The urbanization of an idea: Imagining nature through urban growth boundary policy in Portland, Oregon

A concept of a specifically "urban imaginary of nature" is developed through a dialectical (re)reading of Georg Simmel's and Louis Wirth's seminal texts on the nature of urbanism. We then examine how this urban imaginary is mobilized through the politics of nature in metropolitan Portland, Oregon. We demonstrate that the logic of Oregon's "Urban Growth Boundary" land-use policy promises the retrieval and spatial demarcation of a fading "nature" threatened by urbanization itself. We then examine how Portland's metropolitan planning agency ("Metro") imagines ways in which the urban growth boundary can reconcile and spatially delimit an "invisible line" where the urban ends and nature begins. These policies set the conditions through which Portland can market itself as the "green city." We conclude by arguing for a more radical and denaturalized political imaginary tha takes into account the socioecological constitution of the urban "metabolism" itself.