Edges to Urban Growth

Ebenezer Howard didn’t start the craze, he only picked up where the ancient Greek concept of natural limits to growth lay abandoned in the ruins of the agora. In the 2000 years since the explosive growth of Athens’ civilization, the normal moderators of population growth – plague, fire, food – ensured that population numbers remained in balance. But by the early twentieth century, the industrial revolution, plus the evolution of the medical and agricultural fields resulted in intense development pressures from overcrowded cities, which could only build up… or out.

The ancient Greek city could not be too far removed from the rural areas and Dionysian pleasures. Aristotle’s Lesson of Controlled Growth, with established natural limits. “What we have said concerning a city… is sufficient in itself to furnish what will make the inhabitants happy; for which purpose it must be able to supply them with all the necessaries of life; for it is the having these in plenty, without any want, which makes them content.”

Howard designed the Garden City for an ideal population of 32,000 people, with greenbelts encircling new towns, spaced about three to five miles apart, based on the distance between rail stations. The extension of rail lines in the 1840’s resulted in deserted stations offering the promise of things to come. Nearby landowners saw the benefits that the railway line would bring, by turning their farmlands into prime lots for development. Howard’s Garden Cities were built at Letchworth and Welwyn, England, with concentric rings of functions, preserving agricultural lands to prevent one town from encroaching on another.

In Jane Jacobs’ eyes, however, Ebenezer Howard “not only hated the wrongs and mistakes of the city, he hated the city…. His prescription for saving the people was to do the city in.” Jacobs took great exception to the series of “decontaminated sortings” that were the result of many of the Garden City recommendations, preferring instead the messy and unsorted life within the city – the small blocks and multiple paths of travel, the mixed uses, the generators of diversity that distinguish one neighborhood from another. In this, she was aligned in direct opposition to Lewis Mumford, who wrote, “The law of urban growth, as dictated by the capitalist economy, meant the inexorable wiping out of all the natural features that delight and fortify the human soul in its daily rounds.” Now, Jacobs was not suggesting wiping out greenspace, nor was Mumford in favor of the creep of grey infrastructure across the plains and prairies of open space. But it is true that at the first sign of a boom, skeleton streets are extended and infrastructure is laid, and with their existence arrives a self-fulfilling result, with the first scattered houses and convenience stores punctuating the edges of the asphalt ribbon.

Communal edges once provided buffers of non-developed land between cities. These green spaces acted as rings around the towns and cities, providing nature’s resources for the residents’ benefit. With the growth of mega-regions, the ratios have reversed; the stands of forest and sensitive lands that were once ignored in favor of more desirable (and more profitable) development are now converted into housing estates, manufacturing, and mini-storage. In response, cities from Minneapolis to Miami are beginning to define rigorous urban growth boundaries, instituting increasing fees and higher taxes for new “edge city” developments, or limiting water runoff, sewer treatment, and traffic to “pre-development” levels in an effort to control the uncontrolled expansion of community edges.

Regional plans encouraged by the Charter for New Urbanism recommend geographic boundaries be respected. “The metropolis has a necessary and fragile relationship to its agrarian hinterland and natural landscapes. The relationship is environmental, economic, and cultural. Farmland and nature are as important to the metropolis as the garden is to the house. Development patterns should not blur or eradicate the edges of the metropolis.”

But often, the edges become wastelands. Michel Foucault wrote, “in the margins of the community, at the gates of cities, there stretched wastelands which sickness had ceased to haunt but had left sterile and uninhabitable.” These edges are the blight-prone, dead-end, single use barriers that worried Jane Jacobs in “The Curse of the Border Vacuums”.

Community edges may save us from our own inventions, the chemical, biological, and mineral hazards we have unleashed. Creating green zones, buffers of wild lands between industry and inhabitation and dividing mega-regions into identifiable fragments, will mitigate the proximate effects of population expansion. In order to improve resilience and self-sufficiency, Camillo Sitte’s “sanitary and decorative greenery” that girdles, crosses, or encircles old and new communities may help us to process waste, build oxygen, sequester carbon, produce food, compost and recycle solid waste, and many more requirements, for cities to become true, circulatory ecosystems.