At this week’s council meeting, staff suggested a three-pronged approach for short-term mitigation.
This would include a diversion of the Bay View Rd and New St stormwater systems to a new pipe directly to the Portobello pumping station ($1.9m), upsizing the Forbury Rd pipe ($12m) and disconnecting the Hillside Rd mains and pumping to the Orari St outfall ($15.2m).
The draft budget also includes $15m for future medium-term flooding alleviation work in South Dunedin, meaning the budget would – once confirmed – include $44.2m for work.
This proposal represents a change in debt of $11.714m compared to the draft budget.
Mr Radich said the time for talking about the issues had long finished, and now was the time for action.
"If it’s a difference between knee-height and ankle-height — that’s the difference between my house flooding and not flooding."
Mr Radich said "nothing other than a bit of maintenance has happened since 2015".
"This is an essential thing that needs to happen."
Council briefing papers said the project would "take 3-5 years to investigate, design and construct".
Cr Jim O’Malley was comfortable with the funding approach, because "a lot of the work would have been done anyway".
"We need to make sure South Dunedin is a safe place to live."
Although council staff stressed that none of the options would prevent wide-scale flooding in the area, they could at least mitigate it.
South Dunedin Future programme leader Jonathan Rowe agreed it would make a difference, particularly from an insurance perspective.
"If you have a flood that's a couple of centimetres below the floor level versus a couple of centimetres above, that can be the difference of $100,000 in a claim."
Cr Vandervis had reservations about the fact the project would be partly debt-funded, and called it an "election year" ruse.
He said a great deal had happened since the 2015 floods, including extensively overhauling the Portobello pumping station.
"Debt is our real problem, it’s not flooding in South Dunedin."
Cr Christine Garey voted in favour, but agreed with Cr Vandervis that much work had already been done, and there was a need to manage expectations.
Insurers are still counting the costs of last year’s South Dunedin floods in October, which ripped through dozens of properties.
Cr Andrew Whiley asked Mr Rowe whether any measure could prevent flooding outright.
Mr Rowe agreed the real question was about "levels of service".
"Over the next two years, we will talk about those trade-offs."
Council chief executive Sandy Graham said the council "upped its game" when responding to last year’s floods.
"It’s been honest, transparent and timely."
Mr Rowe also noted although the peaks were higher for the 2015 floods, the peaks lasted longer in last year’s flooding.
None of the proposed short-term measures would supercede the South Dunedin Futures programme, he said.
That programme’s report would produce seven possible climate scenarios for the area, all of which would require large-scale infrastructure upgrades.
The other approach staff suggested — which would cost nothing in the short term — was waiting for the South Dunedin Future adaptation plan to arrive, although staff noted this option meant flood risk reduction in South Dunedin would take longer to implement.
