Damage in a way that needs repair to the pool (7)
I believe the answer is:
pothole
'damage in a way that' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'repair to the pool' is the wordplay.
'repair' is an anagram indicator (letters are fixed or repaired).
'the'+'pool'='thepool'
'thepool' is an anagram of 'POTHOLE'.
'needs' is the link.
Can you help me to learn more?
(Other definitions for pothole that I've seen before include "Narrow cave" , "Small pit in road surface" , "Deep water-carved cave" , "Sorrow" , "Effect of subsidence" .)