Property developer Northlake Investments is not ruling out an appeal after being found guilty of discharging contaminants into the Clutha River nearly two years ago.
The company and its contractor, Civil Construction Ltd, were prosecuted by the Otago Regional Council (ORC) after the discharge from a site within the Northlake subdivision, about 2km east of Albert Town, on August 17 and 18, 2017.
Regional council staff found an overland flow of silt and sediment-laden water entering the river, causing discolouration for more than 500m.
Inspections the next day found the discharge was continuing, but at a reduced flow.
Civil Construction admitted the charge - while blaming the Northlake's stormwater system design - and was convicted and fined $25,500 in January.
Northlake defended the charge at a week-long trial before Judge Brian Dwyer in the Environment Court, in Queenstown, in April and May.
The court heard evidence of how the discharge flowed an estimated 1.5km from the boundary of the company's 108ha property on the corner of Aubrey and Outlet Rd.
It flowed across land owned by Exclusive Developments Ltd, then over a Department of Conservation reserve before reaching the river.
In his decision, Judge Dwyer said he was satisfied the company did not take the ''reasonable precautions of a prudent developer'' to prevent the discharge, and having an awareness such an event could occur, did not investigate and take proper preventive measures.
A spokeswoman for Northlake Investments told the Otago Daily Times in an email it was reviewing the decision and considering all options, including appeal.
Sentencing is set down for September 2 in Queenstown.
In a media statement, ORC chief executive Sarah Gardner said the decision showed the importance of environmental management during development.
The council was ''increasingly concerned'' about water quality in areas where rapid urban development was causing high levels of disturbed sediment.
''It's crucial that developers have robust sediment management systems in place to avoid water contamination.
''Water is ORC's number one priority ...
We are taking our responsibilities - and the responsibilities of all Otago in appropriately managing water resources - very seriously, and we are prepared to prosecute offenders where necessary.''
