G R E E N I N F R A S T R U C T U R E A N D S U S TA I N A B L E D E S I G N
in the twentieth century, sustainability and creating healthy, livable communities gained support. The idea of design with nature1 was understood as a workable means to making better decisions. Natural systems can be incorporated into effective and sustainable strategies to significantly protect communities from flooding, moderate unwanted heat gain, and help to improve air and water quality. When nature is harnessed and incorporated into the design of infrastructural systems, it is called “green infrastructure.”2 Green infrastructure can be applied at all scales of the built environment and is closely associated with storm-water management, although it is being applied to a growing range of applications toward improving biodiversity, creating natural barriers or recovery systems from natural disasters, and improving the quality of life for urban dwellers. Through the process of design, landscape architects incorporate site design and development practices that will allow healthy, naturally functioning ecosystems to continue. Incorporating the idea of design that maintains the healthy functioning of the ecosystems applies whether the project site is a large neighborhood, a commercial center, a park or sports facility, or an individual residence. By considering the implementation of sustainable design strategies. development on the land can avoid, mitigate, and possibly reverse detrimental environmental impacts and at the same time advance the quality of life and enhance economic values. By example, the environmental impact—specifically of hydrologic systems—of the construction of new roadways in the city of Houston, Texas, and other cities in North America has been substantially reduced by applying low impact design measures in the design of the roads. Implementing low impact development (LID) has been shown to reduce the total cost of construction substantially versus the cost of constructing traditional roadway designs. Long-term maintenance costs of the roadways designed with low impact development guidelines have been substantially reduced by 25–40 percent. This is a conservative range of savings as compared to the range reported by the Environment Protection Agency. Less easily quantifiable is the added value realized in terms of aesthetics with increased landscaping. An increase in property values of the adjoining neighborhoods is also a result of LID design guidelines.
Plants in Combination with Grading and the Environment While plants have been a constant presence in human history, new ways of appreciating their impact on our lives are revealed as their extent and diversity are diminished with our desire for progress and capacity for consumption. Natural and planted trees and associated plant cover help regulate local climate and reduce the energy costs of buildings by providing shade and reducing the action of wind. Through evaporation, transpiration, and the uptake and storage of carbon, plants moderate the climate and improve air and water quality. Natural plant communities, such as wetlands, reduce the impact of storms and function as valuable animal habitat. Similarly, planting of vegetation in urban areas serves as animal habitat, reduces heat 193
