Is the property responsible for splashing water upstairs?

The property has no responsibility. For high-altitude parabolic objects, the property can only play the role of publicity and notification.

This is related to personal qualities. Under the premise of no safety accident, there is no way to investigate the responsibility. If you know which one can communicate at home, if you don't, there is no way.

If an accident happens, it will be easy to deal with if the responsible person can be clearly found.

If you can't, you can only sue the responsible person of the building through a lawyer and share the responsibility.