"Experts warn that decaying infrastructure and decades of underinvestment have made the [UK]’s water supply a vulnerability that could be exploited, in particular by Russia. That scenario has been underscored by heatwaves and drought, exacerbated by climate change.
A loss of supply could occur as a result of deliberate contamination, a cyberattack targeting automated systems, infrastructure failure caused by power loss or fire, or environmental factors such as drought."
https://www.thetimes.com/uk/environment/article/water-risk-shortage-5xzr3spzk