The work of creative navvies, forming a clan (5)
I believe the answer is:
canal
'the work of creative navvies' is the definition.
I can't judge whether this definition defines the answer.
'forming a clan' is the wordplay.
'forming' is an anagram indicator.
'a'+'clan'='aclan'
'aclan' is an anagram of 'CANAL'.
Can you help me to learn more?
(Other definitions for canal that I've seen before include "eg Grand Union" , "Artificial waterway as at Panama (5)" , "Manmade flower" , "Man-made strip of water" , "Duct" .)