Water Compaction (Japanese: みずがため Water Fortifying) is an Ability introduced in Generation VII. It is the signature Ability of Sandygast and Palossand.
When a Pokémon with Water Compaction is hit by a Water-type move, its Defense rises by two stages. No immunity is granted to Water-type moves, however.
It will activate for every hit of Water Shuriken.
Water Compaction has no effect outside of battle.