A cleric with water domain gets ice storm at level 4
A cleric with watery death domain gets ice storm at level 3
A cleric with both can only add ice storm to the level 4 spells. An attempt to do so for ice storm at level 3 doesn't work.
(Apologies if this is already known. I was told to report it here.)
EDIT to add more info: Clerics get bestow curse at 3, and the domain version at level 4 for watery death does go into the level 4 slot.