Christchurch City Council has issued an emergency evacuation order after the city was declared in a state of emergency following wild wet weather.
The call comes as Heathcote River burst on Saturday morning due to rising flood waters after torrential rainfall hit the South Island overnight. The New Zealand Defence Force is also assisting local authorities.
More than 1,500 people across the region were forced to evacuate their homes according to local media, with more than 100 homes evacuated in Dunedin.
Christchurch is the fourth region in the South Island to be declared in state of emergency following ongoing recovery efforts in Dunedin, Timaru and Otago.
New Zealand Defence Force's Kendall Langston told Sky News Australia the troops are supporting police and the public navigate the flood waters.
— Sky News Australia (@SkyNewsAust) July 22, 2017
Reports indicate some areas within the South Island received more than 200mm of rain in just 24 hours -- double the average rainfall for July.
New Zealand Prime Minister Bill English has expressed his support for those affected by the floods.
My thoughts are with those affected by the weather events in the South Island. Please follow official advice and take care of each other.— Bill English (@pmbillenglish) July 22, 2017
There are reports people have been rescued after becoming trapped in cars in flood waters. No fatalities have been reported.
ALSO ON HUFFPOST AUSTRALIA