The CID's unorthodox channels (7)
I believe the answer is:
ditches
'channels' is the definition.
The definition and answer can be both man-made objects as well as being plural nouns.
Perhaps you can see a link between them that I can't see?
'the cid's unorthodox' is the wordplay.
'unorthodox' is an anagram indicator.
'the'+'cids'='thecids'
'thecids' is an anagram of 'DITCHES'.
Can you help me to learn more?
(Other definitions for ditches that I've seen before include "Long narrow excavations" , "Trenches" , "Abandons" , "Rejects" , "Gets rid of" .)