Architecture News

Landscape Architects Play Central Role in Green Design

By Nadine M. Post

Need to stop flooding or reduce stormwater runoff and sewer overflows? Looking to ease demand on treatment plants and avoid the cost of expansion? Seeking cleaner air or water? Interested in recharging an aquifer, rebuilding a shoreline or remediating a brownfield? Trying to stem highway pollution? Need to rebalance a watershed or ecosystem?

Houston’s buffalo bayou transformation turns derelict channel into urban paradise(top). The city’s Buffalo Bayou project involves re-engineering banks, stabilizing soil, anchoring rock and more. The park is designed to withstand natural periodic flooding (above).

If so, a landscape architect may be in your future. The design professional—until recently derided as little more than a glorified gardener—is on a campaign to reclaim a seat at the environmental cleanup table. Some are even bent on sitting at the head, leading the engineers.

The movement is variously called performance-based, ecological, sustainable or green landscape architecture. Some use the terms “landscape infrastructure” or “landscape urbanism”. A rose by any name would smell as sweet, not only to landscape architects, long suffering from low self-esteem, but to localities seeking economical, less invasive and more beautiful ways to deal with the poisons of development.

This form of landscape architecture harks back to the profession’s roots. In a decade, it has gone from “obscurity to mainstream,” says David Yocca, a principal in the Elmhurst, Ill., office of Conservation Design Forum, a planner, landscape designer and engineer.

This dramatic change signals a comeback for a group that had lost its way in the 1980s and 1990s. During that time, within the profession, there was a “backlash against environmentalism and a view that the environmental movement had shorted esthetic concerns,” says Fritz Steiner, dean of the School of Architecture at the University of Texas, Austin. On the contrary, “environmentalism and esthetics are complementary,” he says.

Even geotechnical engineers, who often work with landscape architects, see the discipline’s renaissance. “We were absolutely not doing [ecological landscape architecture] 10 years ago,” says Christopher A. Robertson, a vice president at Shannon & Wilson Inc., a Seattle-based geotechnical and environmental consultant. “It is where stormwater management is headed,” he adds.

Landscape architecture, a discipline that combines nature, culture and technology, in no measure eliminates the engineer from the equation. “We have to move forward holistically,” integrating design and engineering, says Bert Gregory, CEO of Mithun, a Seattle-based architect, landscape architect and planner.

The landscape profession is growing, numbering about 30,000, including 15,000 who are licensed. Employment of landscape architects through 2014 is expected to increase 18% to 26%, faster than the average of all U.S. occupations, according to the Bureau of Labor Statistics. By contrast, BLS estimates, demand through 2012 for architects, planners, interior designers and environmental scientists will grow an average of 9% to 15%. Demand for civil engineers is expected to grow at a slower-than-average rate of 0% to 8%. Membership in the American Society of Landscape Architects (ASLA) grew from 16,586 in 2005 to 17,236 in 2008. And this year, U.S. News & World Report named landscape architecture as one of its 30 best careers.

From green roofs and green streets to waterfronts and watersheds, from exurbs to “urbs,” landscape architects are helping turn eyesores into eyefuls. They are using a combination of natural and engineered systems, including soil biofiltration and carbon sequestering, that manage and clean water and air. Permeable pavements and bioswales—depressed planters that soak up and filter stormwater runoff polluted with oils and metals—are starting to pop up in parking lots and along streets from Portland, Ore., to Philadelphia. Green roofs that absorb stormwater, insulate buildings and reduce the urban heat-island effect, are proliferating across the nation. In Houston, a derelict stormwater channel is becoming a public park. Durango, Colo., has a sustainable golf course.

Local food production through urban and suburban farming is on the horizon, much under the stewardship of landscape architects. TSR Group, which has been plowing through zoning obstacles to manage development of 3,000 acres of planned farm towns, even trademarked a word for sustainable suburban farming: Agriburbia.

“We believe we will make the suburbs useful in their own right, not just for commuting,” says Quint Redmond, CEO of Golden, Colo.-based TSR

Landscape architects are not the only ones tooting their horns. “We recognize we cannot make our sewer and water pipes big enough” to handle loads, says Howard Neukrug, director of Philadelphia’s office of watersheds. “For water issues, it is critical to have the landscape architect involved early in the process. How you site a building—even your first imagination— will help determine how sustainable a building will be,” says Neukrug.

Taking Cover

Philadelphia, which defines green infrastructure as anything that captures the first inch of rainwater, has new street-greening standards. The goal is to remove 50% of impervious cover in 20 years. The inspiration for the program came in 2000 from a landscape architecture professor, Anne Spirn, now at MIT, who was at the University of Pennsylvania in West Philadelphia. Spirn had ideas for the area’s renewal. “We put her in a van with civil engineers, went to a site, and she gave us a vision,” says Neukrug.

Planners also support the landscape architects’ comeback. They bring “very valuable skills to the team,” says Joe MacDonald, a senior associate with the American Planning Association.

Even engineers are warming to the idea of the landscape architect. Neukrug says it is “fun” to watch the marriage of the professions. “They are both so creative in different ways,” he says, adding that it may be a forced marriage at first, but resentment decreases as parties work together. Engineers have “secretly” always wanted to handle things differently, says Neukrug, an engineer.

Landscape architects are getting assertive. A decade ago, “we would accept the engineer’s solution,” says Jeff Zimmermann, a principal in the Denver office of Design Workshop Inc., which designed the sustainable Glacier Club golf course, in Durango, Colo. “Today, we are more critical, knowing there are ways to step more lightly on the land,” he adds.

Kevin Shanley, CEO of landscape architect-planner SWA Group, wants the landscape architect to lead the team, not just be on it. Low-impact development involves living things that landscape architects, not engineers, are trained to consider, says Shanley, in SWA’s Houston office. Landscape architects need to get involved politically to push landscape infrastructure, he says.

One example is Houston’s Buffalo Bayou project, a public-private partnership downtown, planned and designed by SWA. The shores of the derelict stormwater channel are becoming 850 acres of public green space and trails. Fund-raising and initial planning for the second phase is starting. The first 3,000 lineal ft, called Sabine-to-Bagby, was completed in 2002 for $15 million. During last year’s flooding caused by Hurricane Ike, the area performed better than expected, says SWA. There was minimal damage, and the park was back in service in a couple of days. Properly built, storm channels can be parks most of the year, says SWA.

The firm also is involved with reforesting highway corridors to sequester carbon, improve runoff, build habitat and look good. “Infrastructure needs to provide multiple benefits,” says Shanley.

Depending on the project’s details, a sustainable landscape can cost anywhere from $25 to $50 per sq ft on ground to $200 per sq ft on structure. Landscape architects charge from $70 to $120 per hour, or 5% to 15% of the project’s cost.

How did society get into this fix of fractured infrastructure? Sources say the big culprits are development and very strict interpretation of Euclidian zoning, which rigidly segregates land uses. “We have been isolating land uses in favor of an auto-centric development model in the U.S. for almost 80 years,” says Curt Johansen, executive vice president of developer Triad Communities, Vallejo, Calif. “That must end immediately,” he says.

It has taken five years for Triad to get zoning approvals for its 350-unit Angwin Ecovillage, a sustainable farming community in Napa County, Calif., currently under environmental review.

Also over the past 50 years, high-impact building and roadway development have reduced the amount of permeable surface to accept stormwater, increasing flooding and pollution. Stream flow speeds in Houston, for example, have increased from under 5,000 cu ft per second in 1930 to about 27,500 cfs in 2000, says the U.S. Geological Survey. With stream-flow increases come a greater potential for flooding. The actual stream flow from 2001’s Tropical Storm Allison in Houston’s Brays Bayou peaked sharply at about 34,000 cfs, 20 hours from the start of runoff. This compares to a more gradual stream flow in 1915, before development (see graph, p. 87). Allison, which caused $5 billion of damage in Houston, would have been a nonevent even 50 years ago because the natural landscape would have absorbed the water, say sources.

Planting Seeds

Seeds for the landscape infrastructure movement were planted during the environmental movement of the late 1960s. The 1972 Clean Water Act mandated control of point-source water pollution. Stormwater is part of that equation because of combined sewer overflow (CSO) systems in many cities. Years into CWA, it became clear nonpoint-source pollution—stormwater runoff in general—had to be addressed to meet clean-water goals. In the 1990s, cities, under threat of fines as a result of regulations to limit stormwater runoff, started seeking economical ways to handle it.

Another impetus for sustainable landscape has come from the U.S. Green Building Council’s green building-rating system, called Leadership in Energy and Environmental Design (LEED). Introduced in 2000, the tool soon focused attention on sustainability, including site issues. “If it were not for LEED, this would not have happened as fast,” says ASLA CEO Nancy Somerville.

But LEED was too building-centric for landscape architects. So ASLA decided to develop its own rating system, called the Sustainable Sites Initiative (ENR 11/17/08 p. 16). SSI is an interdisciplinary effort of ASLA, the Lady Bird Johnson Wildflower Center and the United States Botanic Garden, with support from USGBC and others. The goal is to create voluntary national guidelines and performance benchmarks for sustainable land design, construction and maintenance practices. Guidelines are expected later this year. The SSI rating system is due out in 2011 and a reference guide in 2012. SSI is designed to be used by itself but will be incorporated into LEED. Information is available at www.sustainablesites.org/.

Zoning is not the only obstacle to sustainable landscape. Initially, there was no proof the systems work. There was concern about maintenance and general resistance to change. “Just trying something new has its obstacles,” says Kevin Perry, a stormwater specialist with Nevue Ngan Associates, Portland, Ore. Perry designed the first green street in 2003 for Portland, a pioneer in this area.

Consequently, most projects have redundancies. Thomas R. Tavella, president of the Hamden, Conn.-based landscape architect that bears his name, does not mind if there is still a catch basin in the corner. “It is OK to have redundancy. It is part of the education process,” he says.

Recent research, such as field work at the University of New Hampshire Stormwater Center, demonstrates green streets and roofs manage and clean stormwater. Consequently, municipalities are becoming strong proponents, say sources.

More significantly, green landscape architecture is causing a fundamental shift in how design occurs. Karen Janosky, a Mithun associate principal, sums it up: “It is an amazing era and an incredible time to go into landscape architecture.”