In the time when the Temple stood in Jerusalem, there was a ceremony called the Simchas Beis HaShoeivah. The central aspect of the event is, as the name implies, the drawing of water and pouring it as a libation onto the Alter. The event would continue with dancing for the greatest members of Yisrael, and musical festivities. The entire event is described in the fifth chapter of Mesechet Sukkah.
Many communities today hold what they call a Simchas Beis Hashoeivah as well. However, aside for singing and dancing (almost universal among every Jewish get-together), it seems to share nothing inherently in common with the event held in the Temple. In general, the notion of creating a mock- Temple event seems a little peculiar.Is there a source for the contemporary practice of a "Simchas Beis Hashoeivah" celebration? What is the earliest mention of such an event, post the destruction of the Temple?