Water-type moves do not work on the Pokémon. Instead, they restore 1/4 of its max HP.
Water Absorb (Japanese: ちょすいWater Storage) is an Ability introduced in Generation III.
Effect
In battle
Generation III
When a Pokémon with Water Absorb is hit by a damaging Water-typemove, its HP is restored by one quarter of its maximum HP, and the move will have no effect on that Pokémon (if a Pokémon with this Ability already has full HP, the Water-type move will do nothing).
Water Absorb will not activate if the Pokémon is protected from the Water-type move.
Generation IV onward
Water Absorb will now also activate when a Pokémon with it is hit by a Water-typestatus move (although none targeted an opponent until Soak was introduced in Generation V).