People still in their homes in flooded parts of Christchurch along the Heathcote River are being told to stay put for the night.
The river broke its banks in the torrential rain, with water covering the neighbouring streets in the suburbs of Beckenham, St Martins and Opawa.
The council had earlier advised people in the lowest areas next to the Heathcote to evacuate their homes, but as high tide drew near, just after 3pm, they were advised to stay put if the flood water was above knee high.
Attention was now turning to the next high tide, at about 3am.
People still in their homes have been advised to stay there, as it would be too dangerous to try and get out in the dark.
Those who did evacuate have been told they should not try to return overnight.
Christchurch civil defence controller Mary Richardson said the water supply was safe to drink, but people should try to keep their waste water to a minimum as the system was already overloaded.
The council said the Coastguard response teams could help people out of their homes if needed.
The Coastguard said the vessel was equipped with emergency lighting, wetsuits and first aid supplies, and the crew could continue evacuations into the evening if required.
The army was also now providing assistance in Christchurch.
A welfare centre has been set up at Linwood College for evacuees.
Emergency work has also been undertaken on the banks of the estuary in Southshore.
The council said three of four low areas had been filled, but that contractors were unlikely to completed the final area before high tide earlier this afternoon and water was likely to come through.
The council says pumps have also been put in place in Southshore to help manage the water.
Christchurch Mayor Lianne Dalziel said Heathcote would be a top priority once the flood recovery swings into action.
Ms Dalziel said stormwater retention in Heathcote had been done, but it overflowed in the heavy rain.
The Minister for Civil Defence said the focus across affected parts of the South Island was now on the response effort - clearing roads, rail and getting people back on their feet.
Nathan Guy flew over the flooded plains of Taieri and spoke with local farmers, who said there was likely to be debris from forestry slash.
He said it would take some time to get tractors to the affected areas to clear stockpiles of feed.
Mr Guy said it came at an unfortunate time for farmers, with the beginning of calving and lambing just around the corner
Key points
- The Heathcote River burst its banks in south Christchurch and wastewater has been flowing into some streets, and the city has declared a state of emergency as a precaution
- The lower parts of Dunedin airport were flooded by about half a metre of water
- Dozens of roads around Dunedin have closed. A large slip close to King George Street means access to Portobello and Broad Bay has been cut off
- Access to Milton was closed with State Highway 1 both south and north of the town blocked by floodwaters
- Authorities are warning people to stay off the roads in Otago-Southland if they can, saying they had run out of 'Flooding' signs
- Flood levels at Outram were the second-highest ever recorded for the Taieri River today
- A large slip forced a number of houses to be evacuated Ravenswood Street in St Clair
Otago flooding fears begin to ebb
Otago Civil Defence said rain in the region has eased and rivers are beginning to recede. In Dunedin, waterways were receding with the exception of the Taieri, which was still fluctuating at high levels.
The Taieri River was expected to remain high regardless of whether more rainfall occurs, but houses and cribs at the township of Taieri Mouth have been spared after the river peaked below them.
Sandbags and rocks have been used to plug most of a hole that was letting water back under the pumphouse at pressure from the Taieri into Mill Creek.
There are widespread road closures in Dunedin due to flooding and slips.
In Waitaki, there was widespread flooding over many parts of the district and there was some sewage leakage in the Oamaru township.
Some local roads were closed and there was damage to some properties.
In Central Otago, river levels were receding and weather forecasts showed the rain was clearing, but there were widespread road closures in the Maniototo and Ida Valley, and damage to roads.
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Snow was falling, affecting roads with some closures remaining in place overnight.
Sub-zero temperatures overnight in Canterbury and Otago were likely to causing hazardous driving conditions on many routes from about 4am onwards.
Transport Agency and council roading crews will be out applying grit, so drivers needed to take care on gritted roads as well as icy road.
It was not yet clear whether schools in Otago will open on Monday.
There were about 25 slips on roads across the city, many of them on the Otago Peninsula.
Ravenswood Street in St Clair was closed and 12 houses have been evacuated due to a slip there.
Another slip in Harington Point Road was still shifting and work to clear it will not start until Monday, leaving Otago Peninsula residents north of Harwood cut off.
Otakou marae is door-knocking in the area and providing welfare to those who need it.
About 100 households in Outram near Dunedin were evacuated overnight, plus about 120 more across the region, as the Taieri River continued to rise.
Flood levels at Outram were the second-highest ever recorded for the Taieri River, which was expected to peak about 1pm.
Taieri Floodgates opened at a riverflow of 100 cubic metres per second, but flows at 8am had reached 1985 cubic metre per second.
People were initially asked to go to emergency centres set up within the town, but about two hours later people at those centres were urged to leave.
An army Unimog was shuttling people from Outram to an emergency centre in Mosgiel.
Residents in North Oamaru spent the day cleaning out garages, basements, and even houses after yesterday's deluge inundated the town's stormwater network.
A record amount of rain fell in the Waitaki district yesterday, forcing people to evacuate their homes. In less than an hour, Walbrook Crescent went from being a wet street to two feet under water.
That contaminated water forced an elderly couple out of their house when it flooded yesterday afternoon. The neighbour said contractors only started putting sandbags around it after the water had started receding.
In other parts of Oamaru, the only visible reminder of the flooding was the debris washed up driveways, fences, and near the doors of business.
And the Humber Street bridge was closed, after the overflowing creek ripped a hole in the tarmac.
Military aid
Early this morning, the Army assisted Civil Defence in rescuing nine people trapped in and on cars on State Highway 87 - the route from Maniototo to Dunedin.
A unimog transported the occupants to safety.
Troops reassigned from a planned exercise to help with flood relief in Otago and Canterbury are also being helped by a regiment from Scotland.
The Scots were due to join a battalion from the Royal New Zealand Infantry Regiment in a 26 kilometre race around Dunedin's surrounding hills.
Brigadier Mike Shapland said about 200 troops were now working with Civil Defence authorities.
Brigadier Shapland said five Army trucks left Timaru earlier today to patrol flooded communities in South Canterbury.
Flooding hits low-lying airport buildings
Taieri river sits alongside Dunedin Airport and chief executive Richard Roberts some low-lying buildings were flooded.
"We've got some buildings with kind of half a metre of water through them in the lower parts of the airport
"We've got a hangar, an engineering workshop that's got water through it as well, there's some rental car garages have got water through them."
He said the terminal and runway were not affected because they are higher up.
Farmers cleared for effluent release
Dairy farmers in Otago are being allowed to release small amounts of effluent where storage ponds are at capacity because of the heavy rain.
The regional council said many farmers have expressed concern about how to manage them.
The council said if possible farmers should get a truck in to pump out effluent.
However, it said because these were exceptional circumstances farmers can release some effluent, but only as little as possible.
It warned that it was not permission to release entire ponds.