Dunedin City Council is warning people not to try to return to the flooded settlement of Henley until flood waters recede.
35 homes in the settlement on the bank of the Taieri River were evacuated late on Friday night when the river rose to its second-highest level on record.
Dunedin City Council flood recovery manager Simon Pickford said a flyover had been completed and and Henley had been badly affected.
He said some people were already back in their homes, but he would encourage others not to try to return for a few days because there is a significant health risk.
The council had been contacting people to find out the full impact of the flood, with four homes so far given dangerous building notices.
Mr Pickford said there were probably more that were damaged.
The Otago Regional Council said the final repair bill from the weekend's flood would be substantial.
Council chair Stephen Woodhead said the full picture of the damage was not yet clear, but there was significant damage to roads.
He said some bridges, including the historic Sutton suspension bridge in Middlemarch, had been wiped out.
There are also dozens of slips affecting private property and roads, especially on the Otago Peninsula.
