Regional council compliance manager Alex Miller said the prosecution highlighted how important it was for meticulous care to be taken during construction projects to avoid environmental impacts.
"This case shows the environmental and cultural flow-on effects of wastewater discharges.
"However, we recognise CPB worked alongside tangata whenua throughout the justice process and the planting programme is a positive response to the charges," Miller said.
Judge Dwyer said the discharge of raw sewage into our waterways was a well-recognised cultural offence to Māori.
"Such discharges are commonly offensive to the wider community," Judge Dwyer said.
"CPB has a comparatively high level of culpability arising out of the failures of both its employees and its own procedures which failed to ensure that a critical safety essential was followed."
In the statement, the regional council said it encouraged anyone who noticed wastewater overflows or other pollution matters to call the 24/7 Pollution Hotline on 0800 884 883.
Under the Resource Management Act, regional councils and unitary and territorial authorities have primary responsibility for compliance, monitoring and enforcing the act to help manage natural resources and protect the environment.