How many people would you guess already rely on purified recycled water as part of their drinking water supply? If you heard it’s over 30 million, in ten countries, and on track to exceed 55 million by 2050, would that shape your view?
That question is why I set out, with the Water Services Association of Australia and the WateReuse Association in the United States, to map the global extent of purified recycled water. Explaining safe drinking water often relies on complex scientific language about treatment barriers or health guidelines, which can be hard to relate to. Instead, the maps simply show where this option is already in use — a powerful story. It makes the concept tangible. The maps, online at www.water360.com.au/map/ and at water utility visitor centres, show that people in places like our own are already drinking this water safely, to meet real-world community needs.
Purified recycled water is often framed as a future solution, but in reality it is an established part of urban water systems. More than 35 cities have adopted it as part of their drinking water supply, some decades ago – with the United States leading uptake, plus Asia, Africa, Europe and Australia.
The drivers are clear. Rainfall is less reliable, population growth is increasing demand, and environmental constraints limit both extraction from traditional sources and discharge to waterways. In response, utilities are recognising that purified recycled water offers a high-quality, climate-independent supply produced close to where it is needed. Increasingly, it is seen as a core component of resilient water systems.
Purified recycled water is often framed as a future solution, but in reality it is an established part of urban water systems
At the same time, the demand landscape is shifting in new ways. The rapid growth of data centres brings a large new demand for high-quality water for cooling. The quality required often aligns closely with purified recycled water. This creates both opportunity and tension. It provides another high-value use for recycled water, supporting economic growth. But it also brings a new group of users that are relying on the same resilient supplies as communities. The result is a more complex and interconnected water future.
In this context, earlier examples of integrated water planning look rather forward-looking. Singapore’s approach, developed over twenty years ago, uses purified recycled water for industry and to augment drinking water reservoirs. What was once seen as an efficient dual-purpose strategy now appears very prescient, offering a model for how cities can balance competing demands while maintaining water security.
Despite its technical maturity, implementation can be complex. Community understanding and trust are critical. Successful projects invest in clear communication, helping people understand where their water comes from and how it is treated. One powerful insight is that water reuse already occurs in many river systems, where downstream communities rely on water that has been used, cleaned and released upstream. Recognising this can make planned reuse feel less unfamiliar and more like what it is – an extension of the natural water cycle.
Purified recycled water is also evolving. Many existing schemes use indirect approaches, adding treated water to environmental buffers such as aquifers or reservoirs. However, direct approaches are gaining traction as regulatory frameworks and technical confidence grow, particularly in the United States. This can expand the range of options available to utilities.
Looking ahead, dozens more cities are exploring purified recycled water. The direction is unmistakable. It is no longer about proving whether it works — millions of people already rely on it daily. The drive now is for quick and effective integration, so that more communities can benefit from a solution that is already hiding in plain sight.
