Napier residents were asked to conserve water after severe weather affected the city's sewers and pump stations.

Before 11am on Saturday, the Napier City Council issued a warning to residents to reduce their water load, and asked people to not take baths, or flush toilets unless "absolutely necessary".

The city's sewage infrastructure had not experienced any significant overflows, but faced problems because of power outages to their wastewater pump stations.

Council director of infrastructure Jon Kingsford said their primary cause for concern was the high risk of further power cuts, which would mean a reduced, or loss of pumping capacity at critical wastewater pump stations.


"Although the degree of rainfall over the weekend would normally not affect our wastewater network, the power cuts meant we needed to mobilise additional staff and engage standby power generation and pump through the backlog of waste water."

Under normal conditions, with no heavy prolonged rain, the station's back-up systems could usually last for up to eight hours. With heavy rainfall, the network was capable of storing flow for 4-5 hours.

"There was some concern that prolonged power cuts and the torrential rain that was forecast may have resulted in overflows, even though the network had not reached a critical point at that time."

Yesterday afternoon, the warning was lifted and residents were able to resume normal water usage activities.

As well as asking residents to conserve water, Mr Kingsford said council were exercising other measures including "additional standby generation".

"We were really pleased with the response from the people of Napier and grateful that they acted quickly on our request."

Mr Kingsford said there was no risk to drinking water.

The City services team, and other contractors, had worked in difficult and challenging conditions, with early starts and long hours, to ensure the network continued to deliver an adequate level of service.

A Hastings District Council spokeswoman said their network might have experienced isolated incidents, but no major events.