The area isn't developed as well (8)
I believe the answer is:
artesian
'well' is the definition.
(artesian well is a kind of well)
'the area isn't developed' is the wordplay.
'developed' is an anagram indicator.
'area'+'isnt'='areaisnt'
'areaisnt' is an anagram of 'ARTESIAN'.
'as' acts as a link.
(Other definitions for artesian that I've seen before include "(Well) flowing under natural pressure" , "Type of well made from a sea train" , "Type of deep well" , "(Well) fed by pressure" , "Type of well that doesn't need a pump" .)