Resilient Urban Water Systems

How can we best use principles drawn from natural ecosystems – in tandem with those from engineering, design and institutional frameworks – to develop and operate resilient water systems?  How can we provide reliable, productive, and equitable water systems that minimize hazard and waste in the most densely populated habitats of the planet (21stcentury cities) and their contributing watersheds?

Background:  Urban water resources infrastructure, often quite costly, massive and over-designed, have been developed over the 20th century to provide sufficient quantity and quality of freshwater supply, sanitary treatment and disposal, and stormwater drainage.  These systems are operationally centralized and highly capitalized, and designed to operate for multiple decades with the goals of diverting or storing surface or groundwater sources to overcome drought shortfalls, treating supply and effluent to protect human and environmental health, and draining stormwater to reduce urban flooding.  Infrastructure typically extends beyond the urban service area, and this has potential impacts and conflict with both upstream and downstream communities and environments through diversion of upstream freshwater, and sanitary and stormwater drainage downstream. 

Design and maintenance challenges include those that are regulatory, technical, political and financial in nature, and climate change.  In rapidly urbanizing developing countries the lack of financial and institutional resources for the high capitalization to implement and operate new infrastructure, and the lack of sufficient water quantity and quality are major health, economic and equity challenges.  There is increasing recognition and interest in improving the resilience of water resource systems in diverse socio-cultural contexts by adapting coupled green and grey infrastructure and technologies to protect source waters, treat and recycle wastewater and stormwater.   

This working group will investigate the socio-environmental conditions and development potential and constraints of green and grey urban water resources that will achieve resilient, equitable solutions to urban water management.  We will:

  1. Inventory a range of cities in terms of their current and potential future transition between grey and green infrastructure, centralized/decentralized systems, importing vs recycling approaches to resilient water systems. Case studies, will span an array of contemporary and potential future conditions, and will include:
    • Advanced cities with centralized systems, shifting reliance on imported to recycled water, and strong financial/institutional capacity (e.g. Singapore)
    • Cities that have not implemented centralized infrastructure and may “leapfrog” traditional grey to develop more green oriented infrastructure (e.g. Kampala) ,
    • Older US cities that are retrofitting and shifting grey to grey/green infrastructure solutions to achieve multiple sustainability goals (NYC, Washington, Baltimore)
  1. Identify the organizational principles that promote water resilience in naturally evolving ecosystems, and translate these into new urban design and engineering paradigms adapted to the range of urban areas investigated above.