In spoken German, it is very common to answer basic mundane yes-or-no question with an elliptical construction like this: "Willst du noch ein Bier?" "Ja, will ich." This works for haben, ...
I want to say: Yes, get water please in German, but I think my attempt is wrong. I'm speaking to one other person informally: Ja, bitte Wasser kriegt. Is this right? Do I conjugate like ...