develop a Leed rating system for neighborhood development. Called Leed-nd, it
integrates the principles of smart growth, urbanism and green building into.
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Benefits of New Urbanism Traditional neighborhood developments offer several environmental benefits, including a reduced reliance on automobiles. The United States Green Building Council (USGBC), which developed the Leadership in Energy and Environmental Design (LEED) green building rating system, has recognized this fact. In partnership with the Congress for the New Urbanism (CNU) and the Natural Resources Defense Council, the USGBC used the principles of New Urbanism to develop a LEED rating system for neighborhood development. Called LEED-ND, it integrates the principles of smart growth, urbanism and green building into the first national standard for neighborhood design. Georgio Tachiev, Ph.D., an environmental engineer and professor at Florida International University, also confirms the significant environmental benefits of New Urbanist neighborhoods.. He stresses the environmental benefits of the minimal impactNew Urbanist neighborhoods can have on watersheds, the drainage basins that occur on a national, I17
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The Light Imprint approach to stormwater management is rooted in New Urbanism which promotes traditional neighborhood design. These walkable, connected developments are an alternative to sprawl. New Urbanists take a proactive, multidisciplinary approach to restoring our existing communities and creating new urban environments. New Urbanists include planners, developers, architects, engineers, public officials, investors, and community activists who create and influence the built environment. Their work transforms growth patterns. Whether they are turning dying malls into vibrant mixed-use neighborhoods, connecting isolated public housing projects to surrounding neighborhoods, or bringing restorative plans to disaster-stricken communities, New Urbanists are leaders in building communities. New Urban design techniques take into account the general principles that make pleasant, livable, and environmentally friendly communities. These principles are outlined in the Charter of the New Urbanism (see http://www. cnu.org/cnu_reports/Charter. pdf) The Charter gives priority to principles of diversity, walkability and connectivity. All of these contribute to the creation of sustainable neighborhoods. The development industry has begun shifting from the conventional suburban model towards the New Urbanist one, which has compact, connected, mixed-use,
pedestrian-friendly communities. This shift reflects the need to better address the environment; it is an effort to combine the goals of community leaders, planners, developers, and land conservation organizations. Sprawl inevitably leads to excessive land use and automobile dependency. New Urbanist development offers a far more sustainable alternative.
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Conventional Suburban Development - Potentially incorporates green, but is still conventional sprawl.
regional, neighborhood, and block levels. In a statement, the Environmental Protection Agency (EPA) says, “Watersheds supply drinking water, provide recreation and respite, and sustain life. More than $450 billion in food and fiber, manufactured goods, and tourism depends on clean water and healthy watersheds.” According to Dr. Tachiev, New Urbanist developments perform well on a regional scale for two important reasons. First, compact communities reduce stress on watersheds by decreasing the volume of runoff from impervious surfaces such as roads. Second, regional infrastructure is reduced in compact communities. Conversely, communities develop e d u sing conventional suburban techniques will have excessive land use encouraged I18
by their sprawling nature. Additional impervious surfaces found in sprawl lead to interruption of water flows and increases in amounts of pollutants in runoff. Both of these cause damage to watersheds. Ultimately, sprawl impairs the services and resources provided by the watershed. Dr. Tachiev explains that the networks advocated by the New Urbanist development model create connections between the built and natural environments. He says, “The methods we apply to design our built environment affect the balance of environment, society, economy, and energy. From an engineering point of view, New Urbanism is a methodology that implements sustainability in all four aspects. When discussing sustainability, we need to emphasize watersheds since they are Light Imprint Handbook
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Traditional Neighborhood Development on the Town & Country Planning Model is both green and sustainable.
the natural containers hosting the human habitat. Because its compact form allows more of a watershed to be maintained in its natural condition, New Urbanism ensures that watersheds can continue to give high quality services. These services include biodiversity, water quality and quantity, and assimilative capacity [the amount of water the watershed can contain].”
Light Imprint & New Urbanism The framework for New Urbanist design provide clear benefits to the environment. When applied comprehensively, it is an intrinsically green design strategy, with a compact, connected form that respects nature. New Urbanist planning, however, is sometimes criticized Light Imprint Handbook
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for not being environmentally friendly enough. Light Imprint develop ed out of a need to coordinate engineering concerns with New Urbanist design principles; it makes stormwater management in traditional neighborhoods even more environmentally friendly. LI enables developers to give more consideration to environmental factors without compromising design. Like all New Urban planning, LI respects a site’s terrain. It recognizes the importance of public civic spaces and connectivity. Additionally, LI offers a range of environmental strategies, from time-tested to cutting-edge, for differing landscapes and urban conditions. LI introduces a tool set for addressing stormwater runoff through natural drainage, conI19
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ventional engineering infrastructure, and innovative infiltration practices. These tools are used jointly at the sector, neighborhood, and block scale. LI organizes this information by dividing the landscape into sections representing urban to rural conditions (called the transect). More than sixty Light Imprint tools and resources are clearly organized in a matrix according to the appropriateness of their use in each zone. The matrix includes the urban to rural (transect) conditions, initial costs, long term maintenance factors, soil hydrology, slope conditions, and climate. This toolset can also significantly lower construction and engineering costs. When LI tools are used in conjunction with traditional engineering methods, they can reduce the need for the typical solution of inlet, pipe, and pit infrastructure. LI advocates that stormwater be returned to the aquifer without channeling it far from its original location. This contrasts with conventional engineering that directs water to an inlet, where it flows through a pipe, and is released into a pit at the back of the site.
Critique of New Urbanism As the development industry shifts to a more environmentally conscious outlook, many organizations have begun promoting their own environmental techniques with frameworks set up by different development practices. These techniques are sound in individual situations, but few offer I20
the comprehensive approach that New Urbanism provides. Even if planners and developers choose to use one of these other overall approaches, they can still dip into the LI toolbox. Leading planner Andres Duany, a founder of Duany PlaterZyberk & Company, describes the layout of a typical New Urban community as an open-mesh network where a system of connected streets mitigates traffic congestion and reinforces community connections. By emphasizing these design and planning issues, New Urbanist development offers multifaceted environmental and community planning benefits, unlike more isolated environmental approaches. Since LI is based on these planning principles, it differs significantly from other development approaches.
Green Urbanism Green Urbanism (GU) is an environmental approach initially promoted in the United States by landscape architects attempting to design more ecologically stable communities. Green Urbanism is often considered a more environmentally viable alternative to New Urbanism. It emphasizes an increased amount of open space on a development site, usually sixty percent or more per project. In GU, greenway fingers serve as the organizing spines for the development, and stormwater filtration mechanisms are placed outside of and around these green spaces. When compared with New Urbanist developments, Light Imprint Handbook
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Low Impact Development (LID) is another popular environmental development strategy. It attempts to manage stormwater quality by using both onsite design techniques and Best Management Practices (see below). Well-intentioned municipalities may have adopted or currently be in the process of adopting the Low Impact Development (LID) approach without understanding the conflict between stormwater management tools and sustainable community design. The primary concern with LID is its origin in conventional suburban development. LID techniques can be applied without significant variation to conventional suburban residential developments, conventional suburban commercial developments, and even to some urban areas with suburban characteristics (such as Portland, Oregon, and Seattle, Washington). LID offers similar approaches and techniques for suburban models of low-density subdiviLight Imprint Handbook
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Best Management Practices For addressing methods of stormwater treatment, Best Management Practices (BMP) focus on engineering rather than planning and design. Though smart growth techniques are not always sucI21
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sions, high-density apartment complexes, and strip shopping centers. This lack of distinction between developments of different characters is one shortcoming of LID. Residents of all conventional suburban development rely heavily on their automobiles for transportation to provide daily needs. Any attempt to make these developments environmentally friendly ignores the larger issues of carbon dioxide, fuel, and congestion. From a planning and sustainability perspective, clusters of single-entry housing cul-de-sacs, though they save tracts of open space, are not the best solution. A better strategy is to weave compact, walkable, connected neighborhoods into the larger community. Finally, without intensive calibration, LID may actually prevent sustainable development. Many of its standards and practices involve lot-based, rather than block- or neighborhood-based, solutions; that increases the need for large lots. For instance, despite their environmental benefits, putting rain gardens in front of houses increases the front setback significantly. To foster walkable urbanism, the houses need to be close to the sidewalk.
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Green Urbanism developments are less connected; it is a compromise in social and community connectivity. A second problem is that reserving significant open space reduces the amount of developable land. Thus the project may not be economically viable. Recently GU has evolved towards promoting excellent European examples of compact development, but still suffers from the initial perceptions within the industry.
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Green Urbanism may conserve significant amounts of open space, but it isolates residents into income segregated tracts.
Green Urbanism emphasizes an increased amount of open space and green connection, but compromises community walkability and connectivity.
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INTRODUCTION Principles Light Imprint planning weaves development into the existing natural environment, providing both sustainability and community connectivity.
TND Plans with a Light Imprint focus weave community design and nature, providing useable open space.
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Suburban retail with Low Impact (LID) standards has green space, but compromises walkability and connectivity between businesses.
Low Impact Development (LID) tools intended for suburban development apply rain gardens on sprawling front lawns.
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INTRODUCTION Principles A Light Imprint urban design, along with being green, readily conforms to community walkability and connectivity between businesses.
In walkable communities with compact yards, a Light Imprint communal rain garden is applied to serve a group of homes.
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This conventionally engineered suburban parking lot has excessive and costly infrastructure to support its rain gardens.
This grate inlet skimmer box is an expensive and high maintenance method of filtering stormwater. These tools are generally categorized as high-tech green solutions.
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This Light Imprint parking lot provides a low tech solution using pervious stone. It is beautiful with or without vehicles.
This vegetative and stone swale leading to a filtration pond is both a beautiful and more economical method of channeling and filtering stormwater. Light Imprint tools are generally categorized as intrinsically green tools.
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cessful, the EPA proposes using them as a BMP for stormwater management. For example, compact development suffers when the BMP techniques result in stormwater detention areas in front of or beside buildings. This approach prevents social connectivity. In addition, shop owners find that detention areas in front of their buildings interfere with the customers’ access to goods and services.
Other Environmental Initiatives Light Imprint supports other environmental initiatives for planning, development, and infrastructure implementation. It supplements LEED-ND, Sustainable Sites, and the EPA Smart Growth Initiative.
New Urbanist Conventional Engineering New Urbanist Light Imprint engineering deviates from conventional engineering practices. It can accommodate more of the development standards necessary for community-oriented design, which include smaller lots, narrower streets, and more alleys. Municipalities reviewing development plans are often interested in embracing the New Urbanist approach. Their governing bodies, however, may be concerned about accepting different zoning standards. The Light Imprint approach offers a broad, comprehensive framework. Other problems occur when designers and engineers attempt I28
to overcompensate for preceived stormwater management deficiencies by increasing infrastructure standards and design criteria. This overcompensation, or gold plating, of infrastructure can be a deterrent to the successful implementation of a New Urban community. Project delays, duplication of tools, and additional infrastructure cost can ultimately prevent the realization of good community development.
In Summary: Light Imprint Benefits and Next Steps Light Imprint offers a more manageable alternative to Green Urbanism, Low Impact Development, and BMPs by combining innovative engineering practices with the New Urban design approach. LI uses a variety of tools appropriate for specific transect zones, installation costs, maintenance costs, climate, slope, and hydrology (soils). Instead of limiting itself to one environmentally sensitive development approach, LI offers a set of contextually appropriate design solutions. This strategy simplifies design decisions and implementation, a crucial advantage, as only a limited number of New Urbanist practitioners have significant implementation experience. According to Georgio Tachiev, Ph.D. LI reduces the amount of infrastructure such as roads, public works, and facilities that are needed at the neighborhood scale. On the block scale, the implementation of light imprint methods reduces stormwater runoff by decreasing the overall footprints Light Imprint Handbook
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of buildings. This enhances the community both aesthetically and environmentally. The next step for Light Imprint is broad acceptance by planners, engineers and municipalities. Stephen L. Davis, P.E., of Davis & Floyd Engineers, is an enthusiastic supporter of Light Imprint. He tempers it, however, with a realistic long range outlook. Davis says by “ground truthing,” it is possible to determine how practical it is to get Light Imprint communities approved by municipalities and then actually built. Davis explains, “Standard engineering methods are quicker to complete and easier to submit for permits for processing. In order to have the Light Imprint approach embraced by advocates of New Urbanism within municipalities and the development and building industry, it is important to have the LI model presented as a comprehensive strategy.” Ultimately, the success or failure of Light Imprint is measured by its life. The ability of a community built with Light Imprint ideals to function, flourish, and endure is the gauge by which it – and by extension, Light Imprint – will be judged a success.
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