Kaikōura District Council has declared a state of emergency as bad weather continues to hammer the upper South Island.
The council said the Kowhai River breached its banks about 10.26am, and that people would need to evacuate to higher ground.
Civil Defence urged people to evacuate immediately if they are on the Kaikōura fan between Middle Ford and the township or low-lying area properties on Beach Road, Ludstone Road, Greys Lane, West End, or if they had a property that flooded in 1993. The agency said people needed to go go higher ground and stay with family or friends.
Emergency services have already been assisting with evacuations across the district.
The New Life Church is open for shelter on Beach Rd and is the new evacuation centre after the car park at the Takahanga Marae filled up. The marae is still available for welfare and shelter.
The weather has knocked out power to dozens of people, and it could take several days before it is restored.
A MainPower spokesperson said they were "closely monitoring and will commence repairs when it is safe to do so".
An outage on the Inland Rd in Kaikōura affecting 44 customers was expected to take several days to restore due to the severity of the damage.
Nearby, the Hurunui District Council said it was ready to open an emergency operations centre if weather conditions deteriorate.
District mayor Marie Black said the northern parts of the district, including Hanmer Springs, Waiau and around Cheviot, appeared to be the most affected.
Drivers were earlier being warned of the potential for travel disruptions and road closures in the region today.
A red heavy rain warning remains in place until early tomorrow morning for Marlborough and Canterbury between Ward and Hanmer and southeast of the Awatere Valley, including the Kaikōura ranges.
Orange heavy rain warnings are also in place for Marlborough about and north of Blenheim, and Tasman District about and west of Motueka.
St John was called to the scene about 3.30am and said firefighters were working to rescue the person.
In an update just before 8am fire officials said the occupant was rescued about 7am.
Their Specialist Water Rescue Team members then responded to a two-vehicle crash on the Inland Kaikoura Road which left two people seriously hurt.
The people were trapped in vehicles by flooding near the Cribb Creek Bridge, as the creek had overflowed.
In an update just before 9am police advised the the Inland Kaikoura Road was now closed.
"Cribb Creek has burst its banks and Cribb Creek Bridge is unsafe to drive along.
"Stay home if it's not necessary to travel."
Elsewhere, the wild weather has closed several highways, including SH1 from Waipara in Canterbury to Ward in Marlborough, and NZ Transport Agency Waka Kotahi (NZTA) says further disruption is expected today. SH1 is expected to remain closed overnight.
Amid the bad weather, the Kaikōura District Council urges people to postpone travel plans to the area.
The district is under a red level rain warning and it’s expected to last for 36 to 48 hours bringing 250 up to 600mm of rain, primarily to the Inland Range.
The council says its Civil Defence team has been working since Sunday afternoon to understand the potential impacts as well as doing all possible advance mitigation.
It warned of rising waterways, slippery road conditions, surface flooding and slips.
"If you see rising water, act immediately and move to higher ground. Floodwater can carry debris.
"We ask you to take care, do not travel unless it is strictly necessary and take care on roads at all times. Please reconsider postponing your travel plans for 48 hours during these school holidays."
NZTA says road users should drive to the conditions, expect weather hazards, and be prepared for road closures at short notice. With bad weather also affecting North Canterbury and the West Coast, travel in these regions may also be affected.
