Whanganui District Council had agreed to underwrite an $11.6 million shortfall in the Sarjeant Gallery redevelopment project just weeks before a further $12 million grant from the Provincial Growth Fund was announced to cover the cost.
The decision was made at an extraordinary meeting in June - a meeting from which the public was excluded.
The total cost of the project has been put at $49.3 million. The further $12 million offered by the Provincial Growth Fund on July 3 has been scaled back to $11.6 million, to meet the exact amount of the shortfall, redevelopment director Gaye Batty told Whanganui District Council's property and community services committee on September 22.
Council's contribution will now be $5 million, plus contingencies.
Batty said the project has so far cost $228,000 in contingencies, and councillor Philippa Baker-Hogan asked whether that would increase the ratepayers' capital contribution to the project.
The council had agreed to pay contingencies, up to a predetermined amount, Mayor Hamish McDouall said.
"We committed to that very early on, as part of the earthquake strengthening. There's nothing confidential about it."
Baker-Hogan also wanted to know how much the finished gallery would cost to run.
Council chief operating officer Bryan Nicholson said that was being worked out, and Baker -Hogan was told it would be part of Long Term Plan discussions.
Meanwhile, loose sandy soil has been flowing into a hole excavated under the Sarjeant Gallery's dome to make room for a concrete foundation.
The soil type under the gallery building is one of the risks of the gallery's redevelopment project.Massive steel members have been driven into the sand, to test its resistance and find out what kind of battering will be needed to keep it stable.
Structural engineer Ian Brown is on site.
Another risk in the building process is the type of temporary work that will be needed to hold the soil and fragile 1919 building in place while it is strengthened.
The third risk is that Covid-19 lockdown costs and restrictions will delay progress and raise the cost.
Meanwhile, at the work site, archaeologist Michael Taylor and his Tupoho monitors left in mid-August. A piece of pounamu and a greenstone adze were found.
Security was stepped up and a fossicker was caught on video. Inquiries on that are continuing.
Tupoho is also to offer advice on a narrative that will inform art works and landscaping at the finished site.
Artists and others are deciding how timber from protected oak trees felled for the development will be used inside the buildings.
The gallery's extension wing is programmed for completion in August 2022, and the original gallery building for March 2023.