Do find West Country river charming (7)
I believe the answer is:
execute
'do' is the definition.
(to execute something is to do it)
'west country river charming' is the wordplay.
'west country river' becomes 'exe' (the River Exe).
'charming' becomes 'cute' (I've seen this before).
'exe'+'cute'='EXECUTE'
'find' acts as a link.
(Other definitions for execute that I've seen before include "Discharge" , "Put (plan) into effect; kill (a condemned person)" , "Put to death or carry out, say plan" , "Put to death - put into effect" , "Finish off" .)