The Dam Keeper (2014)

A young pig with an important job, and a new friend who changes everything. In a desolate future, one small town has survived because of a large windmill dam that acts as a fan to keep out pollution. The dam's operator, Pig, works tirelessly to keep the sails spinning and protect the town, despite abuse from classmates and an indifferent public. When a new student joins Pig's class, nothing will be the same again.