My name is ***** ***** I am a NSW Solicitor. Thank you for your question, and will do my best to assist you with your question. Please understand this is not legal advise but a guide to assist you.
If you can show that the damage was caused by the neighbour moving the water into the land and it caused the failure then they are liable under nuisance.
Here is some information about nuisance in SA
You have to advise your insurer of the situation and have them investigate. If they believe it is the neighbour that caused it you should not have to pay the excess and the insurer will chase the neighbour for the cost of the repairs.
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