Double checked just now, and I can ensure you that the reflection in the game actually works.
Did you run the directX install after the game install? Could be that you skipped it. Or possibly any other setting you're using.
Try changing rendering mode if the other one works for you and check water reflections again. If that doesn't fix it you should reinstall the patch again, possibly download the game installer instead and make sure everything is in place.
Only tip I can give at this moment.