Invercargill City Council has been slapped with a formal warning after its broken pipe leaked wastewater onto the Bluff foreshore this year.

Environment Southland has revealed it hit the city council with the warning in September — more than four months after non-compliance was first flagged on the pipe.

The city council has pegged the pipe’s failure on the 5.9 magnitude earthquake which hit 40km north of Te Anau on 16 July.

However, concern over the pipe began during a routine inspection on 19 May, when Environment Southland manager Brad Thomas said its “poor condition” led to non-compliance.

Mr Thomas said the city council then notified Environment Southland on July 17 that the outfall pipe had failed, with treated wastewater discharging onto the Foveaux Strait foreshore.

The incident was investigated, a non-compliance recorded, and formal warning issued on 23 September, Mr Thomas said.

“Invercargill City Council is not currently meeting all the conditions of its consent to occupy the coastal marine area with the discharge pipe.

“These conditions relate to the long-term condition and appearance of the structure.”

Thomas said it was not possible to determine how much wastewater had ended up on the foreshore given it was not known exactly when the pipe failed.

The failure had occurred within the coastal marine area at Ocean Beach, Bluff, he said.

Council manager Matt Keil told Local Democracy Reporting damage to a nine-metre section of pipe was discovered the day after the July 16  earthquake.

Bluff's wastewater is released into Foveaux Strait through a 50m outfall pipe. Credit: Stephen Jaquiery/ODT.

The pipe was already scheduled to be relined the following week due to an earlier assessment which found it was at the “end of its life”, Keil said.

Normal operations were restored within a week, but the use of polyethylene pipes for the work resulted in non-compliance because the consent required concrete, he said.

“We are continuing to work with Environment Southland on a notice to fix.

“However, work to install the consented concrete pipeline has been delayed by poor weather in recent weeks.”

The 50m outfall pipe discharges treated wastewater into Foveaux Strait.

Bluff’s wastewater expired in December 2025 but has continued under a “status quo” arrangement with Environment Southland.

New legislation in August 2025 has allowed the existing consent to continue through to August 2028.

LDR is local body journalism co-funded by RNZ and NZ On Air.