Compare the power blocks; this looks like it's been heavily reskinned. The power labeled as "Freezing Current" is actually freezing burst, from Heroes of the Fallen Lands. You're on your own for the rest.

However, if it's a water-themed spellcaster you're looking for? Have a look at the sorcerer (elementalist) in Heroes of the Elemental Chaos. One build for each classical element, water included, though of course I prefer FIRE because of its absolute superiority among damage types.