For what it's worth from http://askelm.com/temple/t001211.htm

To these Jews in the seventh, eighth and ninth centuries, this is where the ruins of their Temples and the real "Tomb of David" were located — over and around the Gihon Spring. They even had a synagogue in a cave that led to underground passages in the area. And they were right. Indeed, the Jewish authorities did not abandon the area around the Gihon Spring and its tributary waters of the Shiloah channel until the major earthquake of 1033 C.E. that destroyed the early Eudocian Wall constructed in the Byzantine period. That destruction by the earthquake made the southeastern region around the Gihon Spring to be outside the walls of Jerusalem. The whole southeast quadrant became unprotected. This opened the region to attacks by the Seljuk Turks and other enemies.

And then something happened that was quite remarkable and ritualistically devastating. In that period, the waters of the Gihon Spring turned bitter and even septic (between 1033 C.E. and 1077 C.E.). The interpretation placed upon this event was as if God himself had turned the former "waters of salvation" into a corrupt liquid inside the precincts of God’s own House. The Jewish authorities were well aware of the account in Numbers 5:11-31 that showed bitter waters were associated with the adulterous woman in Temple symbolism. With this final ritualistic setback to their religious customs, the Jerusalem Academy abandoned Jerusalem and moved to Damascus. To the Jewish authorities by 1077 C.E., there was nothing of contemporary holiness left to the former Temple area over the Gihon Spring. Jerusalem was later taken over by the Christian Crusaders in 1099 C.E. and no Jew was able to step inside Jerusalem for the first 50 years of the Crusades.