The Queenstown Lakes District Council has been fined $24,225 for discharging wastewater from sewage pipes into Lake Wakatipu in 2017.
Council contractor Veolia became aware that a developer had allegedly illegally connected to the QLDC's wastewater network in March 2017.
Veolia later flushed the main pipe at Loop Rd, in Kelvin Heights, releasing debris and freeing the flow of the pipe.
Routine maintenance and inspections before the developer's alleged connection to the network found no issues with the pipes.
A resident reported a discharge from a manhole in the pipeline on August 3, 2017, which flowed over a popular cycleway/walkway and into the lake.
Veolia cleared the blockage in the sewer pipeline within about two hours of the discharge being reported, with the total amount leaked into the lake believed to have been 912 litres.
The area was cleaned and disinfected the same day the leak was reported, although the full duration of the discharge was unknown.
QLDC pleaded guilty to the charge after being taken to court by the Otago Regional Council and was convicted of the offence at Queenstown District Court today.
The council was ordered to pay the fine of almost $25,000, as well as additional court costs.
Judge Brian Dwyer said the offence resulted in a "small discharge'' that was not deliberate.
"As this particular discharge was into Lake Wakatipu it added an aggravating factor to the offence.
"There was a prompt and effective response on its [QLDC] part when the offence was brought to notice.''
He said the fact the lake was one of the country's "iconic'' bodies of water was an important part of his decision on the fine amount.
Both the ORC and the QLDC have been contacted for comment.
