Parking designers and planners are joining the ever-growing legion of individuals concerned with climate change, and its effects on natural habitats and species. Looking to make their own “green” gestures, designers and planners are implementing sustainable, environmental-friendly elements and features into parking structures and surface parking lots.

Designers and planners are discovering that “green” design elements are not only good for ensuring a parking surface lot or parking structure’s sustainability efforts, but good for the bottom line, saving tens of thousands of dollars each year. When applied properly, “green” parking design elements can also help protect area water supplies and visually enhance a site.

Detailed below are some of the more popular “green” design elements being applied in parking structures and surface parking lots across the country.

Porous Pavement and Stone Reservoirs

Most surface parking lots are made of pavement, an impervious material that collects stormwater on its surface and does not allow it to filter into the soil. Surface parking lots have traditionally been built with pipes, curbing, gutters and drains to channel stormwater. However, the stormwater is often contaminated with many types of petroleum residues, fertilizers, pesticides and other pollutants from parking surfaces. The water also enters a municipality’s sewer system at an unnaturally high rate and volume. According to the United States Geological Survey, an impervious, man-made surface will generate two to six times more runoff than a natural surface.

A system that includes porous pavement and stone reservoirs is one way to fix this problem. Under such a system, rainwater passes through the porous pavement and collects in a reservoir located underneath the surface. The rainwater is treated for the containments that frequently accumulate in parking lots before being directed toward a municipality’s sewer system. The temperature of the water is reduced; the rainwater is also released at decreased volumes and at a much slower rate than in a typical drainage infrastructure system, guaranteeing the municipality’s sewer system is not overwhelmed.

‘Green’ Landscape Elements

There are also a number of landscape elements that can “green” up a surface parking lot. For example, rain gardens collect rainwater runoff, and help lower nitrogen and phosphorus levels. They typically consist of a grass buffer strip, a shallow ponding area, an organic layer, planting soil and vegetation. Rain gardens are typically used in parking lot islands and are ideal for surface parking lots in dense urban areas with few open spaces.

Bio-swales, which are vegetated storm water collection areas that slope to a destination, are another way to reduce the negative impacts of surface lots. Bio-swales are open channels or depressions with dense vegetation used to transport, decelerate and treat runoff. At surface parking lots, they are designed to help direct water into bioretention areas. Unlike rain gardens, they require a large amount of surface space and are better suited for more rural areas.