I believe that 'rain' is the weather theme of this photo, so the challenge is met in that aspect with no problems :)
The composition on this shot is good, and the exposure is fine as well. Technically, there is nothing wrong witht he image. I think the image is simply lacking strength. There doesn't seem to be anything here that has any 'wow' factor or visual impact for the viewer.
Tighter on the water dripping from the spout would have fit with the title a little better. And either a faster (freezing the drops) or slower (giving them a stronger sense of motion) sutter speed might have given a better effect to the drops.
looks like the subject ought to be the rain falling from the gutter..would have been more effective if we could have captured them mid-fall in suspended animation, and if that isn't the subject then... forgive my irrelevant comments!