Much of the bill is for roading repairs, but water mains in West Harbour and on the Otago Peninsula also had to be repaired because of damage from slips.
"We are unable to provide a firm figure yet, as residual costs are still being incurred," a council spokeswoman said.
Climate and city growth general manager Scott MacLean said last month transport-related costs were $7.82m and a claim had been submitted to NZ Transport Agency Waka Kotahi for funding consideration.
A large slip in Maia knocked out about 500m of water main serving the West Harbour area on October 4 after persistent rain.
A workaround was soon set up, but a permanent solution will take some time to implement.
The council had already planned water main renewal work between Ravensbourne and Roseneath when the storm hit.
A water supply pipeline upgrade in Roseneath was awarded to Downer in December and construction started in January.
The council said the upgrade was part of a larger project aimed at enhancing the water supply from Dunedin to Port Chalmers.
"Future stages will improve resilience by relocating pipelines from private property to public areas and away from landslip risks," it was stated within an agenda for yesterday’s infrastructure services committee meeting.
About 6.5km of pipe between Ravensbourne and Roseneath would be renewed over the next three years, the council said on its website.
On the Otago Peninsula, the council plans to shift the water main away from where it is vulnerable to slips.
Staff were working to determine the most appropriate pipe route to minimise potential for slips and other hazards that could affect water supply resilience in the area, a council spokeswoman said.
Construction in Irvine Rd is due in the 2025-26 financial year.
Any work in Portobello Rd would be expected to happen the following year, the council said in the infrastructure services agenda.
"It is anticipated that the existing water main will stay in its current location to supply water to existing residences, while the new pipe will provide a resilient supply to the Macandrew Bay reservoir."
Otago Peninsula Community Board chairman Paul Pope said staff had been exceptional during emergencies and when there were pipe breakages.
Mr Pope said Macandrew Bay had land stability issues that affected pipes — anything that could be done to enhance security of supply would be "a bonus for us".
The Otago Regional Council said $213,970 had been spent to date on repairs after the October flood.
A staff report for yesterday’s meeting said the updated cost estimate for all flood damage repairs was $2,364,000, slightly less than the $2,540,000 estimated late last year.
This was funded by flood scheme reserves, the report said.
Alternative funding sources were sought through central government — the National Emergency Management Agency and the Regional Infrastructure Fund.
