Ed Wall – Watershed urbanism
This paper outlines the potential that the watershed, as a landscape area defined by the finite resource of water, has for providing such a framework for new urban settlements. In response to increasing water shortages, are there more creative solutions available than have been expressed before? The cost of moving water across the landscape will also be addressed through several contrasting examples where cities and regions are challenged through insufficient water availability. Finally, I discuss the practice of ecological footprint calculations; a method which links a measure of global hectares to human activities of consumption and waste.
The earth has always relied on a level of flux for regeneration and renewal of the environment. However, until the Industrial Revolution, the earths’ ecosystems remained in balance, with no single species having the potential to affect the environment at a global scale. Beginning with the burning of fossil fuels within an industrialised world, the effect that humankind has had on the environment has accelerated and become more evident. It is only since the American scientist, Charles David Keeling, began researching increasing carbon dioxide levels in the environment 50 years ago that this effect has been recognised. A recent article describes how Keeling recognised the effect that industrialised urban areas were having at both regional and global scales.
Increasing emphasis has been placed on ecological footprints and resource-flow analysis to understand the quantities of resources used and the amount of waste produced by individual settlements. This research has highlighted the disproportionate amount of resources used by cities and the network of global flows from across wider geographic regions. London alone has been calculated to have an ecological footprint twice the size of the rest of the UK, with 81% of its food being imported from overseas . The City Limits report stated that “a 35% reduction of [CO2] production by 2020 and an 80% reduction by 2050” would be required if London was to achieve a predicted ”earthshare” in 2050, or 1.44 gha (global hectares) per capita.
Settlements and resources
Mercantile cities like London have always relied on their territories to supply them with their resources. Without a supply of food, water, and building materials imported from the hinterland, city life would not have survived and flourished. For this reason, the blockading of cities has proved to be a highly effective method of warfare, as it separates the city from its territories and starves the population of food, water, and other essential resources. Cities have also evolved greatly in the last century, first through industrialisation and later through processes of globalisation, and they have achieved greater efficiency in the sourcing, processing, and supply of their resources. Cities have extended their territories beyond the land that they own, or even govern, becoming increasingly dependent on national and international flows of trade. These increasingly efficient systems generate profits by supplying large global populations with everything from baby carrots to microelectronics, always trying to reduce costs without overloading the resource-supply systems. The potential of collapse is, however, increasingly evident in societies that are so dependent on imported resources. The global economic decline of the 1970’s was a direct result of this dependency, as changing availability of crude oil for a growing car and oil reliant North American society sent prices soaring. The sustainability of cities clearly relies on the long-term management and control of its resources, with water and food supplies being among the most important.
Settlements and environments
Human settlements have always considered aspects of the environment in which they are located. For thousands of years historic market towns have developed from the crossing of trade routes, spa towns have emerged at natural springs, and other settlements have clustered around ports, bridges, hilltops, and estuaries. Since the twentieth century urban planners have been accused of undermining the relationship between cities and their environment as technological advances in materials, transportation, and construction have allowed newly built forms to engineer the landscape. However, centuries ago, the Egyptians ignored the natural landscape to transport water hundreds of miles with innovative aqueducts, and the Romans also built linear military roads across the territories of Europe in defiance of existing landform and geographic features. Since then, globalisation of markets, transportation, and knowledge has intensified this disconnection with the landscape, where contemporary cuisine now reveals only the slightest relationships between farming and food consumption and architecture responds to a global aesthetic.
Signs of a resistance to this trend have been emerging in both contemporary and established fields. One direction comes from the environmental sustainability movement, with significant examples in the zero carbon developments by Bill Dunster. In the first of these developments, to reduce the energy in transporting building materials, a design code was established that required materials to be sourced from within a 35-mile radius. This self-imposed restriction re-established a relationship between the materiality of the architecture and the local available resources. In Italy, the slow-food movement that came to prominence in the early 1990’s has inspired both an appreciation of local food products and has led to wider ideas such as the concept of Slowtopia. The trend-forecasting agency, The Future Laboratory, has used the term Slowtopia to describe an emergence of slow travel, food, and culture based on the quality of the experience. Local, they predict, is expected to define quality, while energy consumption and high food miles embody unnecessary exuberance.
Is there a potential for these ideas to be developed in the discipline of urban planning? Could the examples of ZEDFactory be applied to a whole city or region where, rather than using an abstract radius of 35 miles, an environmental measure could direct the capacity of the landscape?
Settlements and water
Civilizations and their settlements have historically benefited from a close relationship with water. From ancient Mesopotamia to contemporary metropolises such as Rotterdam, New York, Tokyo, and Shanghai, the proximity to water has been essential. From trade, defence, sanitation and drinking to religious and spiritual ceremonies, water in its many forms has been at the centre of generations of human settlements. As these settlements have grown into large cities, the water has impacted both demographic changes and physical growth. Manhattan’s response to being constrained by its shoreline was to build into the sky. Across the Atlantic, huge dams in the Welsh valleys were financed by the distant city of Liverpool in order to supply their growing mercantile population with drinking water. In California, many rivers have been diverted and culverted to supply the population of Los Angeles; these engineering events are brilliantly narrated in Roman Polanski’s film, Chinatown, where murky activities of diverted water supplies, urban development, and suspicious suicides dominate.
Transporting potable water for these expanding towns has been expensive. Diverted rivers, aqueducts, canals, pumping stations, and often entire tankers of drinking water have been deployed to prevent water shortages and stagnation of economic growth. The planning and development website, Planetizen, reports that the doubling of the Arizona population in the last 25 years is straining the finite resources of the state: “Unchecked development threatens to overwhelm rural Arizona’s limited water resources, leaving entire communities vulnerable to shortages and rivers at risk of running dry.” In Australia, some cities are proposing shipping water from New Zealand and Tasmania. A company chaired by former Prime Minister Bob Hawke has been consulting the Tasmanian government about the feasibility of buying fresh water and transporting it to Brisbane, Sydney, and Melbourne in specially designed aquatankers. While this method is claimed to be cheaper in the short term than building new dams and desalination plants, the long term sustainability of this is unclear. The precarious nature of importing large amounts of essential resources was clearly underscored when, in September 2000, the blockading of oil refineries in the UK brought the country to the verge of a national food crisis. Should other methodologies not be explored? Is there a more robust approach that can withstand changes in global politics, markets, and the environment? Can our resources influence our urban planning in a more proactive manner?
Water and the watershed
One approach could be to use the watershed as an environmental measure that directs the planning of new settlements. Watersheds, drainage basins, or water divides are some of the alternative approaches for describing a land area in which all rainwater that falls within it reaches the same destination of rivers and estuaries. The watershed is one of several environmental systems that geographers use to understand the relationship between the earth and water resources, and watersheds are unique in that they bring together a measurable territory with a quantifiable and renewable resource. Aquifers, water tables, and watersheds can be measured for their size, their flows, their capacity for holding water, and their capacity for supporting flora and fauna. Because a watershed contains a quantifiable amount of renewable water and is clearly expressed on the earth’s surface in the form of changing topography, the watershed holds great potential as an urban-planning tool.
Recent European and UK directives have recognised the impact that planning and land use has on the quality and quantity of water within our river basins. In the UK, the Water Framework Directive, which came into force in December 2000, looks to reduce the negative impact of planned and unplanned human activity on the resources within river basin areas. However, rather than just mitigating the effect of external factors on the watershed, there is potential to propose a process that increases the influence of the watershed on planning.
It is with this premise that alternative urban-planning techniques could be developed to ensure the sustainable supply of resources to both cities and their surrounding territories. If the basic needs of a population are considered as water, food, and shelter, then planning new cities around locally sourcing these essentials could achieve a greater balance of resources for our urban regions. The amount of human activity that can be sustained by food and water available from within a particular watershed can be calculated through understanding the agricultural capacity of the watershed and the available water supply within the watershed. By combining this with ecological footprint data, resource flow analysis, and local geographic information such as the capacity of the land for human settlement, an optimum population and density can be determined for the watershed. By following this methodology, urban planners could gauge the maximum number of people that a specific watershed territory might sustain with its own resources and could therefore provide guidance on the size of new cities, towns, and villages. With each new layer or application of this approach, urban and regional planners have the potential to understand how much activity could be supported by local water, food, timber, minerals, open space, and other resources within the watershed territory. Like ecological footprint calculations, a strong understanding of the sustainability of a region could be determined; however, by using the watershed, rather than the intangible area of a global hectare, a greater accountability by each administrative region could be achieved.
This method demonstrates a potential for understanding the landscape in measurable territories that can be analysed with regard to their self-sufficiency. The reason that water and food are used as the guiding principles is because of the importance of these resources for human survival, because of the energy-intensive methods for transportation of water and food across the landscape, and because increasingly the delicate balance in which many cities currently find themselves in relation to their water and food resources is critical. The shortages of water that have occurred in recent decades will only heighten as global climate change pushes temperatures higher. In Australia, the establishment of a Minister for Climate Change and Water underscores the connection that many societies are making between climate change and their essential resources. The sourcing of local food and materials will also become increasingly important as fuel prices rise.
Controlling population growth within land areas appears extreme; however, it is not unprecedented. Both recent and ancient examples of population control have come about through attempts to balance available resources within a climate of growing demand. While infanticide, as practiced by some ancient Greek cities, may not be widely acceptable, voluntary birth control is still promoted in most countries. The extent of immigration control may also change through successive administrations, although it is evident at national border crossings that some travelers may be restricted from entering. And even urban planning itself implies a population control in the extent of development control that it dictates, resulting in certain sizes of settlements with certain populations.
There is potential for measuring and guiding the use of other commodities in this way. The management of waste, for example, could be seen as a responsibility for the landscape of the watershed rather than being shipped to remote locations. The scandals that have emerged as waste has been transported across the globe are due only in part to NIMBY (Not In My Back Yard) attitudes and more to the lack of responsibility that we have historically taken for our waste. The LGA (Local Government Association) estimate that landfill sites in the UK will be at capacity within the next decade and suggest that alternative proposals are required.
The sourcing of local materials and resources from within our watershed areas could bring back local distinctiveness to our built environments. While shopping locally can “discourage car use, offer a more personal service and support the local community,” using local materials for building our cities could reduce the transportation impact, create a new local aesthetic, inspire new economies, and generate local skills. While the argument for stimulating local economies contradicts many of the benefits gained by global corporations, the argument for distinctiveness in the design and composition of our cities is critical. The exporting of granite from China is clearly not sustainable for countries that already have available stone resources. The use of local stone in Montana and Portuguese granite in Portugal would recreate a local identity such as that earned by the Scottish city of Aberdeen, when it was nicknamed the Granite City for its abundance of granite buildings.
The watershed could even redefine national and political boundaries. In several countries, watershed districts, catchment boards, and river basin districts have been created to manage issues relating to watershed resources. At present, these exist as conservation and preservation bodies that promote the protection of the water in the watershed; however, there is clearly potential to develop these into more proactive entities that use their understanding of existing resources to provide greater planning guidance. Past legal feuds over water are expected to pale in comparison to future conflicts over water resources. Therefore, might a proactive planning approach that manages the growth of settlements in relation to sustainable access to resources avert these so-called water wars?
This paper outlines a simple concept that combines the flows of available resources within a definable space in order to understand the maximum settlement size that a watershed can sustain. If developed and calculated to include all resources needed for survival on the city, the watershed could become the equivalent of the city’s ecological footprint but would use a tangible spatial type, resources, and accountability. Within this framework, movement of resources and people could still occur between watersheds and countries, although only with the knowledge that each global watershed was in balance. In the future, might London be defined by the watershed of the Thames Valley rather than the ring-road of the M25 motorway? Or could New York State be defined by the extent of the Hudson Valley and recognize its reliance on and responsibility to other states? Few landscape typologies are directly associated with an essential resource and for this reason the watershed holds an interesting potential for understanding the relationship between human activity and a multi-scaled landscape.
 Marco D’Eramo. The Pig and the Skyscraper: Chicago: A History of Our Future (New York, NY: Verso, 2003)
 Jared Diamond. Collapse (London, UK: Penguin Books Ltd, 2006)
 Martin Raymond. “Autumn 2007 Trend Dossier” The Future Laboratory (2007) 23-25
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