Auckland's water authority Watercare says the overflow was caused by a "unique chain of events". Photo / NZME
Auckland's water authority Watercare says the overflow was caused by a "unique chain of events". Photo / NZME
Watercare has paid oyster farmers in north Auckland $1 million in compensation after wastewater overflowed at Warkworth and contaminated the Mahurangi River and Harbour.
Watercare has given the money to Aquaculture New Zealand to distribute to 10 oyster farmers affected by the most recent incident two weeks ago.
Watercare chiefexecutive Jamie Sinclair said the company was committed to making things right.
Sinclair said “a unique chain of events” led to the overflow. At the same time as a power surge tripped the Warkworth treatment plant’s pumps and caused storage tanks to fill and overflow, the monitoring and alert systems were “not operating as intended”.
The overflows continued from the afternoon of October 29 to the next morning.
About 1200cu m of wastewater overflowed, Watercare estimated.
Watercare did not know exactly how much got into the river, but estimated it was about 600cu m.
The Watercare boss says “a unique chain of events” led to the overflow in water at Mahurangi. Photo / NZME
The fault with the alert and monitoring system meant Watercare did not notice the issue “as quickly as it should have”, the council-controlled company said.
The pump station was eventually stabilised and normal operations continued on Thursday, October 30.
Sinclair said Watercare would appoint an external expert to work out the overall impact on farmers in the area.
“I’ve written to the farmers to reiterate my apology and confirm the payment of $1 million, as well as inform them of the external assessment process. After the incident, I said we were committed to making things right, and we’ve worked quickly to turn that commitment into action,” he said.
Watercare does not know exactly how much of the wastewater overflow got into the Mahurangi River, but estimates it was about 600cu m.
“We know this disruption comes at a very challenging time, just as the harvest season was at its peak. Today’s payment is intended to provide immediate support and we hope to have the assessment process complete before Christmas.”
Watercare offered the $1m compensation last Friday, and Aquaculture New Zealand signed an agreement today, Watercare said.
Watercare is conducting two investigations: one into the cause of the power surge, and one reviewing the alarm and monitoring system. External parties have been appointed to give independent feedback, the company said.
‘We’ve had many crises over the years, but none have compared to this’: Overflows whenever it rains, say farmers
Matakana Oysters owner Tom Walters spoke to the Herald after an overflow in May. He said the treatment plant overflowed whenever it rained.
Walters blamed Auckland Council and Watercare, saying “they have let the area grow out of control before the infrastructure was put in place” and now sewage overflows into waterways whenever it rains.
Watercare said at the time that it had great sympathy for affected businesses, and a major project was planned to reduce overflows into the Mahurangi River. This would be completed in 2028.
“Here is a situation where growth has killed an industry that’s been here for 50-plus years, an industry that helps the environment,” Walters said.
He said that over the past five years, what had been a small sewage overflow after 100 millimetres of rain had grown into a huge amount after only 10mm of rain.
Raphael Franks is an Auckland-based reporter who covers business, breaking news and local stories from Tāmaki Makaurau. He joined the Herald as a Te Rito cadet in 2022.
Sign up to The Daily H, a free newsletter curated by our editors and delivered straight to your inbox every weekday.
