The European put the water drain the wrong way round (8)
I believe the answer is:
spaniard
'the european' is the definition.
(someone from Spain)
'the water drain the wrong way round' is the wordplay.
'the water' becomes 'spa' (I've seen this before).
'the wrong way round' says the letters should be written in reverse.
'drain' backwards is 'niard'.
'spa'+'niard'='SPANIARD'
'put' is the link.
(Other definitions for spaniard that I've seen before include "Malaga man or woman, perhaps?" , "A native of Iberian country" , "Type mostly found in Madrid" , "Native of southern European country" , "Slope-measuring instrument" .)