The blocked pipe ran through a block of medium density housing in Bonython, roughly 21 metres south of the public utility's main sewerage line.

According to documents tendered in the ACT Civil and Administrative Tribunal, Icon Water argued it had never owned the pipe and had no responsibility for its maintenance and cleaning.

But the property owners argued the pipe must have been approved by the public utility, and if that wasn't so, it would have been negligent not to approve it or register it.

The owners told the court they were never told about the sewerage pipe or of any responsibilities they had for its maintenance.

"The absence of documentation and advice concerning the presence of the easement has disadvantaged all the parties," ACAT Presidential Member Elizabeth Symons said.

"As a consequence, they have not come to an agreement as to their respective responsibilities for blockages which occur in the sewerage pipe."

But the appeals tribunal found there was not enough evidence to find Icon Water was the legal owner of the sewerage pipe and the initial order to reimburse the owners $1156.42 was overruled.

The court found authorities failed to note the easement on property titles as there was no evidence certificates were sought or provided.

Correction: An earlier version of this story said Icon Water was ordered to reimburse the property owner $1156.42. The order was overruled on appeal.