A myriad of problems can result from impervious surfaces: urban heat islands (asphalt-laden cities that are several degrees hotter than surrounding areas), altered stream flows (lower lows and higher highs, increased flooding), and polluted waters (from unfiltered road- and parking-surface runoff). Fortunately, cities are starting to see the economic and social value of preserving and restoring natural capital. Shade trees can reduce ambient air temperature by 15 degrees. Natural drainage can be far less expensive up-front, and far less costly in avoided flooding, pollution, and stream damage in the long run. There are many options for reducing stormwater runoff from a site, including reinforced grass paving, porous asphalt, rainwater-collection cisterns, infiltration islands in parking lots, swales, dry wells, and planted stormwater retention areas.

One type of landscape often overlooked in development is edible plantings. Gardens, orchards, or crops can and should be incorporated into both residential and commercial projects. These plantings can serve all the functions of non-edible landscaping (e.g., cooling and stormwater absorption) and produce food as well. The Village Homes community in Davis, CA, for instance, has a revenue-producing almond orchard, as well as a wide variety of fruit trees interspersed along pedestrian paths.

Although turf grass serves to facilitate many functions, such as play and picnic areas, it need not be planted ubiquitously in areas that are not going to be used for those functions. The turf grass that is planted on lawns and corporate campuses is typically a non-native, monoculture crop that requires constant human input (mowing, watering, fertilizing, and dousing with pesticides and herbicides). These inputs are neither cheap nor environmentally sound. By contrast, native landscape is perfectly adapted to thrive in the local environment and therefore needs no irrigation or fertilizer, is ecologically diverse enough to resist pests, and provides free stormwater management. When landscape architect Jim Patchett replaced turf grass with native prairie on the Lyle, Illinois, campus of AT&T, multiple problems were solved, while maintenance costs dropped from $2,000 to $500 per acre.

Excerpted from Green Building: Project Planning & Cost Est, 3rd edition, available through RSMeans.