The way (cold) water is referred to does not change depending on the type of water, such as whether it is for drinking or not.
Turning 水 into お水, 金 into お金, 風呂 into お風呂 and so on are examples of beautified language (美化語), which is a subset of keigo in a broad sense. Naturally, while you would hear お水 often at a restaurant, people tend not to refer to water in a lake as お水. But this does not mean there is a semantic difference between 水 and お水.
While 美化語 may be used in news articles with a casual and friendly tone, they are not usually used in articles with a formal and serious tone, such as the one you linked to.