A water separator reduces a water content of an air stream, which is used in an HVAC unit for a vehicle. The water separator includes a diverter wall and an adjacent wall spaced from the diverter wall to define an air passage. The diverter wall has a terminal end extending into the air passage for changing a direction of the air stream flowing through the air passage to separate water droplets from the air stream to reduce the water content of the air stream. A gutter is coupled to the terminal end of the diverter wall and extends into the air passage. The gutter defines a drainage channel configured to receive the water droplets that form on the diverter wall for preventing the water droplets from reentering the air stream flowing through the air stream passage.