The Gore District Council will write to central government to outline what one councillor has described as the "funding impossibilities" now confronting them.

A report presented at Tuesday's council meeting estimated $465 million of capital investment in Three Waters infrastructure would be needed over the next 30 years.

That figure was considered the minimum and would cause the average annual water services bill in the district to rise from $1340 to $6770 by 2051.

Mayor Ben Bell said what was facing the council was "not a pretty picture".

The report noted the new government had signalled its intent to repeal Labour's reforms to Three Waters governance and management, but had not been clear about alternative funding methods to replace them.

"The most time critical project for an alternative funding model is the upgrades likely to be required when the council renews its wastewater discharge consents for the Gore and Mataura wastewater treatment plants," the report said.

"While the preferred option has not yet been identified, to meet new legislation and cultural expectations significant upgrades to both treatment plants are anticipated. The cost of these upgrades is currently estimated to be anywhere between $50 and $200 million.

"When considering the council has approximately $8-10 million in borrowing headroom remaining, it would seem almost impossible for the council to fund these upgrades solely through rates increases."

The council hoped to submit a consent application to Environment Southland by mid-2024 and would likely need to commit to a realistic timeframe for the upgrades as part of the consent renewal.

Gore's wastewater and stormwater networks were combined, which created capacity issues at the wastewater treatment plants during heavy rain and led to overflow issues into waterways.

Councillor Richard McPhail said the report was concerning.

"We are looking ahead 30 years at half a billion dollars of debt. The recommendation [in the report] says it's highlighting the funding challenges, but it's almost highlighting the funding impossibilities because we can't do anything other than go to central government. It's a pretty hard situation to face."

The council unanimously agreed to note the report, write to central government to highlight the issue and to request a meeting.

Reproduced with permission