From Gray to Green: The Importance of Ecology in Urban Planning

Kim Chapman Applied Ecological Services

What Does it Mean to Think Ecologically About Design?The science of ecology is over a century old but only recently has it profoundly influenced the thinking of planners and engineers who design human spaces1. Although a long time coming, this shift is good for people and society. It means that thinking about maintaining and improving nature’s capacity to sustain itself and humankind is becoming mainstream. Designers who think ecologically are taking advantage of “ecosystem services” that regulate the environment and provide society with goods and services2. For example, natural landscapes purify water and regulate streamflow without human aid. When we degrade or destroy nature’s capacity to purify water and regulate streamflow, we must substitute human capital and energy to provide the same level of service. We do that by constructing and maintaining water treatment plants and stormwater management systems—substituting engineered systems at a cost for nature’s services that were free.

This paper describes a project where ecological thinking was used in the design, with positive outcomes for people and nature. One outcome of ecological thinking is to reduce the cost of the human systems by using similar services provided by nature3. For this project—a courtyard on the campus of Western Technical College in La Crosse, Wisconsin4 —it meant reducing stormwater volumes and improving water quality. That in turn translated into avoided infrastructure costs and smoother approval of the city’s MS4 water quality discharge permit. The project also enriched people’s lives by blending elements of wild nature with hardscape and engineered

systems. Before the project, the courtyard of this urban campus appeared sterile and unapproachable. By making room for nature, by increasing the variety of plant species and attracting birds and butterflies, the courtyard became a livelier, pleasanter setting, and more people used it. The courtyard also engaged college students and professors who visit it to learn and teach. These outcomes were more likely in a design process with ecological thinking than without.

Green Infrastructure as an Organizing Tool for Ecological ThinkingThe natural and naturalized parts of the urban landscape—the “green infrastructure”—contrast sharply with “gray infrastructure” of concrete, metal, placed rock, lumber and so on. Yet the role of green infrastructure in most people’s lives is underappreciated. In fact, by one estimate green infrastructure contributes some $33 trillion (1997 dollars) in ecosystem services worldwide to support the smooth running of society and the world economy5. When people can retain, restore and recreate green infrastructure, it is an investment in supporting society and economy.This idea is easy to grasp in pictures (Figure 1). In 1000 AD the human population was about 265 million. Cities, towns, crops, pastures, managed forests and fisheries took up a certain amount of land and water. At that time, the human footprint was small and the natural environment large. By 2000 AD the world population was over 6 billion—a 24-fold increase. The human footprint grew as well, taking up 33-50% of the world’s land surface and appropriating over 50% of the world’s fresh water6.

From Gray to Green: The Importance of Ecology in Urban Planning

1 Since the 1880s landscape architects have been aware of and used ecological ideas, but ecologists involved in projects add a depth of knowledge from their discipline which others have not been trained for.2 Dailey, G.C. (ed.). 1997. Nature’s services: societal dependence on natural ecosystems. Island Press, Washington DC; Costanza, R., H. Daly, C. Folke, P. Hawken, C.S. Holling, A.J. McMichael, D. Pimentel and D. Rapport. 2000. Managing our environmental portfolio. BioScience 50:149-155.3 Daily, G.C., S. Polasky, J. Goldstein, P.M. Kareiva, H.A. Mooney, L. Pejchar, T.H. Ricketts, J. Salzman and R. Shallenberger. 2009. Ecosystem in decision making: time to deliver. Frontiers in Ecology and the Environment 7:21-28.4 Western Technical College. 2011. Sustainability in grounds management. Accessed http://www.westerntc.edu/green/grounds.asp. 5 Costanza, R., R. d’Arge, R. de Groot, S. Farber, M. Grasso, B. Hannon, K. Limburg, S. Naeem, R.V. O’Neill, J. Paruelo, R.G. Raskin, P. Sutton and M. van den Belt. 1997. The value of the world’s ecosystem services and natural capital. Nature 387:253-260.6 Vitousek, P, H.A. Mooney, J. Lubchenco and J.M. Melillo. 1997. Human domination of earth’s ecosystems. Science 277:494-499.

From Gray to Green: The Importance of Ecology in Urban Planning

Figure 1. Human Footprint and the Natural Environment Through Time, with Sustainability Concept.

There is an expense to enlarge the human footprint because people must allocate capital and other resources to create and support it. With the world population projected to increase 40-50% by 2100 AD, will we outstrip our ability to afford the human-created services we must substitute for nature’s services we displace? Or will we instead preserve and even restore ecosystem services as a way to reduce our costs in creating and maintaining the human environment?Reducing that cost burden occurs at the interface between human and natural environments. The triangle, representing a balancing point or fulcrum, is where human intellect is brought to bear on the environmental challenge of human settlement.

Balance is achieved by:• Incorporating ecosystem services into design,

• Making policies that promote an ecological way of thinking,

• Modifying operations and maintenance to promote ecological functions in the landscape,

• Raising understanding of the scientific basis and consequences of ecological thinking,

• Forming partnerships.Partnerships would be between academic and non-profit institutions on the one hand, and governments and private corporations on the other. Academic and non-profit entities conduct research and execute demonstrations to find new ways of designing the human environment, while governments and private corporations shape and change the world on a vast scale.

A few examples make it abundantly clear that preserving and restoring ecosystem services

has a return on investment often better than gray infrastructure approaches. A well-known case is the decision by New York City to protect land in the Catskills in order to ensure clean drinking water sources, rather than build water treatment facilities7. Acquisition of land cost $250 million, whereas the cost to build and operate three treatment facilties was $6-8 billion. Preserving watersheds in the Catskills not only guaranteed a supply of clean water that required minimal treatment, it yielded other benefits, such as supporting local tourism. The City of Milwaukee did something similar. It hired AES to identify locations in the landscape which, if protected or restored, would manage stormwater runoff and ease downstream flooding. This became Milwaukee’s successful Greenseams program8. According to the Conservation Fund which runs the program, Milwaukee spent about $15 million to store 2,000-4,000 acre-feet of runoff at a cost of $3,750-$7,500/acre-foot. By contrast the most recent stretch of the Milwaukee Deep Tunnel, a $121 million project to manage combined sewer overflows, cost $91,000/acre-foot. The City’s $15 million investment in green infrastructure did more than manage stormwater—it expanded parkland and opened up trails. This story is being repeated across the country, with hundreds of millions of dollars being saved by not building gray infrastructure9.

While studies of return on investment (ROI) are few, there are indications that, when goods and services from ecosystems are tallied, the ROI is nearly double the investment, or more. For example, in 2010 researchers at the University of Minnesota, using an ecosystem service valuation tool called InVEST, calculated that for every dollar spent to purchase conservation land in Minnesota, $1.70-$4.40 are returned in the form of timber production, water quality improvement, outdoor recreation, habitat quality and carbon sequestration10. This ROI is invisible to managers and landowners because there is no formal market to buy and sell ecosystem services, and the assets and earnings don’t appear in capital and operating budgets.

Ecosystem services are not a panacaea, but rather a frame of reference. At the moment, few ecosystem services are even in the public consciousness. Most of those that get noticed involve water11 12 13. Moreover, not all green infrastructure projects reduce capital and operating costs. In one study, about a quarter of green infrastructure projects were more expensive than ones using gray infrastructure14.

That said, it is reasonable that bringing ecological thinking to design is a better long term approach than the alternative. That alternative starts with and focuses on engineering, landscape

From Gray to Green: The Importance of Ecology in Urban Planning

7 National Academy of Sciences. 2004. Valuing ecosystem services: toward better environmental decision-making. Water Sciences and Technology Board, National Academies Press, Washington DC.8 Garrison, N. and K. Hobbs. 2011. Rooftops to rivers II: green strategies for controlling stormwater and combined sewer overflows. Natural Resources Defense Council, Los Angeles CA; http://v3.mmsd.com/Greenseams.aspx.9 Foster, J., A. Lowe and S. Winkelman. 2011. The value of green infrastructure for urban climate adaptation. Unpublished report, The Center for Clean Air Policy, Washington DC.10 Kovacs, K.F., D. Pennington, B. Keeler, D. Kessler, J.O. Fletcher, S. Polasky, and S.J. Taff. 2011. Return on investment in conservation: an economic analysis of ecosystem services from land acquisitions by the Minnesota Department of Natural Resources. Presented at a Conference of the USDA and State Agricultural Experiment Stations: W2133: Benefits and Costs of Natural Resources Policies Affecting Public and Private Lands, Albuquerque, NM. Trust for Public Land, Minneapolis MN.11 US Environmental Protection Agency. 2010. Green infrastructure case studies: municipal policies for managing stormwater with green infrastructure. Office of Wetlands, Oceans and Watersheds, Report No. EPA-841-F-10-004. Washington DC.12 Weiss, P.T., J.S. Gulliver and A.J. Erickson. 2007. Cost and pollutant removal of storm-water treatment practices. Journal of Water Resources Planning and Management 133:218-239.13 Wise, S., J. Braden, D. Ghalayini, J. Grant, C. Kloss, E. MacMullan, S. Morse, F. Montalto, D. Nees, D. Nowak, S. Peck, S. Shaikh and C. Yu. 2010. Integrating valuation methods to recognize green infrastructure’s multiple benefits. In proceedings of the 2010 International Low Impact Development Conference: Redefining water in the city. American Society of Civil Engineers, Reston VA. Access: http://dx.doi.org/10.1061/41099(367)9814 Odefey,J., S. Detwiler, K. Rousseau, A. Trice, R. Blackwell, K. O’Hara, M. Buckley, T. Souhlas, S. Brown and P. Raviprakash. 2012. Banking on green: A look at how green infrastructure can save municipalities money and provide economic benefits community-wide. A joint report by American Rivers, the Water Environment Federation, the American Society of Landscape Architects and ECONorthwest.

architecture, and architecture outcomes. By contrast, ecological thinking begins with an explicit statement of the underlying ecosystems and ecological processes based on scientific research, and seeks to support nature as part of a sustainable development model. In time the relationship of people and nature may become mutually reinforcing and beneficial.

Ecological Thinking and the Cleary Courtyard ProjectBefore embarking on the Cleary Courtyard project, RDG Planning and Design of Des Moines had completed campus master planning for Western Technical College in La Crosse, Wisconsin. The master plan reflected the college’s vision of providing “relevant, high quality education, in a collaborative and sustainable environment, that changes the lives of students and grows our communities.” In 2008 RDG was retained again to redesign the Cleary Courtyard at the college’s Kumm Center, housing the student center and bookstore. Using ecological and hydrological engineering concepts, RDG completed a first phase of the project and laid the groundwork for the second phase. Cleary Courtyard was created in the 1970s on a vacated street next to La Crosse’s downtown. It featured a recessed seating area with a fountain that eventually was turned off. Students walking through the courtyard were forced to walk around the recessed area, navigating a narrow path near the buildings. This slowed movement or placed users in a depression surrounded by buildings. Not surprisingly, few students used the courtyard and walkers tended to bypass it in favor of easier routes.

In fall 2009, RDG invited AES to participate in a kick-off meeting for the second phase of Cleary Courtyard, also known as the Kumm Center Site Development. AES was represented by

Senior Engineer Gary Paradoski and Principal Ecologist Kim Chapman, who were instrumental in renewing an emphasis on ecological thinking. RDG was led by Ryan Peterson, the project director and landscape architect, Mike Bell the campus planner, and Doug Adamson who led the conceptual design effort for the entire project. Heather Kieweg of AES was responsible for native species planting plans. Western Technical College was represented on the design team by Mike Pieper, Vice President of Finance and Operations.

From the outset, ecological concepts were central to the design process. At the kickoff meeting, AES discussed the ecological concepts that could be incorporated in the design and function of the courtyard. The most obvious was to restore ecosystem services of the water cycle. This meant increasing infiltration and evapotranspiration, and reducing surface runoff. At Cleary Courtyard, a 60-inch storm sewer serving the area was at capacity. The addition of impervious cover—a building extension and new courtyard paving—had the potential to exceed the pipe’s capacity. The City required that after construction, the 2- and 10-year storms not exceed the existing runoff volumes from the site.

Another idea was to treat the street as river and floodplain. Runoff from the site flowed north to the La Crosse River and west to the Mississippi. The courtyard’s west edge was bounded by 6th Street, an urban streetscape of buildings and parking lots. Water in the street flowed north and south where the east-west running courtyard intersected the road. Shunting runoff water from the street gutter into planters sunk in the boulevard next to the street simulated how water overtops streambanks in flood stage and enters floodplains. There water is slowed, temporarily stored, and cleansed of some pollutants, especially sediment, before being returned to the

From Gray to Green: The Importance of Ecology in Urban Planning

stream (or the street gutter). This idea has been widely implemented already, in Portland most notably, but not to our knowledge in the guise of replicating floodplain functions.

Habitat loss and fragmentation is a major cause of species extinctions and endangerment. The production of fish and wildlife, an ecosystem service, is short-circuited by habitat loss and fragmentation. While no endangered species would be helped by repairing habitat in an urban setting, species otherwise absent from urban spaces might take up residence there, given the right conditions. In small, tight spaces like Cleary Courtyard, species that require large habitat patches—most warblers, vireos, flycatchers, thrushes and grassland birds, for instance—are not favored, despite improved habitat. For these reasons, AES discussed the idea of habitat islands to serve as stepping stones through the urban core. Habitat islands, if populated by a diverse array of native plant species and placed near enough to each other, could establish pathways to attract butterflies, dragonflies, and birds from nearby wild areas.

Lastly, the ecosystem services of microclimatic cooling and wind sheltering are sharply curtailed in urban settings. The well-known urban heat island effect produces high night-time temperatures in summer, forcing people to use air conditioning to sleep well at night. A significant countervailing force to the urban heat island effect is vegetation mass, which is low in urban and suburban settings compared to natural ones. From an ecological standpoint, urban and suburban landscapes are simplified grasslands and savannas with buildings. Tree canopy cover ranges from 5-30%, only a few dozen species make up the planting palette, and a shrub layer is largely absent. The well-documented microclimate cooling of forests is largely due to shading of the ground, which reduces ambient air temperatures because light energy is not

converted to heat when it strikes the ground. Rather most is reflected to the sky or converted to energy by plants. Vegetation mass can also reduce wind speed by converting the energy of wind to mechanical energy in the movement of leaves and stems. At Cleary Courtyard, cooling and wind-sheltering by increasing shading and vegetation mass would improve the microclimate for people.

The design emerging from this ecological thinking was innovative enough to win three planning awards: an ASLA Iowa Chapter Honor Award, an ASLA Wisconsin Chapter Merit Award for Construction, and an ASLA Central States Merit Award. Ecologists would say that the design replicates aspects of ecologically healthy natural systems to deliver a higher level of ecosystem service than is possible in an urban setting by using gray infrastructure alone.

Project DevelopmentAfter the kick-off meeting, the RDG-AES team met with engineers and planners from the City to propose a green street where 6th Street met the Courtyard. Seeing a chance to advance best practices under the City’s MS4 permit, and having considered a similar idea earlier which did not move forward, City staff was open to the concept. College officials also saw the ecological proposals as advancing the College’s intentions to promote an image of innovation in sustainability and technology, as well as to create an example for future projects to emulate.In the first phase of the project, ecological thinking was already being emphasized. As the second phase began, AES conceptualized new ideas to promote stormwater management, habitat connectivity, and ecological processes.

During the design process AES’s ecologists and engineers developed ideas which RDG staff incorporated into conceptual designs. The most

From Gray to Green: The Importance of Ecology in Urban Planning

significant was stormwater management. An early idea, a green roof, was rejected for several reasons. The RDG-AES team also estimated that stormwater from the new building and pavement could be managed in two raingardens, with permeable pavers in the courtyard and pervious asphalt in a loading area. A hydrological analysis determined that the new system would reduce total volume entering the 60-inch pipe by 78% from pre-construction conditions. In effect, the project increased the capacity of the gray infrastructure by restoring green infrastructure. AES engineers estimated that raingardens and street planters would remove between one-third and two-thirds of the sediment and phosphorus from surface runoff because the most polluting first flush of runoff would enter a vegetation-soil matrix which is effective in removing these pollutants. Underdrains were installed in the raingardens and boulevard planters to maintain dry soil conditions. In a saturated condition the raingardens and planters do not manage runoff as effectively.

Habitat islands were designed with a diverse but manageable planting palette of native species: 10 species of trees and shrubs, 14 grasses, sedges and rushes, and 33 wildflowers. AES ecologists selected species that met criteria for ecological functionality, design and aesthetics, wildlife values (e.g., seed and nectar production), and ease of maintenance. The site was classified into solar radiation zones (shade, partial shade, full sun) and plants distributed according to shade and sun tolerance. An early idea of using coniferous trees to shelter the windiest part of the courtyard was discarded because the trees would limit visibility. Plants in the boulevard planters had to withstand winter salt applications, and raingarden plants

were selected to withstand periods of temporary ponding.

OutcomesAfter the courtyard was constructed, use of the space increased dramatically. College and design team staff note that not only do students and faculty gravitate to the courtyard, but so do birds, butterflies and pollinators. Horticultural students use the site to learn about the plants in their various ecological settings. And townspeople who used to avoid the courtyard now go out of their way to walk through it. To advance the college’s educational mission, RDG created several displays which describe the stormwater management system and native plantings.

On August 11, 2011, the City passed the first ordinance in Wisconsin requiring that road projects be designed using complete and green street principles. The City’s planning director, Larry Kirch, told the RDG-AES team that the City’s experience with the Cleary Courtyard project and 6th Street planters were instrumental in the decision. The College, too, sees the project as a bricks and mortar (and plants and soil) commitment to create a more sustainable environment15, just as envisioned by the master planning that started the whole design process.

From Gray to Green: The Importance of Ecology in Urban Planning

15 Western Technical College. 2011. Sustainability in grounds management. Accessed http://www.westerntc.edu/green/grounds.asp.