Do we know what the future demand for water will be? My answer in February 2020 would have been a cautious “yes”. Five years on, following the impacts of COVID-19 lockdowns and the subsequent “new normal”, a record-breaking heatwave and a Cost-of-Living Crisis, I feel much less confident.
We have learnt more about how these shock events have affected water use, but as we have learnt more, our awareness of what we don’t know has grown. Events of the past five years have revealed unknown unknowns that could, paradoxically, perpetuate more uncertainty into the future. We have also seen the tangible effects of climate change in the record-breaking temperatures of 2022 and the prolonged dry summer of 2018. Future climate driven demand events are both inevitable and unpredictable.
Looking to the future, the twin goals of growth and net zero depend on our ability to cut our demand for water over the next ten years – that is how long it will take for planned new reservoirs and water transfer schemes to start coming on stream (pun intended). In that time, we are expecting new water demands – to cool data centres and produce clean hydrogen energy – to escalate, but only in specific locations. At the same time a ten percent increase in the population (via net migration) and ambitious housing growth targets will drive up household demand for water. On top of this it’s impossible to predict the next ‘black swan’ event in a world full of turmoil.
It is clear that the future of water demand is more uncertain than ever, and if we want to appreciate and address this uncertainty, our forecasting methods must evolve to create a more resilient path forward. There are five key areas I believe would address this challenge:
1. Non-household demand forecasting must become more tailored to different business sectors and sub-regional specifics. We will need to talk more to people in emerging sectors like data centres and hydrogen power to understand their water needs better.
2. If we are to rely on explanatory factors to predict either household or non-household water use, they need to be more precise, even if this is only possible for the next five to ten years. This will mean better water demand forecasts in growth centres like Cambridge and wherever the proposed new towns are delivered.
3. Peak demand events define the resilience of our system and so how we characterise dry years and critical drought events needs to improve. Plus, we need to develop more effective methods for evaluating the future impacts of climate change on peak demand.
4. A different and uncertain future means we will need to reconsider methods that rely on historical analysis to predict future trends. Forecasting will need to focus more on approaches that consider a range of different futures (such as scenario-based approaches and expert elicitation) to capture the huge uncertainty in water demand planning after 2035.
5. It’s critical that we reduce demand over the next ten years and adjust our measures if we’re failing to deliver. This means that forecasts should be reviewed and adjusted on a regular basis, as new data becomes available, to enable adaptive pathways to be pursued. To make this happen, we need to develop effective and agile processes and tools to bring greater value to annual reviews.
Ultimately, collaboration and an agile approach are key as we navigate this uncertain future. At Artesia, we’re committed to ongoing conversations about water demand in an uncertain future, through connecting, learning, and tackling the challenges ahead together. We’re eager to keep this conversation going with both existing and new collaborators—if you’re interested, reach out here.
