Feature Article - November 2010
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Landscape Solutions

Great Grounds Advice

By Dawn Klingensmith

Greening the Landscape

While landscaping, by definition, is part of the natural environment, it also can be a drain on natural resources. The best landscaping designs and programs seek to minimize the toll it takes on the environment.

"The primary concerns are water and power consumption," said Mark Robertson, principal, Mesa Landscape Architects, Little Rock, Ark.

As such, native and drought-tolerant plant species and turf grasses should be specified as a matter of course, but oftentimes they are not. "When it comes to plant material, people are still trying to use the old favorites. They're not trying to adapt to climate- or region-specific species," Robertson said.

Rainwater, soil moisture and air temperature sensors should be used to conserve water; however, "I can't tell you how many times I've seen irrigation systems going during a rainstorm" because the systems operate on set cycles, Robertson added.

"The old rule was a regular watering cycle that was not controlled or coordinated with actual conditions," he explained.

Of course, sports fields must be maintained so as to provide a safe playable surface, and failing to do so can be costly. That there were problems with the playing surface is a complaint lodged in many lawsuits after injuries occur. But though it is necessary to water and mow turf fields, "There are new ways of irrigating them, using sub-surface drip systems, to where you're only watering the root zone and not just dumping water on top," allowing much of it to evaporate, Robertson said.

Drip irrigation as opposed to spray heads saves water and is better for plant health, he added.

Storm water can be captured and retained onsite and infiltration used instead of piping and draining.

Where there are large areas of turf that require irrigation and where conservation is a concern, site managers can undergo a landscape audit, including an irrigation evaluation. Evaluations typically include measuring the sprinklers' distribution uniformity, a soil survey and recommendations for controller settings, and projections for potential savings.

Not So Down to Earth

Robertson likes to see landscaping projects get off the ground—literally. Installing green, or vegetated, roofs benefits an entire site by managing storm water runoff, mitigating the heat island effect and encouraging biodiversity. "A well-designed living roof can capture up to an inch of water so it never even touches the ground," he said.

More and more municipalities are recognizing the importance of green roofs in the urban landscape, and studies have shown that in addition to the environmental benefits, they have longer lifespans than traditional roofs. Yet other countries are light years ahead in their design and use.

Chicago leads U.S. cities in the building of green roofs, with more than 500 projects either finished or under way. However, that number represents less than one-tenth of 1 percent of Chicago's more than half a million buildings. By contrast, 15 to 20 percent of the flat roofs in Germany are green, because local governments there have implemented regulatory incentives for building green roofs including a "rain tax" that charges property owners for impervious surfaces that allow for rainwater runoff into sewers. Toronto last year passed a law requiring all new buildings with at least 2,000 meters of floor area to cover part of their roofs with vegetation.