Montgomery County Department of Environmental Protection defines pervious pavement as having more air spaces than regular pavement, allowing water to drain through the surface into the underlying soil. Most paved surfaces are currently impervious, but Environmental Site Design (ESD) efforts including installation of pervious pavement are being required for new development as well as redevelopment of properties in Montgomery County.

Applying ESD techniques such as pervious pavement in place of asphalt will help to reduce runoff and issues with flooding, as well as improve water quality. Replacing asphalt surfaces with pervious pavement can provide other ecological, social, and economic benefits.  Pervious pavement functions to slow water and allow infiltration while filtering stormwater on-site. Adding trees and vegetation in previously paved areas can provide comfortable spaces by reducing urban heat island effects and improving air quality as well as overall human health. Pervious pavements and vegetated areas help to reduce energy costs and add aesthetic appeal to any environment (

Petro has worked on several projects utilizing ESD techniques, including pervious pavement. Petro used pervious concrete and vegetation to help alleviate issues with pooling and flooding at a residence in Columbia, Maryland. The photo below shows the pervious concrete next to older standard concrete.

Pervious Concrete

Pervious and Cobblestone