Authors Seek Comments on Sustainable Landscaping Report

The Sustainable Sites Initiative, a partnership of American Society of Landscape Architects, Lady Bird Johnson Wildflower Center at University of Texas at Austin and United States Botanic Gardens, in November released a draft version of its joint 179-page report, “Sustainable Sites Initiative: Guidelines and Performance Benchmarks.” The groups are accepting comments on the draft report accessible at ASLA’s website through Jan. 20, 2009.

The partnership plans to provide three documents by 2012 to foster its mission of more sustainable land use. This includes an update guidelines and benchmarks report to be published in 2009, a rating system for sites by 2011 and a reference guide by 2012.

The program, founded in 2005, defines sustainability as “design, construction, operations and maintenance practices that meet the needs of the present without compromising the ability of future generations to meet their own needs.” Essentially, the initiative seeks sites that will provide a full array of “ecosystem services” or environmental benefits, including climate regulation, erosion control, air and water cleansing, water supply regulation, hazard mitigation, habitat provision, waste decomposition, health benefits, food and raw material provision and cultural benefits.

“The central message of The Sustainable Sites Initiative is that any landscape — whether the site of a large subdivision, a shopping mall, a park, an abandoned rail yard or even one home — holds the potential both to improve and to regenerate the natural benefits and services provided by ecosystems in their undeveloped state,” reads the report. “However, efforts to preserve and restore healthy ecosystems face a significant challenge — namely, persuading decision-makers that the cost of changing conventional methods of landscape design, development and maintenance is money well spent.”

The report also addresses the cost of unsustainable practices, such as soil compaction during construction, which can lead to polluted and contaminated stormwater runoff, and treating water as waste rather than a resource by funneling rainwater from roof gutters directly to sewers or by irrigating unsustainable landscapes.

The report’s core, of course, is the actual benchmarks used to supplement U.S. Green Building Council’s LEED (Leadership in Energy and Environmental Design) certification programs and other rating systems. The benchmarks include prerequisites (benchmarks that must be met for a site to qualify as sustainable) and credits (optional benchmarks).  

For example, under the category of site selection, sustainable sites must 1) preserve any threatened or endangered species habitat, 2) protect and restore floodplain functions of riparian and coastal zones and 3) limit disturbance of prime farmland soils, unique soils and soils of statewide importance — all three prerequisites. Projects could earn additional credits if they included the redevelopment of brownfields or greyfields.  

The Sustainable Sites Initiative defines sustainability as design, construction, operations and maintenance practices that meet the needs of the present without compromising the ability of future generations to meet their own needs.

Other prerequisites listed in the draft report include: controlling and managing invasive species; using appropriate, noninvasive species; reducing potable water consumption for irrigation; and plan for sustainable landscape maintenance. Other credits listed in the draft report include: minimizing or eliminating potable water consumption for irrigation; promoting a sense of place with native vegetation; preserving and restoring native wildlife habitat; protecting and restoring riparian and wetland buffers; repairing or restoring damaged or lost streams, wetlands and coastal habitats; cleanse water on-site; eliminate potable water use in ornamental or stormwater features; minimize use of potable water in water features designed for full human contact; mitigate potential wildfire risks; provide outdoor spaces for mental restoration; design stormwater management features to be a landscape amenity; reuse on-site structures, hardscape and landscape amenities; recycle organic matter generated during site operations and maintenance; and use renewable sources for site outdoor electricity.

For each requisite and credit, the report offers at least one page of additional information, including intent, requirements, suggested submittal documentation, technologies and strategies and resources for the benchmark. For example, for the “providing outdoor spaces for mental restoration” credit, the report said the area must meet four of five components. Those components include an amenity or view that encourages site users to use the space (including water features), comfortable seating, comfortable settings that respond to the microclimate (such as shade and windbreaks), vegetation cover and mitigation of existing stressful factors, such as noise.

The report also includes various case studies, including one from Santa Monica, Calif., where in 2003 the city installed two adjacent 1,900-square-foot gardens in an effort to promote sustainable garden practices to residents and local professional landscapers. One garden was traditional (exotic plants from Europe and eastern U.S.; standard, user-controlled sprinkler irrigation system; and no provision for runoff mitigation); the other, native (climate-appropriate cultivars; drip irrigation with weather-sensitive controller; and rainwater recovery system and permeable paving).

The traditional garden cost $12,400 to construct compared to $16,700 for the native garden. It used 283,981 gallons of water from 2004 to 2008 (more than 219,000 more gallons than the native garden), produced 647.5 pounds of green waste (428.5 more pounds than the native garden) and cost $223.22 to maintain over that time, compare to $70.44 for the native garden.

Prior to releasing the draft report, ASLA released survey results that showed U.S. adults were relatively unlikely to use sustainable or energy-efficient practices in their yards compared to inside their homes. Although 96 percent of 2,253 U.S. adults reported they had adopted “green” practices inside their homes, only 58 percent had adopted energy- or water-saving techniques in their landscaping, according to the poll conducted by Harris Interactive in late September 2008.

In that study, as reported by the group’s Land Online publication, respondents seemed responsive to sustainable landscape practices, with only 19 percent disagreeing with the statement that green practices saved money, 16 percent disagreeing with the statement that green practices take little extra time and effort and 13 percent disagreeing with the statement that they would use more green practices if they knew more about them. Specifically, 15 percent reported harvesting rainwater or using recycled water for plants, 11 percent used drip irrigation, 29 percent planted shade trees to lower energy costs and 23 percent used maintenance methods, such as a rake instead of a leaf blower, to reduce fuel consumption, exhaust and emissions, according to the report.

Comparatively, indoors, 91 percent of respondents reported turning off lights when not in use, 70 percent installed energy-saving light bulbs, 55 percent decreased usage of heating/cooling systems and 38 percent reported unplugging appliances when not in use. “The results clearly show a desire and willingness to use techniques that reduce utility bills at home, but few know what can be accomplished outside their homes,” said Nancy Somerville, executive vice president and CEO of ASLA. “The space between buildings is just as important — perhaps more so — to not only reducing energy costs but addressing a broad range of environmental issues.”

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Authors Seek Comments on Sustainable Landscaping Report

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