It looks totally gorgeous anyway
If you insist on doing a reflection, though, have you considered making a copy of all the visible parts, flipping it vertically, stretching it till the perspective looks right, deforming it with ripples, then masking the water and deleting what isn't required of it?
Then adjusting the blend mode and transparency till its just a suggestion of a reflection.
Don't worry if it doesn't work - its only a suggestion. Like I said, it looks terrific anyway
EDIT: I know the perspective means that you only really need to reflect the city walls - the closest bit to the water, because most of the things behind that will most likely be hidden from the water and won't be reflected. You might see the tops of the towers.
Its a tricky one!
EDIT 2: Is there not a reflection tool in PS that you could use on the parts of the city that will reflect? Maybe that has ripple effects thrown in if you have?