How do we prevent today's water crisis becoming tomorrow's catastrophe?

“Water, water everywhere, nor any drop to drink.” In these lines, Samuel Taylor Coleridge made a prescient point: while seawater is plentiful, people can survive only with fresh water. This surprisingly scarce resource is the lynchpin sustaining human lives and healthy ecosystems across our rich biosphere: the most vital resource for life on Earth as we know it.

Yet despite its vital importance to humanity, the global water crisis has failed to take priority in the public consciousness. This year, for the first time, there is cause for optimism. In an unprecedented moment for the global water debate, His Holiness Pope Francis inspired a global conversation by opening World Water Day.

As Pope Francis noted in his address to a Pontifical conference on the human right to water: “[Our concerns] are basic and pressing. Basic, because where there is water there is life, making it possible for societies to arise and advance. Pressing, because our common home needs to be protected.”

Yet, water and the freshwater ecosystems that sustain it are under-valued, poorly managed and increasingly depleted.

A common paradox is that, whether a crisis of dearth or abundance, there’s a water problem everywhere on Earth. Half of the world’s largest cities experience water scarcity. Two-thirds of humanity face seasonal or annual water stress. And with climate change, growing populations, and agricultural demands, the global water crisis will only worsen. If current trends continue, demand is expected to outstrip supply by 40% within 15 years.

It’s clear we need to change. It is time to embrace a new paradigm for solving our growing crisis: valuing water wisely, and managing it using principles of sustainability, inclusion and resilience.

One of the key global initiatives that is already working on this is the High Level Panel on Water (HLPW), 11 heads of state and one special advisor, supported by the United Nations and the World Bank. These leaders are championing a more comprehensive, inclusive and collaborative way of managing water resources, and improving water and sanitation related services. Last September, the HLPW called for a fundamental shift in the way the world looks at water and issued an Action Plan for a new approach to water management that will help the world to achieve the 2030 Agenda for Sustainable Development, including the 17 Sustainable Development Goals.

A core underpinning of this approach is valuing water. Valuing the social, environmental and economic benefits of water is a pre-requisite to managing it efficiently, resolving tradeoffs among increasing demands and providing incentives to businesses, households and farmers to manage water resources more judiciously.

Today, a number of key global leaders representing government, civil society, multilateral organizations, media and the private sector will also convene for a Watershed dialogue hosted by the Vatican. Its over-arching theme - Replenishing Water Values for a Thirsty World – is focused both on the critical nexus of water, and its environmental, social and economic importance and the imperative to act now.

With appropriate valuation and assessment of our freshwater ecosystems and water resources, we will better manage water and we can readily transition to building Freshwater Resilience – the ability of freshwater ecosystems to thrive under change and to continue to deliver their essential services to humanity. Achieving Freshwater Resilience means enabling natural and human systems to respond and adapt to shocks and stresses and to transform to new realities of global change. Building freshwater resilience is imperative to maintaining the resilience of human economies and societies so fundamentally dependent on water.

Few places demonstrate the need for Freshwater Resilience better than Mexico City. Once the center of the Aztec Empire, known as “the Venice of the New World,” Mexico City is now collapsing on itself. Despite having more rainfall than London, it suffers from water shortages more akin to a desert. Despite the huge efforts made to extract more water from the local aquifer and inter-basin transfers the water availability per capita in the Mexico City Metropolitan Area (MCMA) remains the lowest in the country: less than 30% of the approximately 20 million inhabitants of the MCMA receive continuous 24-hour water service.

Mexico City, which is part of the 100 Resilient Cities network and has a Chief Resilience Officer, is collaborating with the federal government to address water challenges together. Following principles of Freshwater Resilience, working alongside the World Bank, The Rockefeller Foundation and other partners, together they are taking a comprehensive approach to water supply planning that is fundamentally new. It includes an analysis of diverse demand and supply side options, and assesses their relative contribution to the resilience of the water systems of Mexico City and surrounding watersheds. The goal is to move away from ‘business as usual’ approaches and create systems that perform better in the face of shocks, stress and uncertainty.

So, how does this work in practice? There are a number of options on the table, from traditional measures of improving hard infrastructure and reducing leaks in distribution systems, to innovative measures of restoring watersheds, enhancing natural infrastructure for storm water management and groundwater recharge, and improving water system monitoring .

Mexico City is just one microcosm for how we believe partners can address water challenges of the 21st Century. In a time of great change, steeped with uncertainty and potential for nonlinear shifts, Freshwater Resilience is a powerful and coherent framework for the kind of transformation we need for humanity to thrive under the dramatic changes that are our new normal. Without a new approach, today’s water crisis will be tomorrow’s catastrophe.