Instead, the council is exploring other options such as diverting stormwater directly to the Portobello pump station, increasing the size of the Forbury Rd aqueduct, and disconnecting the Hillside Rd mains to redirect stormwater to the Orari St outfall through a new pump station. These measures could provide some relief while the city finalizes its climate adaptation plan in 2026.
The long-term strategy for addressing climate change and enhancing resilience is being developed through the South Dunedin Future program. However, specific adaptation options have not been selected yet, and implementation is not expected until 2027.
In the meantime, the council is considering a series of short-term measures to mitigate flood risk in South Dunedin. A report highlighted the area’s vulnerability to natural hazards and projected increased flooding risks due to climate change impacts.
Computer modelling was used to test nine options against a future scenario of a one-in-10-year rainfall event, showing that a detention pond at Forbury Park could reduce flooding volume by 21% and flooding area by 15%. However, the high cost associated with this option may be a deterrent.
Other options, such as a $25 million detention pond at Bathgate Park, were also considered. The council is exploring potential government funding sources, including a regional infrastructure fund that could partially finance projects like water detention at Bathgate and Forbury Parks.
A short-term package of measures costing $29.2 million was proposed, including diverting water from stormwater systems to the Portobello pump station, doubling the size of the Forbury Rd aqueduct, and pumping stormwater to the Orari St outfall.
Council staff presented two options for consideration by councillors – providing additional funding for short-term measures or waiting for the completion of the South Dunedin Future adaptation plan.
