Nice shot. The colors are very nice. Yes, you can correct the horizon in photoshop. But, I disagree that this image is off level. It's a stream that's running from upper left to lower right, so the horizon line seems to run a bit overly clockwise. Also, there may be a bit of barrel distortion, which seems most apparent in the reflections at the lower left. However, if you look at the right side trees, the house, and the reflections, it appears that the verticals are properly plumb. I wouldn't rotate this image at all.