Flood leads to some people abandoning their estates (5)
I believe the answer is:
spate
'flood' is the definition.
(synonyms)
'leads to some people abandoning their estates' is the wordplay.
'leads to' says to take the initial letters.
The first letters of 'some people abandoning their estates' is 'SPATE'.
(Other definitions for spate that I've seen before include "Flood; sudden burst" , "Sudden forceful flow" , "A sudden flood or rush" , "Rush, flood (of river)" , "A torrent of tapes" .)