Settlers from Europe didn't drink too much water in colonial days. Alcholic beverages were the norm for liquid nourishment. Most colonists (at least the men) consumed hard alcohol, wine, beer, and other spirits on a regular basis. Even Ben Franklin got in on the act:
First, a note from Mr. Franklin: "The Phrases in this Dictionary are not (like most of our Terms of Art) borrow'd from Foreign Languages, neither are they collected from the Writings of the Learned in our own, but gather'd wholly from the modern Tavern-Conversation of Tiplers. I do not doubt but that there are many more in use; and I was even tempted to add a new one my self under the Letter B, to wit, Brutify'd: But upon Consideration, I fear'd being guilty of Injustice to the Brute Creation, if I represented Drunkenness as a beastly Vice, since, 'tis well-known, that the Brutes are in general a very sober sort of People."
The Natives, on the other hand, were very proficient in keeping their water clean. The drivers of the economic engine of the day didn't care about anything or anyone getting in the way of the sugar and tobacco trades. Guns and cheap booze did play a part in keeping the natives down. As did disease: Smallpox, measles, chicken pox. Diseases that settlers were basically immune to. When they got it....they died! This was not known by the settlers when colonisation first began. Through time and observation these devasting results were seen as a weapon. And we all know where that leads....!