No wells can be like a river in flood! (7)
I believe the answer is:
swollen
'in flood' is the definition.
(synonyms)
'no wells can be' is the wordplay.
'can be' indicates an anagram.
'no'+'wells'='nowells'
'nowells' is an anagram of 'SWOLLEN'.
'like a river' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for swollen that I've seen before include "Engorged" , "Protuberant" , "Distended, expanded" , "Puffy" , "Greatly distended" .)