Gangadhara, roughly translates the 'Bearer of the Ganges'.
A complex sequence of events led to bringing the heavenly river Ganga (Ganges) to Earth. The only trouble was, should Ganga fall on earth directly, the torrent would shatter earth.
Lord Shiva let Ganga fall on his head and wind through the matted locks, before making it flow gently to the earth.
This massive panel located on your immediate right of the Mahesh Murthy panel. This is one of the better survived sculptures of Elephanta panels, probably the only panel with the lower portions are intact.