The shape, for example, of the future city is one of the single most important dimensions of the sustainablecity and, somewhat perversely, the shape of that future city must be more like the shape of the older city, the city prior to the advent of private mobility in the form of the car at a scale that allowed us to flout the rules of how people attach themselves to the land in naturally-occurring spatial patterns.

In our southern African context, we must also be aware of the fact that the most challenging aspect of the future city is that it will be a MegaCity, remembering that the MegaCity is not simply a very large conurbation but rather an urban phenomenon that is uniquely influenced by the geo-political landscape of emerging, underdeveloped regions. North America, for example, has many very big cities, in the order of 8 to 12 million people, in relatively close proximity to one another which collectively service relatively small hinterlands of generally extensive,
well-distributed wealth.

Western Europe, too, shows a similar pattern. Central and South America, however, which are far less wealthy regions and in which wealth is extremely unevenly distributed, show a very different pattern of settlement and Sao Paulo (probably at present the most well progressed examples of the megacity and approaching an urban population of 30 million) and Mexico City have been early indicators of the megacity phenomenon. We see the same thing in South East Asia where cities such as Jakarta, Manila, Mumbai and Kolkata grow to a massive scale in servicing vast hinterlands of need where wealth is not only limited but very disproportionately distributed. Africa already clearly shows how megacities are the product of massive shifts from grinding rural poverty to centres of perceived opportunity: Cairo, Lagos, Gauteng and, to a lesser extent, Nairobi. This is not to say that other smaller cities and towns will disappear or become less important: it does mean, however, that they will, in turn, be influenced increasingly by their spatial and market relationships with these megacities.

Referring to the Gauteng City Region (GCR), the Gauteng Spatial Development Framework (GSDF) reflects a briefing for the MegaCity: it is a framework that must be robust enough to cope with growing to roughly 30 million people over the next 40 or so years yet flexible enough to do so at rates that are erratic and variable and from areas and places that are unpredictable. Interestingly, with its present population of about 12.5 million people (with only about 400 000 of these being, technically, "rural" by virtue of Gauteng being such a small province with by far the largest economy and market) the GCR only takes up about 27% of the provincial land area. And yet, even at this relatively efficient level, it is populated in a very 'baggy' way with only about 2200 people, on average, per km².

Compare this, for example, with London at about 5500 people per km² (and not even considering the urban intensities of places like Mumbai at roughly 11000 people per km²) and we realize that the GCR can be greatly intensified simply by consolidating within what is already spatially intact and serviced with particularly good levels of infrastructure and where further investment can be made to be even more efficiently directed. The GSDF, in fact, finds that, far from this figure of some 30 million people being a terrifying prospect, it can indeed be accommodated relatively easily without having to extend our urban footprint beyond about 30% of the provincial area.

This means that the surrounding 70% of land remains to nurture the larger dimensions of ecological and bio-diversity attendant on the MegaCity and work symbiotically with the city as the “urban bread-basket”. In its extreme beauty and complex ecological profile, this hinterland will also remain to help restore and protect natural assets such as our aquifers (with Gauteng projected to become wetter under a scenario of global warming) and making a vital contribution to the recreational needs of a 30 million strong population living within the intensity of urban concentration.

In the light of the vast disparities in wealth and resource distribution that characterise the megacity, it is vital that sustainability be understood in its social, political, economic, cultural and ecological dimensions. The GCR therefore aims to develop as a significant emerging MegaCity based on the following principles of sustainability:

• Significantly reducing reliance on private mobility in favour of safe, reliable and affordable public transport and non-motorised transport (particularly walking and cycling);
• Significantly reducing present rates of non-renewable energy usage;
• Reducing the rates of energy expended in the manufacture of goods, the delivery of these goods to market and the import of goods;
• Integrating open space systems into the city region and providing sustainable eco-systems, urban agriculture and quality of life as a fundamental of the province’s development patterns;
• Promoting a democratic urban order in terms of access to opportunity for all;
• Achieving an integrated urban and rural economy and prioritising food supply to the urban market from its immediate hinterland.

In achieving these objectives, the GCR will become more nationally and globally competitive and grow a sustainable urban economy that supports quality of life and inclusion for all its citizens.

What are the implications of this for the urban structure of the megacity? The GCR seeks to focus on the urban structure of the city rather than in spuriously assigning populations to various parts of the urban system as is quite common in planning.

Instead, the urban fundamentals must be such that populations choose to locate where the system offers most opportunity (in all socio-economic, cultural and perceived amenity aspects) and this means that the urban structure must be characterised as follows:

• A robust urban structure to accommodate growth in non-specific ways and at variable rates;
• A flexible structure that accepts adaptations as times, circumstances and technologies change;
• Normality (as opposed to the spatial dislocation and dysfunction of the apartheid city)as a basis for the city’s structure, logic and performance;
• The re-incorporation of the public domain as a focal aspect of the city and the enablement of economic opportunity;
• Public rather than private mobility will provide the basic logic of urban structure
• The form, shape and patterning of the urban system is to be based on the integrated principles of spatial compactness and urban complexity;
• The urban systems planning and management is to be infrastructurally led.

Far from being terrified by the caricatures we draw of our urban futures, cities are our single greatest cause for optimism in meeting the challenges of sustainability. They are, indeed, a fundamental part of the solution. But we cannot get to this by allowing the city to be formed on a ‘business as usual’ basis where expediency moves always to the simplest, unchallenging car-based lowest denominator of urban sprawl and gated villages. There has to be fundamental change in re-conceptualising the city and there has to be the political will to make the capital reinvestments into existing infrastructure, most notably into our very extensive passenger rail systems.

Source: GAPP Architects and Urban Designers