Cities as Hydro-Geologic Terrain: Design Research to Transform Urban Surfaces

Imperviousness is a significant design problem for the future of cities: we must reduce it, redesign it, transform it. This paper argues to insert hydro-terrain thinking to the paved surfaces of cities, instantiating the concept of “rain terrain” that links hydrologic performance across scales, from the raindrop to the region. The City of Chicago is the case study where high concentrations of pavement drain stormwater from the city-resulting in flooding, overflowing and polluting-from the Great Lakes to the Gulf of Mexico. I first share research on the glaciated history of the region, to reveal sandy soil types located in the urban area. I then correlate imperviousness, permeable soils and flooding prevalence to identify a pattern of site opportunity areas in the city. I also propose design practices-through disruptions, interventions and reconfigurations of urban surface-to tap paved-over soils as the basis for a landscape-based urban stormwater approach. In doing so, this paper aims to present a vision for urban transformation, based on specific technical design opportunities within landscape-as-infrastructure.