I think I remember this mill! I cannot remember the DPCer or the challenge, but I know this, gosh darn it. This is really well done. Exposure range is great, and the colors are super rich but not so bright, so they add to the gloomy mood created by the mist and the ramshackle mill. Nice one.
The purple aura at the edges it a bit too much, and the sky in uninteresting.
I feel like the shutter speed is too long to make the water crisp, yet too short to make it dreamy. It might be due to the HDR process. Is this one (i.e. split into -2,0,+2 in PP) or more exposures merged?
Lastly, I think HDR should be applied in situations where it adds to the image - I am pretty sure that you could fit the histogram in one exposure.