The UK has expertise for potable water reuse. The main issue isn’t competence, but when and how to evaluate reuse compared to desalination, water transfers and reservoir expansion.
Graham Bateman is technical director at GHD
Around the world, potable water reuse is moving from a niche to a mainstream practice. With advanced reuse expected to grow by more than 14% annually and capacity expanding faster than desalination since 2020, for regions under water stress it can no longer be considered an experiment but a planned component of long-term supply resilience.
From California to Singapore, reuse is embedded within diversified supply strategies. These programmes are not driven by novelty, but by modelling that shows rainfall-dependent sources alone cannot meet future demand. The question for the UK is not whether reuse is technically viable, but whether we are evaluating it early enough.
Emerging pressures
Population growth, tightening abstraction constraints and climate variability are already reflected in Water Resource Management Plans (WRMPs) and regional modelling. In several regions of the UK, such as the South-East, long-term supply-demand deficits are projected within current planning horizons. At the same time, environmental regulations increasingly constrain further abstraction from rivers and aquifers.
Incremental optimisation of existing infrastructure alone may not be sufficient. Diversification of supply options becomes necessary. Potable reuse should be considered within the broader resilience conversation, not as a replacement for reservoirs, transfers or demand management, but as a complementary option.
This shift is fundamental. It signifies a move away from the concept of limitless supply and towards a more circular, managed approach to water resources.
The UK is not unique
The engineering required for potable reuse is well established. Multi-barrier treatment processes, membrane systems and advanced monitoring technologies are already deployed globally in both desalination and wastewater reuse schemes, notably in California, Australia and Singapore.
Operational experience in these markets shows that reuse can be delivered safely with clear regulatory oversight and defined public health standards. The technical debate is no longer about whether reuse works, but about how it is positioned within wider water resource portfolios.
For the UK, the question is not one of engineering competence. It is about sequencing, how reuse is evaluated alongside desalination, transfers and reservoir expansion within emerging regulatory and operational frameworks. The debate is therefore one of integration within long-term planning frameworks, rather than technical capability.
Not starting from scratch
WRMPs already incorporate recycling and desalination schemes. Strategic Resource Options (SROs) are being developed to connect catchments more holistically across England and Wales. The sector is now already thinking at a national, systems-based level in a way that would have been unusual a decade ago.
The UK has the expertise, regulatory culture, and to some extent operational knowledge required to deliver potable reuse. What is missing, it could be argued, are strategic decisions on when and how it should be assessed and implemented, as well as how it should be integrated with other future water sources. Operational knowledge should be improved by learning from experience gained at reuse schemes around the world. Significant gains have been made in the planning space, but much more data is needed to further refine the models and increase confidence in planning recommendations.
Waiting for a trigger
I’m often asked whether there is a “trigger point” that will bring potable reuse onto the UK agenda: a drought, a regulatory change, or a particular supply shortfall. But that assumes the sector still has the luxury of choice. The growth of water reuse in the UK is an unavoidable outcome driven by population growth, climate change and economic activity and informed by modelling work.
The modelling already carried out across the sector, including by regional planning bodies such as Water Resources South East (WRSE), indicates that alternative sources will be required. The question is not if, but when and how they are integrated. Waiting for an acute trigger risks turning strategic planning into reactive decision-making. Delaying the discussion risks limiting options and increasing costs and complexity.
Building confidence
Whilst the engineering behind potable reuse is robust and proven, successful programmes globally have shown that technology alone is not enough. Public confidence, transparent communication, and clear terminology are essential. There are also significant survey and planning hurdles which need to be overcome in the short to medium-term.
International examples highlight the importance of demonstration facilities and early engagement, well before a potable reuse scheme becomes operational. These measures take time and can’t be rushed once pressure increases. From my perspective, the engineering aspect is the simplest; building shared understanding and confidence demands foresight and planning.
Keeping options open
Potable reuse may not be suitable everywhere. It is not a silver bullet, and it should not be regarded as such. However, it should not be dismissed from serious consideration simply because it has historically been outside the UK’s comfort zone.
For engineers, planners, legislators and investors, the priority should be to keep future options open. Potable reuse does not need to be adopted everywhere, but it should be evaluated alongside desalination, transfers and reservoir expansion before pressure turns long-term planning into short-term reaction. Longer-term data-led planning scenarios will provide the flexible and rigorous approach to support reuse implementation decisions across the UK water industry.
- Graham Bateman is technical director at GHD
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