Welcome to the PlaneShift forums.
Many people suffer from a lag there. It must be related to some older graphic card chipsets, not being able to handle parts of this geometry detail level or the steam effects well.
Usually it helps using "Third person follow" mode (M), looking down (PgUp/PgDn), and moving the camera away (mouse scrollwheel), so that the waterfall is out of your viewing angle, but you still have a good overview of your surroundings.