By Thomas R. Tavella, FASLA
Sometimes sustainability occurs without fanfare. Some industries are so “green” that people within them take advances in sustainability for granted. Landscape architecture is one such industry.
When Frederick Law Olmsted created the field of landscape architecture in the late 1800s, the Green Revolution was a century away. Olmsted wasn’t interested in being trendy or promoting a new philosophy regarding how Americans should think and behave. Rather, he was merely promoting the creation of healthier cities—and more livable neighborhoods within those cities. Olmsted and his contemporaries understood that the more people are outside, working and playing in natural environments, the healthier they will be.
In Olmsted’s time, America was growing up fast. The nation’s cities were experiencing an explosion of development that threatened residents’ quality of life. Neighborhoods were choked with smog, disease was rampant, and many urban residents lived day after day secluded from nature. Social scientists recognized that these were unhealthy living conditions and began to promote the creation of urban parks to promote more livable cities. A prominent proponent of greener cities, Olmsted went on to create some of America’s iconic parks, including New York’s Central Park and the Emerald Necklace in Boston. In 1899, he was instrumental in the creation of the American Society of Landscape Architects.
In a sense, this was the true beginning of the Green Revolution in America. It took more than a century to take hold,but the values and advances encouraged by those early landscape architects continue to promote sustainability and improve the quality of life in today’s communities.
More than just aesthetic benefits
People often think of landscape architecture as a way to decorate or “green up” properties or urban areas. However, landscape architecture provides essential infrastructure that does much more. Designed landscapes can prevent soil erosion around buildings and other developed areas, clean storm water runoff by filtering contaminants, encourage groundwater recharge, and offer valuable shade to protect buildings and people.
Landscape architects are promoting sustainability through the creation of biofiltration swales in urban areas. Rainwater can collect pollutants before entering storm drains, and eventually local streams and wetlands. Biofiltration swales are comprised of grasses and durable plants that can withstand the most extreme conditions, including extensive rain and severe heat. They receive stormwater runoff and slow it down, which helps reduce erosion and flooding. The swales will clean the runoff by naturally filtering out contaminants before it is then safely distributed to sewers for disposal. Some plants are able to filter heavy metals from water, which is particularly useful in industrial areas.
Pervious pavements are another popular design element in today’s cities. Various types of pervious pavements and pavers exist, all of which contain voids through which runoff can permeate into the soil. The pavement serves as a filtration system for oils and other contaminants while also allowing for groundwater recharge and reduced overland runoff. This contaminant filtration can be especially beneficial when used in roadways and other areas where vehicles typically leak contaminants. Engineers and planners are sometimes hesitant to use pervious pavements in cold weather areas, fearing that they could freeze over in icy weather. However, experience has shown that they are actually particularly useful in Northern areas because their design keeps the ground warmer than traditionally paved roadways.
Another approach that is becoming increasingly popular is the inclusion of green roofs on new developments—from residential complexes to business centers and commercial developments. Even parking garages are starting to sport green roofs! Green roofs (also known as “living” roofs) are composed of trees and shrubs or low-growth grasses and sedums. In addition to offering an attractive flourish to a building, green roofs reduce building heating and cooling costs, provide wildlife habitat, and reduce urban air temperature, which lessens urban heat island effect. Green roofs can also help absorb and filter storm water, and reduce the temperature of water that is discharged into sewer systems, lakes, and streams.
Finally, the introduction of street trees and shrubs into urban settings can have a dramatic impact on promoting sustainability. The air quality benefits of plants are well known. Plants consume carbon dioxide and return oxygen to the atmosphere, which improves overall air quality. By cooling the air, plants also make the local environment healthier during excessively hot weather. Air temperatures can be up to 20 degrees cooler beneath trees. Overall, trees and other types of vegetation can have a dramatic positive impact by reducing urban heat island effect.
More sustainable, livable, and healthier cities
These are just a few examples of the many ways that landscape architects are producinggreener communities. We are very fortunate to be living in an age of constant technological advancement and many of the most important breakthroughs are in sustainable technologies—or in these cases, tried and true practices with a new twist. In the coming years, we can count on seeing many more advances that will allow us to use plants and landscape technologies to create even more sustainable, livable, and healthier cities.
Thomas R. Tavella, FASLA, is director of design for Fuss & O’Neill’s Landscape Architecture Studio and president-elect of the American Society of Landscape Architects. Manchester, Conn.-based Fuss & O’Neill is ranked among the top 200 environmental firms and top 500 design firms in the United States. Tavella can be reached at TTavella@fando.com.