Permeable pavement is a stormwater management technology beneficial for long term soil and water preservation. It has significant water quality impact for downstream receiving waters such as lakes, rivers, and ponds. Permeable pavement allows water to infiltrate quickly through the porous pavement and underlying media. As it infiltrates this water is filtered before passing into the ground underneath or to an underdrain.
When designing a system, it is recommended to determine if permeable pavement would be feasible. This design consideration allows a site to benefit by changing the pervious to impervious surface ratios on a location. Permeable pavement can be used in conjunction with other stormwater measures to ensure maximum benefit. Examples include
Different types of permeable pavement include
Permeable pavement can also be used to increase the safety of a site as it has been shown to increase traction and prevent ice accumulation on roadways during adverse weather. (USGS)
For more information on how permeable pavements work please click here.
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.
Water quality: Pollutants are removed through stormwater runoff reduction when permeable pavement is used. This allows for vegetation and biota growth, vegetative filtering, and soil adsorption when rainfall events occur at the site.
Water quantity and hydrology: Reduction in total water volume movement and retardation of peak flow from rainfall events. Helps protect from downstream flooding and can be used in conjunction with reuse systems to reduce required water consumption for onsite irrigation. Infiltration also will recharge local groundwater.
Energy: Main energy savings comes from reduced energy requirements for wastewater treatment.
Air quality: Benefits are largely indirect, such as carbon sequestration.
Climate resiliency: Alleviates the impact on flooding, saves water through reuse systems, reduction of downstream pollutant loading
Habitat improvement: Reduction of soil erosion and increased soil stability promotes vegetation growth. Reduction in water temperature changes as a result of volume flow reduction. Retention of water on site helps ensure available water for vegetation and wildlife.
Community livability: Well designed permeable pavement practices helps to protect recreation sites for people by ensuring safe and healthy access to water sources. Water quality benefits from permeable pavement promote healthy water sources for diverse vegetation growth. This diversity allows for more heterogeneous plant growth and if the water quality is good enough, gardening practices of the local community may not be impacted. Reduction in water on surface ways helps improve safety for driving and human use.
Health benefits: Reduction of nutrients, pathogens, metals, TSS, and phosphorus among others. Increased longevity for fish and wildlife in the area through the reduction of compounds that would be washed into waterways as rain runoff.
Economic benefits and savings: In addition to water quality and flood control benefits, properly installed permeable pavers can prevent downstream cleanup needs. Permeable pavement that benefits vegetation can increase property aesthetics that increase property value.
Maximizing specific green infrastructure (GI) benefits of constructed areas requires design considerations prior to installation. While site limitations cannot always be overcome, the following recommendations are given to maximize the GI benefit.
Note: Permeable pavement SHOULD NOT be used in areas of high traffic volume, with heavy equipment, or with frequent start and stopping.
Information regarding types of permeable pavement can be found here.
Additional general information on permeable pavement can be found here.
Additional considerations for permeable pavement can be found here.
NOTE: It is highly recommended that permeable pavement should NOT be used in areas of high traffic volume, high speed traffic, areas frequented by heavy equipment, or with frequent start and stopping.