The council has been monitoring the northern end of the wall, near Broad Bay on Otago Peninsula, since heavy rain last July caused existing cracks to worsen, council transport delivery manager Josh Von Pein said.
Temporary work, including installing safety barriers and reducing the road to one lane, had already been carried out and surveying was being carried out to design permanent repairs, he said.
It was not yet known when the repairs would be carried out, or the likely cost, or whether the new cracks were part of the same slip that led to the construction of the retaining wall, he said.
However, extending the retaining wall would be one option considered for a permanent fix.
Construction of the existing wall began in January 2015, after a storm in June 2013 caused slips affecting 200m of Portobello Rd above Turnbulls Bay. The wall was originally due to be completed by May 2015, at a cost of $1.51million, but the timeline and bill blew out after contractors struck unfavourable ground conditions.
It was eventually completed in February 2016 at a cost of $2.8million.
