Urban infrastructure is not a tree: Integrating and decentralizing urban infrastructure systems

In his original 1965 article, Christopher Alexander argued that master planned cities ultimately failed because the designs elaborated followed a tree structure as opposed to a more desirable semilattice structure present in organic cities. In this article, I argue that a similar claim can be made with urban infrastructure systems planning. As cities expanded and became increasingly complex in the 20th century, the responsibility to plan and design urban infrastructure was distributed to separate agencies that seldom communicate and coordinate with one another. In the global context to make cities more sustainable and resilient, a better integration of infrastructure systems may hold much potential. After recalling Alexander’s main concepts, I examine how current infrastructure systems are naturally interdependent. I then discuss the role of integration, by notably proposing an integration-decentralization matrix, with four quadrants, illustrated by using practical examples. The quadrants are current paradigm, siloed distribution, localized integration, and integrated decentralization. Overall, a better integration of urban infrastructure can offer significant benefits to a city, and it may be time to seriously revisit our current urban infrastructure systems planning practice.