This story draws on reporting by The Southland Tribune.

The annual cost of running Te Unua Museum of Southland has risen to close to $6 million, well above the $4.1 million Invercargill City Council first set aside for its museum and gallery operations, and the mayor says the project will add about 10 per cent to rates once debt repayments are included.

The figures were reported by the Southland Tribune on 2 November, drawing on comments from Mayor Tom Campbell. The near-$6 million figure covers operating costs only. It does not include building maintenance, insurance, running the cafe, depreciation or servicing the debt raised to build the museum.

Campbell said the roughly $2 million jump in operating costs reflected a bigger building with higher heating and staffing needs, and that inflation since 2022 meant the original budget bought less by the time the doors open. Staff have been asked to find savings elsewhere in the council's operations to limit the effect on ratepayers.

The council expects to confirm its 2027-28 rates rise in about five months. Campbell told the Tribune the museum's impact meant the coming year would be a hard one.

The project dates to 2022, when the previous council approved an $87 million package. It covered three parts: a 3550-square-metre museum building beside Queens Park, a new tuatarium in the park itself, and a new collection store at Tisbury. Campbell was not a councillor at the time. He said later councils could have trimmed the cost by shrinking the building or opting for a more conventional display, but chose to keep the size and pursue a modern, digital-led design.

Asked whether today's council would make the same call, he said it might have chosen something smaller, but added that in 20 or 30 years the city would likely have greatly regretted not building it.

The pressure is already shaping other decisions. Next year, as part of the 2027-2037 Long-term Plan, councillors will debate the future of Rugby Park, where years of deferred maintenance have left the ground needing significant investment. Campbell said there was no final decision, but the mood around the table was to proceed, and that the council could still afford some major projects even if it could not do everything.

Agenda papers for Monday's extraordinary council meeting show councillors are due to make budget decisions for the Long-term Plan on 24 November, including funding for Great South, the regional development agency.

Te Unua is due to open in 2027. Ministers toured the near-complete building last month, and the council last week released details of the cultural narrative artworks by Riverton carver James York that will be woven through the building inside and out.

The council will consult the public on the Long-term Plan, including the museum's operating budget, in the first half of next year.