Wellington Water crews are still working to tackle problems with a collapsed sewage and wastewater pipe in the central city.
The broken pipe serves the whole city and has been used for decades to take waste to the main pipeline that goes into the Moa Point treatment plant.
Sewage and wastewater has been pouring into the harbour at up to 100 litres a second since yesterday morning. Up to 5 million litres a day of wastewater and sewage could keep pouring into the harbour for days.
People might not be able to swim safely in parts of Wellington Harbour until next year.
Wellington Water crews worked overnight trying to divert sewage and wastewater from the broken pipe.
We also thank residents and businesses in the affected area for doing everything they can to reduce their water use. https://t.co/5E1NJ4Yvw6— Wellington Water (@WgtnWaterNZ) December 20, 2019
The organisation's chief waste water advisor Steve Hutchison said the cause of the break was not yet known and the repair time was also uncertain.
Hutchison said people should stay out of the water in the inner harbour - from the top of Roseneath through the waterfront to the port - until testing determined how far contamination had spread.
The discharge points are near the dive platform and Whairepo lagoon on the Wellington waterfront.
Local iwi have placed a rāhui on the entire Wellington harbour.
Kura Moeahu of Te Āti Awa said the rāhui was a precaution to keep the public safe.
Wellington Water chief executive Colin Crampton said the pipe collapse had hit at a terrible time, because many people wanted to swim in the harbour over the summer break.
Central city businesses and residents have been asked to conserve water to reduce pressure on the wastewater system.
Please expect significant delays through the CBD, particularly on Vivian St.— Wellington Water (@WgtnWaterNZ) December 20, 2019
SH1 traffic should use Cambridge Tce, Wakefield St, Jervois Quay, Waterloo Quay and Aotea Quay as alternative routes during this time. https://t.co/3OIvKkxBjr
Willis St between Vivian and Manners streets and Ghuznee St between The Terrace and Victoria St are closed while work on the pipe continues.
Significant traffic delays are expected and people driving to the airport should allow more time.