Queenstown is suffering twin crises, with a state of emergency issued for flooding and a boil water notice expected to last for months.
New Zealand's biggest tourist town was soaked by the biggest single-day rainfall in 24 years, with 87mm in the 24 hours to 9am on Friday.
More than 100 people were evacuated overnight after heavy rains caused "several flooding and debris events" according to Queenstown Lakes mayor Glyn Lewers.
Social media posts show streets overcome with mud, logs and forestry runoff from the nearby hill near the base of the Skyline Gondola.
Residents and tourists were advised to avoid the town centre with an evacuation centre set up at St Peters Church.
By mid-morning, the easing of rain allowed for a clean-up to begin in the CBD, and for businesses and people to return.
Elsewhere in the town, there are serious concerns for properties - with engineers assessing buildings hit by landslips - and access roads.
Queenstown's state of emergency call at 6.30am followed a similar declaration in the nearby town of Gore, and then the whole of Southland on Thursday due to the same weather system.
A slow-moving rain band dumped 102mm of rain on Gore, with dozens of volunteer firefighters and locals called in to place sandbags to save properties from flooding.
For much of the region, the rain was replaced by snow later on Friday, with snowfalls across Otago and Canterbury cutting off roads.
Mt Cook Village received 120mm in an unseasonally hefty dump.
A number of highways in the region are closed, though the road to Milford Sound which received 318mm on Thursday, has reopened.
While no injuries have been reported, further damage could follow.
Rivers in the region, including the Mataura River - a legendary waterway for brown trout fishing - is expected to peak later on Friday, with locals laying extensive sandbagging in anticipation.
The nearby Waikaia River burst its banks, affecting farmland.
The flooding and landslips follow an outbreak of parasite cryptosporidium in Queenstown, which the council is yet to bring under control.
At least 18 cases of the highly-infectious bug have been identified this week after complaints of stomach cramps and diarrhoea.
Social media posts suggest a more widespread problem.
While the origin of the outbreak is yet to be confirmed, public health authorities have issued the boil water notice as a precaution to protect further spread.
The national water regulator has issued a compliance order on Queenstown Lakes Council's Two Mile treatment plant for not having an appropriate parasite filter.
Mr Lewers said a fix that could see the regulator lift the boil water notice was still a way off.
"A best case (scenario) would be months ... to get the kit to here and install it, it could take some time," he said.
"We have to take a risk management approach."
Radio NZ reports local businesses are bringing in water from nearby lakes to keep their coffee machines running.
