Perhaps did butterfly scheme initially drain fen area? (9)
I believe the answer is:
swampland
'area?' is the definition.
(I have seen 'Waterlogged area ' mean 'swampland' so perhaps 'area' could also mean 'swampland')
'perhaps did butterfly scheme initially drain fen' is the wordplay.
I cannot really see how this works, but
'scheme' could be 'plan' (synonyms) and 'plan' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for swampland that I've seen before include "Waterlogged area" , "boggy area" .)