Torrential rain in Christchurch overnight has now burst the banks of Christchurch's Avon and Heathcote Rivers.
The council says 30 to 50mm of rain has fallen across the city and a further 40 to 60mms are expected.
There's surface flooding in many city suburbs and the risk of slips on Banks Peninsula, with heavy rain warnings and watches in place for most of the South Island's east coast.
Kathryn speaks with Helen Beaumont, head of three waters for the Christchurch City Council and RNZ reporter Niva Chitook.