The UK aims to capture and store 20–30 Mt $$\hbox {CO}_{2}\hbox {e}$$ annually and produce 10 GW of low-carbon hydrogen by 2030. This study evaluates the potential water resource impacts of these decarbonisation efforts across five UK water company regions: Anglian Water, Northumbrian Water, Severn Trent Water, United Utilities, and Yorkshire Water. Projected $$\hbox {CO}_{2}$$ capture and hydrogen production rates are obtaine...