Water in Ireland rising (4)
I believe the answer is:
erie
'water' is the definition.
(I know that Erie is a water)
'ireland rising' is the wordplay.
'ireland' becomes 'eire' (poetic name for Ireland).
'rising' is a reversal indicator (going up in a down clue).
'eire' in reverse letter order is 'ERIE'.
'in' is the link.
(Other definitions for erie that I've seen before include "Lake between Canada and the US" , "N. American lake" , "Superior companion" , "One of the Great Lakes" , "Spooky-sounding" .)