Hozu:
But only insofar as that Ability does not change the target of Water Spout, since Water Spout has the range "all opposing Pokémon" rather than "single Pokémon except user": "Water-type attacks ... by other Pokémon
with a range of 'single Pokémon except user' that could target this Pokémon are directed to this Pokémon instead of to any other target of that attack." Moreover, even Water Spout is affected by Storm Drain when the attack's range does include the Pokémon with that Ability: "Whenever a Water-type attack ... by another Pokémon targets this Pokémon [etc.], this Pokémon's Special Attack is raised by 1 stage [etc.]."