The council adopted a $1.5b programme in its 2021-31 long-term plan and is in the early stages of working out what will be needed for 2024-34.
It was "likely closer to $2b", council chief executive Sandy Graham said yesterday.
"We’re trying to build a balanced programme that delivers what we need to do," Ms Graham said.
"At the same time, it has to be affordable."
Council staff are working on draft budgets before councillors approve the 2024-34 draft long-term plan for public consultation.
Among factors they will need to consider are cost pressures, inflation, interest rates, rating revenue needed, city growth, government policy about Three Waters and where money is best directed for infrastructure, facilities and services.
The council will also need to be mindful of its growing debt burden.
Councillors are due to discuss updated draft capital expenditure budgets at the end of next month.
In the meantime, details of the draft capital expenditure programme for 2024-34 are being refined and could change.
Significant uncertainty is attached to the Three Waters component, which is shaping to be about half of the full programme’s cost, amid government reform.
Regarding Three Waters, Ms Graham said the council did not yet know "how it may or may not be able to be funded".
The government plans to repeal some of the previous government’s legislation about water reform and new Minister of Local Government Simeon Brown has said a key principle of his plan was "fit-for-purpose service delivery models and financing tools".
Three Waters — drinking water, wastewater and stormwater — covers pipes and treatment plants, for which upgrades can be expensive.
The council had been shaping to include Three Waters activities in its plan for the first two years only, reflecting existing legislation.
However, the minister issued an instruction that Three Waters activities should remain on the books of councils for the full 10 years.
Ms Graham said Three Waters was one part of an integrated programme and Dunedin City Council chief financial officer Carolyn Allan said the council had to keep in mind the market’s ability to deliver work planned.
Growth scenarios also needed to be considered.
However, it has been signalled transport spending will need to be focused on existing roading and footpath networks.
Ms Graham said this partly reflected some were "in the state where they need a bit of work".
Building a library complex in South Dunedin and an upgrade of kerbside rubbish and recycling collection will be two projects included in the long-term plan.
Ms Graham confirmed creating a new landfill at Smooth Hill would also be in the draft programme.
