The colours are beautiful, but the picture is out of focus and there's a fair bit of noise, especially at the horizon and the waterlines. I think you took this in low light without a tripod? Something to steady the camera might have helped. Great colours though.
i see a lot of jpeg artifacts here, probably because of post processing... if you save your original as an uncompressed tiff, do all of the manipulations with it, and then save the final version as a jpeg, it should help the problem... as it looks now, i can only give it a 2, sorry...
I like the composition which kind of gives an impression of the canals in the Netherlands, but I find the exposure too dark, even though it appears to have been taken at dusk. Also, I believe it is too out of focus (could be from being so dark).