Increasing urbanization places cities at the forefront of achieving global sustainability. For cities to become more sustainable, however, the infrastructure on which they rely must also become more productive, efficient and resilient. Unfortunately the current paradigm of urban infrastructure development is fragmented in approach lacking a systems perspective. Urban infrastructure systems are analogous to ecological systems because they are interconnected, complex and adaptive components that exchange material, information and energy among themselves and to and from the environment, and exhibit characteristic scaling properties that can be expressed by Zipf's Law. Analyzing them together as a whole, as one would do for an ecological system, provides a better understanding about their dynamics and interactions, and enables system-level optimization. The adoption of this "infrastructure ecology" approach will result in urban (re)development that requires lower investment of financial and natural resources to build and maintain, is more sustainable (e.g. uses less materials and energy and generates less waste) and resilient, and enables a greater and more equitable opportunities for the creation of wealth and comfort. The 12 guiding principles of infrastructure ecology will provide a set of goals for urban planners, engineers and other decision-makers in an urban system for urban (re)development. Highlights• Infrastructure ecology, a novel paradigm for urban infrastructure development is presented.• Urban infrastructure systems function analogous to natural ecological systems.• Interdependence between infrastructure sectors are identified and assessed.• Infrastructural symbiosis reorganizes the flows within for system-level optimization.• 12 guiding principles of infrastructure ecology are presented for decision makers.

The destabilization of earth’s climate—manifest today in rising sea levels, more frequent droughts, deluges, and rising temperatures—demands expansive thinking in our infrastructural investments. Such volatility imperils coastal and riverine populations, degrades agriculture, and fosters water insecurity. We require innovative, multidimensional solutions to these public works challenges. Infrastructural ecology is a planning paradigm that emulates the closed-loop, sharing logic of natural ecosystems. It suggests that features of our power, water, sanitation, transport, and food systems may be strategically combined, collocated, or otherwise linked for mutual benefit. Such interconnected systems then can cascade (pass along) waste energy or water and nutrients for another’s reuse, arrangements that can reduce pollution and greenhouse gas emissions, while lowering demand for new resource inputs. Innovative examples from both industrialized as well as developing nations illustrate the efficacy of these strategies. The exemplary projects described here include smart coastal solutions, water-wise innovations, and coping strategies for warming cities.