Scrap channel (5)
I believe the answer is:
ditch
I believe this clue is a double definition.
'scrap' is the first definition.
(I've seen this before)
'channel' is the second definition.
(a small channel or trench in the ground)
(Other definitions for ditch that I've seen before include "Abandon - trench" , "Dug water channel" , "Get rid of; dug channel" , "Throw away (sl.)" , "Trench, dike" .)