits". For more information on green infrastructure, ecosystem services, and sustainability, link to Multiple benefits of green infrastructure and role of green infrastructure in sustainability and ecosystem services.
Permeable pavement is a beneficial technology for stormwater management. This technology is highly beneficial for long term soil and water preservation of a site and has significant water quality impact for downstream systems such as lakes, rivers, and ponds. This technology operates by allowing water to flush quickly through pavement systems that would otherwise act as a conveyance system and remove water from a site. This water is instead drained directly downward through the pavement and into the ground underneath.
When designing a system, it is recommended to determine if permeable pavement would be feasible. Smaller sites may not see as much benefit due to lower runoff volumes but roadways, parking lots, and any other appropriate paved surface may benefit from this. Permeable pavement can be used in conjunction with other stormwater measures to ensure maximum benefit. Some key examples are:
Permeable pavement built with underground cisterns, vaults, or other treatment devices Permeable pavement used with irrigation stormwater reuse Increased vegetation options at a site due to increased groundwater accessibility Systems in which other infiltration methods are difficult to achieve or may cause detrimental effects
Different types of permeable pavement include:
Interlocking pavers
Pervious concrete
Porous asphalt
Plastic grid pavers
—insert pictures of permeable pavement types--
With this in mind, permeable pavement can also be used to increase the safety of a site as it has been shown to increase traction for roadways during adverse weather and when used in outdoor sporting courts such as tennis and basketball, it can help prevent injuries by reducing the water that pools on the site.
For more information on how permeable pavements work please click here.