rebekah20p – You said “i understand that because a garage is not a livable area the OC doesn’t need to fix it as it doesn’t need to be waterproofed etc.”
In my opinion the OC does need to fix the leaking issue in your garage. I am assuming your garage is an internal subterranean garage. The mere fact that the area is not a livable space should not excuse the OC from their duty to keep this area dry. If the area was dry when the property was built and was dry when you purchased your property and now it is wet then that indicates that a problem has developed with the original waterproof membrane and maintenance and repair is required.
Water leaking may cause structural issues. Also, your property could become damaged if the garage floor is becoming wet, and as you mentioned, the floor could become hazardous and slippery.
If the garage wall – floor junction is below ground level and would be difficult to repair from the outside of the wall then you may be interested to know that there are ways to waterproof the wall and the junction from the inside of the wall (the negative side). I have had a very favourable first hand experience with an injectable negative applied waterproofing.
You might like to suggest this method to your OC if it is applicable to your situation.