Eco-Cities
Content Table
Introduction
This article presents concepts and synthesis of ecocity developments, using Hammarby Sjöstad in Sweden, Dongtan, Tianjin and Qingdao in China, Masdar in the United Arab Emirates and Treasure Island and Sonoma Mountain Village in California as case studies. An ecocity is a city or a part thereof that balances social, economic and environmental factors (triple bottom line) to achieve sustainable development and results in a minimal or no adverse ecological or carbon footprint. With exception of Dongtan, these ecocities are in various stages of development and realization. Dongtan’s development has stalled because of political reasons. Tianjin is a joint project of China and Singapore. Two developments, Masdar and Sonoma Mountain Village have applied for One Planet Living (OPL) community certification.
The majority of the investigated ecocities were medium density communities. The concept of cluster development and ecoblocks were introduced and discussed. Dongtan, Qingdao, Masdar and Sonoma Valley designs are proving that ecocities can fulfill the OPL criterion of zero green house gas emissions from infrastructure heating, cooling, electricity consumption and traffic. All cities use the latest technology for in-house water savings such as low flush toilets, showers, etc. Ecocities use surface drainage for collecting urban runoff and clean water inputs and implement extensively best management practices for urban runoff such as pervious pavements for infiltration, capture and storage in underground basins, and reuse for various purposes such as irrigation, fire protection, and plan to tap into their groundwater resources for reclaimed water.
The analysis has revealed some problems with the lack of macroscale measures, models, and indices for some key components of the triple bottom assessment. Several research hypotheses and ecocity concepts were suggested for further research and studying.
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General Concepts
The original and most frequently quoted definition of “sustainable development” comes from the Brundtland et al. (1987) report of the World Commission on Environment and Development
“Development that meets the needs of the present without compromising the ability of future generations to meet their own needs”.
The terms “sustainability”, “sustainable development” and adherence to their principles is the historical shift from “a maximum economic use model” that perceived resources to be merely raw materials for production and sinks for the disposal of waste, to an optimal model that recognizes the environment as a finite resource needed to be conserved through governmental regulation in order to create a “long – term relationship between the economy and nature” (Dilworth, 2008). However, Mihelcic et al., (2003) pointed out sustainability is not merely a preference for economic development with some environmental protection (an anthropogenic development view) or preserving nature with “green” low impact low imperviousness development (a biocentric view). It is a megascience defined as a design of human and industrial systems to ensure the development and use of natural resources do not lead to diminished quality of life due to either losses in future economic opportunities, or adverse impact on society, human health, and the environment. The time point of reference must be added to these concepts.
It is now generally agreed the present urban water/stormwater/wastewater systems are not sustainable and there is a need to change the paradigm for how to efficiently build and operate cities. Many cities, especially in the developing world, cannot provide an adequate amount of water; also water provided during a few hours in a day is contaminated by cross-connections with sewers due to low pressures and damaged pipelines. Urban pollution is still very high in many cities. China, for example, due to its tremendous economic and environmental unrestricted growth, had in 2006 six out of thirty most polluted cities in the world (Blacksmith Institute, 2007), yet, it needs to build in the next twenty five to thirty years new cities for a population of about 300 million people. Even in developed countries, the urban environmental infrastructure is crumbling and will require massive investments for repairs but no matter how many billions will be spent to rebuild in the old way, cities will not be sustainable and the environmental goals will not be met. Furthermore, urban water supplies are threatened by nutrients resulting from excessive fertilizer applications in intensive agriculture and on suburban lawns (Novotny, 2007). Excessive nutrients in many parts of the world stimulate dense algal blooms of cyanobacteria (blue green algae) exhibited by a pea soup water quality that renders reservoirs and lakes unsuitable for water supply, recreation, and maintenance of balanced aquatic biota (Novotny, 2009). Cyanobacteria prefer warmer conditions; hence, frequency of occurrence of noxious cyanobacteria blooms may increase with global warming.
The current unsustainable situation will be further exacerbated by:
- population increases (urban population is expected to increase by 50 % in the next 20-30 years; many new cities will be built in Asia and other parts of the world);
- increasing living standard (more demand on food and, consequently, water resources); .• global warming (increasing sea levels, changes in drought and water availability patterns) (ICPP, 2007) .• emerging new pollutants (endocrine disruptors, pharmaceutical residuals; more frequent massive cyanobacteria bloom outbreaks);
- increasing water scarcity, currently about 0.7 billion people experience true water scarcity, they live on less than 25 litres per person per day which is expected to grow to more than 3 billion of people by 2025 if nothing is done (Zhang, 2007);
- conversion of urban waters into effluent dominated water will require management of the total urban water hydrological cycle and decentralization of urban sewerage;
- increased flooding due to global warming effects, increased imperviousness and other land use changes in the watershed;
- energy shortages due to less oil,; production of biofuel from corn and other crops increases food prices.
The concepts of the new paradigm of sustainable water centric ecocities have been emerging for the last fifteen years in environmental research and landscape design laboratories in several countries in Europe (Sweden, Germany, United Kingdom), Asia (Singapore, China, Japan and Korea), Australia, USA (Chicago, Portland, Seattle, Philadelphia, San Francisco area) and Canada (British Columbia, Great Lakes area). This paradigm is based on the premise that urban waters are the lifeline of cities and focus of the movement towards more sustainable cities. The evolution of the new paradigm of urbanization is ranging from the microscale “green” buildings, subdivisions or “ecoblocks” to macroscale ecocities and ecologically reengineered urban watersheds, incorporating also transportation, food production and consumption and neighborhood urban living. This expanded concept might lead to “ecoregions”, i.e., sustainable regional development that would include urban living spaces and sustainable (organic) suburban agriculture and nature areas. All concepts developed by landscape architects incorporate surface water bodies as a focus and water management. At the same time, environmental engineers and urban planners are developing water/stormwater/wastewater management concepts based on a change from the linear once through water management (minimum reuse) to a closed hydrological cycle system that maximizes reclamation, reuse and recycling. Reduction of green house gas (GHG) emissions has become a major social goal in the last five years. The third component of the ecocities/cities of the future is application of green technologies. Table 1.1 (Valerie Nelson, personal communication) lists major differences between the current unsustainable paradigm and the new paradigm as it is emerging in concepts and reality in Europe, Asia, Australia and North America.
Water Centric Developments
Water centric developments recognize the ecological value of surface water resources first. In this approach the ecological integrity of the water resources and riparian and flood zones is preserved or restored, using integrated resource management which also considers the impact on GHG emissions. Integrated resources management of water centric cities will consider;
1) Water conservation (green development);
2) Distributed stormwater management using best management practices of rainwater harvesting, infiltration and storage of excess flows, and surface drainage;
3) Distributed wastewater treatment generating water for reuse in buildings, landscape irrigation and ecological flow of existing or restored water bodies;
4) Using landscape and landscape components (e.g., ponds, wetlands, grass filters, etc.) for attenuation of diffuse pollution and post treatment of effluents recovered for reuse;
5) Heat and energy recovery,
6) Nutrient recovery,
7) Biogas production, and
8) Degree of use of alternate renewable energy sources.
Sustainable development based on the triple bottom assessment and evaluation will balance in an intergenerational context social equity that recognizes the needs of all members of the society (e.g., public health, reduction of GHG emissions, recreation and leisure time), economic development ensuring economic growth and employment, better life for the society today and in the future, and protect and enhance the quality of the environment. This also implies if the current and near past generations have damaged the environment or distorted social equity for the sake of development, a new triple bottom relationship must be achieved to restore the balance for future generations. The time has come to critically evaluate what has been developed during the last twenty five years in the field of urban drainage and diffuse pollution abatement according to green city concepts and create a new approach to drainage and building/retrofitting the cities to mimic nature and the pre-development hydrology. Other trends can also be considered such as reducing or eliminating GHG emissions from buildings, vehicles and improved public transportation by reducing urban/highway pollution. Table 1.2 presents the components and features of the new 21st century urban water/stormwater/ wastewater sustainable systems.
Resources
This article is an extract from the report, Sustainability and International Innovation, by Valerie I. Nelson, Jerry Stonebridge and Steve Modemeyer
This report presents updated work from eight of the key speakers at the 2007 international conference Water for All Life: A Decentralized Infrastructure for a Sustainable Future. Each chapter represents a major thread in the new fabric of understanding of water sustainability that became embodied in the Baltimore Charter which was drafted following the conference. In addition to chapters on a new water management paradigm, new technologies and tools for sustainability, and institutions and barriers, the report includes a chapter on eco-cities as well as resource directory of international experts. A final chapter is included on prospects for innovation in the United States.
