Nothing goes on to East African waterway (4)
I believe the answer is:
nile
'african waterway' is the definition.
(I've seen this in another clue)
'nothing goes on to east' is the wordplay.
'nothing' becomes 'nil' (eg nil is zero in football).
'goes on' is a charade indicator (letters next to each other).
'to east' becomes 'e' (abbreviation).
'nil'+'e'='NILE'
(Other definitions for nile that I've seen before include "Take a line to the river" , "River (which is originally blue and white)" , "Long river" , "River at Luxor" , "Current" .)