The seven key innovations of resilient cities are set as city models (being detailed over the next several weeks here at “Eco-Compass”). While no one city has shown innovation in all seven areas, some are quite advanced in one or two. The challenge for urban planners will be to apply all of these city characteristics together, to generate a sense of hope through a combination of new technology, city design and community-based innovation, which together will create the Resilient City.
The third city model is the Distributed City (read about the first city model, the Renewable Energy City and the second city model, the Carbon Neutral City).
Cities will shift from large centralized power and water systems to small-scale and neighborhood-based systems, including expanding the notion of “green infrastructure”. The distributed use of power and water in a city can enable a city to reduce its ecological footprint as power and water can be more efficiently provided using the benefits of electronic control systems, and, particularly through water sensitive urban design, a city can improve its green character.
Most power and water systems for cities over the past 100 years have become bigger and more centralized. Now the new forms of power and water are smaller scale but often they are still fitted into cities as though they were large. The movement that tries to see how these new technologies can be fitted into cities and decentralized across grids, is called distributed power and distributed water systems.
The distributed water system approach is called Water Sensitive Urban Design and includes how to use the complete water cycle, from rain and local water sources like groundwater, to feed into the system and then to recycle grey water locally and black water regionally, to ensure that there are significant reductions in water used. This system can enable the green agenda to become central to the infrastructure management of a city as stormwater recycling can involve swales and artificial wetlands that can become important habitat in the city, grey water recycling can similarly be used to green parks and gardens, and regional black water recycling can be tied into regional ecosystems. All these systems will require ‘smart’ control systems to fit them into a city grid and also will require new skills by town planners who are used to water management being a centralized function rather than being a local planning issue.
In global cities, the traditional engineering approach to power has been that the most effective and efficient way of providing energy is through larger centralized production facilities, and extensive distribution systems that transport energy relatively long distances. This is wasteful because of line losses but also because large base load power systems cannot be turned on and off easily so there is considerable power shedding when the load does not meet the need. However renewable, low-carbon cities mostly involve a more decentralized energy production system, where production is more on a neighborhood scale and both line losses and power shedding can be avoided. Whether a wind turbine, small biomass CHP plant, or a rooftop photovoltaic system, renewable energy is produced closer to where it is consumed, and indeed often directly by those who consume it. This distributed generation offers a number of benefits including energy savings given the ability to better control the power production, lower vulnerability and greater resilience in the face of natural and human-caused disaster (including terrorist attacks). Clever integration of these small systems into a grid can be achieved with new technology control systems that balance the whole system in its demand and supply from a range of sources as they rise and fall and link it to storage, especially vehicle batteries through vehicle-to-grid or V2G technology. Small-scale energy systems are being developed to make more resilient cities in the future.
The same approach can be applied to water systems where there are now many cities that are able to demonstrate small scale local water systems that are very effective. The many developing cities that already have distributed water supplies from community bores and small scale sewage treatment, can look to a number of cases where these have been made safe and effective without being turned into expensive centralized systems. In Malang, East Java a small scale community sewage system was fitted into a squatter village to provide sanitation for 500 families.
Hanoi, the capital of Vietnam, has a major system of wastewater reuse involving vegetables, rice, as well as fish in low lying Tranh Tri district which lies to the south of the city. Produce from the reuse system provides a significant part of the diet of the city’s people (Ho, 2002). Wastewater and stormwater are discharged untreated to four small rivers which play a dual role: drainage of wastewater from the city; and wastewater supply for reuse in agriculture and aquaculture. Conventional wastewater treatment plants have been constructed but lie idle due to lack of budget for operational and maintenance costs. About one-third of the city is sewered but its pipes are directed to these small rivers. The wastewater is 75-80% domestic and 20-25% industrial.
The system for treatment has largely been developed by the district farmers and local community over the past 30 years. Before 1960 the treatment area was a sparsely populated swamp where rice was grown but with low yields and frequent flooding. Aquaculture began to develop in the early 1960s with the construction of an extensive irrigation and drainage system to facilitate rice cultivation. Farmers began to stock seed of wild fish collected from the river in rice fields as they perceived the benefits of wastewater-fed aquaculture. Following the formation of cooperatives in 1967, land use stabilized into vegetable cultivation on higher land, rice/fish cultivation on medium level land, and year-round pond fish culture on deeper land adjacent to the main irrigation and drainage canals. Wastewater-fed aquaculture became the major occupation of 6 cooperatives with easy access to wastewater and a minor occupation of 10 others out of the total of 25 district communes.
The use of waste in a food production system must always be sympathetic to public health. Traditionally wastewater has been gathered around cities and re-used only after sufficient time has elapsed for human contaminants to be naturally removed. Excess wastes were flushed into the rivers but only if the value in those wastes was mostly removed for agriculture. The use of the bioregion for waste treatment was feasible as the capacity for it to treat was not exceeded. As cities have grown, the increase in waste has far outstripped natural capacities. Cities everywhere have to find ways of treating waste as well as re-using it. Approaches that can use new technology to totally remove waste are now feasible but a distributed approach would try to use waste as much as possible in the bioregion for agricultural production as in the East Calcutta Wetlands project.
Often public health authorities have tried to ban all use of waste for agriculture which just means that water and waste are not used efficiently or ecologically. Human health is the sole focus in this approach but it is generally not sustainable to continue like this as there is not enough water and organic fertilizer to enable bioregional agriculture to proceed ecologically. The city then tends to extract water and produce food in largely unsustainable ways. Thus approaches to water and waste will require new technologies and management systems that integrate public health and environmental engineering with ecologically sound planning (Ho, 2003).
Distributed power and water needs community support. In Toronto a possible model has been developed similar to those above in developing cities, when communities began forming ‘buying-cooperatives’ in which they pooled their buying power to negotiate special reduced prices from local photovoltaic (PV) companies that had offered an incentive to buy solar PV. The first co-op was the Riverdale Initiative for Solar Energy, or RISE, when 75 residents joined together to purchase rooftop PV systems, resulting in about a 15 percent savings in their purchase cost. This then spread across the city. The Toronto (and Ontario province) example suggests the merits of combining bottom-up neighborhood approaches with top-down incentives and encouragement. This support for small-scale distributed production—offered through what are commonly referred to as Standard Offer Contracts (SOCs, often referred to as “feed-in tariffs” in Europe), has been extremely successful in Europe where they are now common. The same can be done with new technologies for water and waste such as rain water tanks and grey water recycling as part of any urban approvals.
One other model can be seen in the redevelopment of the Western Harbor in Malmö , Sweden. Here the goal was to achieve distributed power and water systems from local sources. This urban district now has 100% renewable power and an innovative storm water management system that recycles water into green courtyards and green rooftops along with the solar panels (City of Malmo, 2005). The project involves local government in the management and demonstrates that a clear plan helps to drive innovations in distributed systems.
Distributed infrastructure is beginning to be demonstrated in cities across the globe. Utilities will need to develop models with city planners of how they can do local energy and water planning with community-based approaches and local management.
What do you think? Leave us a comment.
Peter Newman is Professor of Sustainability at Curtin University in Perth, Australia. He is the co-author of Cities as Sustainable Ecosystems, Green Urbanism Down Under, and Resilient Cities: Responding to Peak Oil and Climate Change.
Peter Newman is a renowned Australian academic and planner who invented the term ‘automobile dependence’ to describe how we have created cities where we have to drive everywhere. For 30 years since he attended Stanford University during the first oil crisis, he has been warning cities about preparing for peak oil. Peter’s book with Jeff Kenworthy, Sustainability and Cities: Overcoming Automobile Dependence was launched in the White House in 1999. Newman is the Professor of Sustainability at Curtin University in Perth, Western Australia, where he is best known for his work in reviving and extending the city’s rail system. From 2001-2003, Newman directed the production of WA’s Sustainability Strategy in the Department of the Premier and Cabinet. It was the first state sustainability strategy in the world. From 2004-2005, he was a Sustainability Commissioner in Sydney, advising the government on planning issues. From 2006-2007, he was a Fulbright Senior Scholar at the University of Virginia Charlottesville and he returned there in early 2008 as Harry Porter Visiting Professor. His new book with Tim Betaley and Heather Boyer in late 2008 will be Resilient Cities: Responding to Peak Oil and Climate Change.