Sustainable Urban Systems: Managing the Urban Multiplex and its Hydrologic Challenges

Modern cities are challenged by climate change, growing populations, shrinking and polluted natural systems, and rapidly ageing and outdated infrastructure. These challenges manifest themselves in a wide range of problems from flash flooding to public health issues due to lack of clean water for drinking and recreation. Such events expose the fault lines of urban infrastructure management. Perhaps more importantly, they also reveal the complex and interconnected nature of engineered, natural and social systems that form the fabric of modern cities.

These systems can be conceptualized as a network of networks, or Urban Multiplex, that includes surface water and groundwater, sewerage and drinking water systems, inland navigation and dams, the power grid and the transportation network, all intertwined with the socioeconomic and public health sectors. Yet, traditional urban infrastructure management approaches deconstruct this complex system along specific business and political lines, and manage its components separately, often as if they were not related. The traditional modus operandi remains in place because urban infrastructure development and management is overseen by a multitude of organizations and facilities that operate largely independently from one another to meet their own requirements, and often have conflicting interests. The result is cascading failures across the Urban Multiplex, with catastrophic impacts on human and environmental health.

Solving these problems requires a concerted, multi- and interdisciplinary effort that systematically addresses the interconnections between subsystems of the Urban Multiplex, and identifies potential pathways for cascading catastrophic failures. We present a synthesis of emergent concepts and technologies for the Urban Multiplex and its hydrologic challenges developed by a working group of experts from utilities, private industry, academia, non-profits, and federal transportation, environmental and public health authorities.