Landing stage ripe for redevelopment (4)
I believe the answer is:
pier
'landing stage' is the definition.
(structure by the sea)
'ripe for redevelopment' is the wordplay.
'for redevelopment' indicates anagramming the letters (I've seen this in other clues).
'ripe' with letters rearranged gives 'PIER'.
(Other definitions for pier that I've seen before include "Seaside platform" , "Platform built out from the shore, supported on piles" , "Wharf jutting out into water" , "Platform out to sea" , "Support member" .)