Your highest level Wizard is only level 39, young Wizard. You have some work to do, and a few levels to gain, before you'll be ready for the challenge that is Waterworks.
As Professor Greyrose said in the post she said "Your highest level Wizard is level 39."
You must be a Minimum of level 60 to start the Waterworks. If you are level 60, go speak to Blad Raveneye and he will lead you to the Waterworks where you defeat Sylster