Planned in Hebridean island to accommodate wine lake (11)
I believe the answer is:
intentional
'planned' is the definition.
(thesaurus)
'in hebridean island to accommodate wine lake' is the wordplay.
'hebridean island' becomes 'iona' (island of the Hebrides).
'to accommodate' indicates putting letters inside.
'wine' becomes 'tent' (type of Spanish wine).
'lake' becomes 'L' (geographical abbreviation).
'in'+'iona'='iniona'
'iniona' placed around 'tent' is 'intentiona'.
'intentiona'+'l'='INTENTIONAL'
(Other definitions for intentional that I've seen before include "Done on purpose" , "Deliberate" .)