No these aren’t the same risk calculations and in fact use different measurement language - this is important because it’s an actual argument that is fallacious and regularly used.
This is the same poorly argued version of: “Milk is a gateway drug” when we’re evaluating a claim like “x% of y users used z drug before starting y, therefore z induces y” but actually irrelevant when asking for causal precursors.
That is a completely separate type of claim and argument.
“Risk to health” increases with abstention of water, the direct opposite of the mechanism for alcohol.