Is it ever mutar for a chazzan to drink water sometime during a tefilla to help his voice? Personally, I sound better and feel better after having drunk a bit. What about during Pesukei D’Zimra in preparation for Shacharis or between Shacharis and Mussaf? Would Kiddush always be necessary even for just water?
After davening Shacharis, one must make Kiddush before drinking water.
However, this applies only to drinking water for the purpose of quenching one’s thirst. If a person is not thirsty, and wishes to drink water for the purpose of clearing his throat, there is no obligation of kiddush even after Shacharis.
Before Shacharis, there is no obligation of kiddush, and it is permitted to drink water before davening. During pesukei de-zimra, the problem is the obligation of reciting the shehakol blessing, and similar principles to the above will apply.
If the purpose of drinking is only to clear the throat, no berachah (shehakol) needs to be made, and where required one can drink a little during pesukei de-zimra, without concern for a hefsek (interruption). Poskim discuss whether an ‘action’ (ma’aseh) constitutes a hefsek, and the general concensus is that it does not (see Shut Mekor Chayim, Orach Chaim 2, concerning the act of writing).
If, however, one feels thirsty, a shehakol needs to be made, and one should avoid this during pesukei de-zimra.