Raid affected without water (4)
I believe the answer is:
arid
'without water' is the definition.
(I've seen this before)
'raid affected' is the wordplay.
'affected' is an anagram indicator.
'raid' anagrammed gives 'ARID'.
(Other definitions for arid that I've seen before include "(Of climate) dry" , "Desiccated" , "Parched, waterless" , "Lacking sufficient rainfall" , "Dry and withered" .)