Professional Practice

Using Low-Impact Materials: Permeable Surfaces

The site's impervious surfaces where reduced by almost 70% with gravel paths and drought-tolerant planting. ASLA 2014 Professional Residential Design Honor Award. Vineyard retreat, Napa Valley, California / Scott Lewis Landscape Architecture.

Rainfall picks up contaminants from impervious surfaces such as asphalt and concrete streets, driveways, and other pathways, which further contribute to water pollution. In comparison, increasing a site’s permeable surfaces allows for natural filtration and reduces the costs associated with adding stormwater management systems.

Permeable surfaces increase evapotranspiration, filtration and infiltration, and mitigate elevated water temperatures caused by contact with impervious surfaces. Permeable surfaces mitigate and control stormwater runoff by allowing water to pass through into the underlying soils. This kind of natural filtration process is the most effective way of eliminating water contaminants and pollutants.

Soil on residential properties can be degraded and compacted after years of development. Often times, thin layers of turf are rolled out over degraded soil, leaving the grass roots with no soil to grown into. The lawn will need a lot of fertilizer and water to survive, and the thin veneer of grass does not help capture any stormwater. Homeowners can use soil remediation techniques like subsoiling and adding soil amendments to improve water absorption, promote plant root establishment, and increase surface permeability.

Landscape architects can design residential properties to increase a site’s permeability with additional vegetation and soils and limit hardscapes by using porous materials like gravel and mulch.

More Resources
 
Permeable Pavers

Organizations 

The Sustainable SITES Initiative™ (SITES®) 

Depave Project 

Resources 

Reduce Impervious Surfaces, RecycleWorks, County of San Mateo

Richmond’s Green Alleys, The DIRT, American Society of Landscape Architects

What Makes a Green Street, The DIRT, American Society of Landscape Architects

“Handbook of Biophilic City Planning and Design,” Timothy Beatley, Island Press, 2016

Permeable Materials, Paths for All, Scottish Government

Designing with Soils, The Dirt, American Society of Landscape Architects

Using Health Soils to Manage Stormwater, The Dirt, American Society of Landscape Architects

Government Resources 

Permeable Alleys, City of Chicago

Green Alley Handbook, City of Chicago

Permeable Surfaces, Florida Field Guide to Low Impact Development, University of Florida

Permeable Pavers and Re-Vegetation, Department of Energy & Environment, D.C.

The Avalon Green Alley Network Demonstration Project, Los Angeles Trust for Public Land

Projects 

Vineyard Retreat, Napa Valley, California
Scott Lewis Landscape Architecture

Cambridge Permeable Driveway, Cambridge, Massachusetts
Julie Moir Messervy Design Studio

The Crack Garden, San Francisco, California
CMG Landscape Architecture 

Alleé de Berlin Spandau, Paris, France
Espace Libre

Permeable Pavers 

The Sustainable SITES Initiative™  (SITES®) strongly encourages permeable over impervious surfaces. Where hardscapes are needed permeable pavers, or pavement with high porosity, can be used to help reduce stormwater runoff and water infiltration into the ground. Permeable pavers can also trap pollutants that would otherwise enter local water sheds. Permeable paving can allow up to 80 percent of annual rainfall to infiltrate the underlying soil. Residential driveways and walkways can incorporate permeable materials while still maintaining a high-level of aesthetic quality. Often, these materials are also more reflective, which can help decrease the heat island effect.

Source: Permeable pavement, Green Building Alliance; Fact Sheet: Permeable Paving, Metropolitan Area Planning Council 

Organizations 

Pavement Interactive 

Interlocking Concrete Pavement Institute 

Pervious Pavement 

Resources 

Sustainable Paving in Use, Interpave

Permeable Paving, Green Building Alliance

Permeable Paving, Landscaping Network

Research 

“Permeable Pavements,” Permeable Pavements Task Committee, LEED AP Bethany Eisenberg, P.E. Kelly Collins Lindow, David R. Smith, American Society of Civil Engineers, 2015

"Porous Pavements (Integrative Studies in Water Management and Land Development)," Bruce K. Ferguson. CRC, 2005

Government Resources 

Design criteria for permeable pavement, Minnesota Stormwater Manual

De-paving and Permeable Pavers, City of Philadelphia

Soak Up the Rain, Permeable Pavement, Environmental Protection Agency

Pervious Pavement, Environmental Services, City of Portland

Projects 

Drs. Julian and Raye Richardson Apartments, San Francisco
Andrea Cochran Landscape Architecture