Splatoon: Torrential Climb

One day a lone Inkling was minding their own business in the underground sewers of Inkopolis... when suddenly, the water levels begin to drastically rise! The city is not safe with the water levels so high! Who or what could have done such a thing? Your objective is to make your way to the top of the city by riding up walls, or sneaking through ink, and put a stop to this!