Two Canterbury businesses have been fined $52,500 for allowing dirty run off from a housing development into Duvauchelle Bay, near Akaroa on Banks Peninsula.
Sicon Fergus Ltd and Tresta Holdings Ltd pleaded guilty in June for breaches of the Resources Management Act.
Scion was fined $30,000 and Tresta $22,000. A third company, Elliot Sinclair and Partners Ltd was found not guilty in the case.
The sediment came from the Totara Drive subdivision, sited on a hill overlooking Duvauchelle Bay.
Environment Canterbury (ECan), which prosecuted the companies, said both had disregarded "good advice" from officials and had been warned.
ECan director resource management Kim Drummond said: "The plume of dirty water that was washed into Duvauchelle Bay last May was a direct result of these companies disregarding good advice and not taking the appropriate steps to lessen the risk posed by forecasted poor weather.
"Erosion and sediment control is a critical factor in any works near water and they neglected to follow the plans laid out which would have stopped this from happening."
Judge John Hassan in his sentencing said neither company sought to deliberately pollute the environment and blamed errors of judgement.
"Neither Sicon or Tresta sought to deliberately pollute the environment. However, in various respects each of you demonstrated deliberateness in departing from your legal obligations.
Drummond said the case was a reminder to developers they have obligations to the environment.
"We don't like to see our waterways treated this way and if we find it happening we'll take those responsible to task over it."
The cultural impact of the incident on Te Runanga o Ōnuku was considered by Judge Hassan.
- The Press