Key Takeaways
- The Kowhai River has burst its banks, causing serious flooding that has shut State Highway 1 between Ward (Marlborough) and Waipara (North Canterbury) and left many homes without power.
- A red heavy‑rain warning remains in effect for Marlborough and Canterbury (Ward to Hanmer Springs, southeast of the Awatere Valley, including the Kaikoura Range) until 6 am Wednesday, signalling a threat to life from flooding, river hazards and slips.
- Additional road closures include State Highway 63 from Kawatiri to Howard (West Coast) due to fallen trees, with NZTA issuing area‑wide warnings for winter driving conditions.
- Kaikōura’s wastewater system is overflowing as stormwater overwhelms the network; residents are advised to avoid contact with flood‑ or wastewater‑affected water.
- Road crews are applying grit and anti‑ice agents, and authorities urge motorists to drive to conditions, watch for ice build‑up, and expect further closures if weather worsens.
Flooding and River Breach
The Kowhai River has breached its banks amid intense rainfall, sending water spilling onto surrounding low‑lying areas and triggering serious flooding across Marlborough and North Canterbury. The deluge has inundated farmland, residential sections and key transport corridors, prompting emergency services to monitor river levels closely. Residents in the affected zones have reported rising water levels in streets and paddocks, with some properties isolated by flood‑water. The situation remains dynamic as additional rain continues to fall, increasing the risk of further inundation and potential damage to infrastructure.
State Highway 1 Closure
State Highway 1, the main artery linking the North and South Islands, is currently closed between Ward in Marlborough and Waipara in North Canterbury due to the flooding. The closure forces detours onto local roads, significantly lengthening travel times for freight and passenger vehicles. Abandoned cars line the shoulders of the highway where drivers attempted to proceed before the water became too deep, highlighting the hazards posed by the rapidly rising river. Transport authorities warn that the stretch may remain impassable until water recedes and the roadway is deemed safe for use.
Additional Road Closures and Warnings
Beyond SH 1, State Highway 63 from Kawatiri to Howard on the West Coast is closed because fallen trees have obstructed the carriageway between SH 6 and Howard Valley Road. The New Zealand Transport Agency (Waka Kotahi) has also issued multiple road‑area warnings across the central and lower South Island, citing prevailing winter driving conditions such as slick surfaces, reduced visibility and the potential for ice formation. Motorists are urged to exercise extra caution, reduce speed and adjust driving behaviour to match the deteriorating conditions.
Weather Forecast and Red Warning
MetService forecasts continued heavy rain and snow today, extending from inland Canterbury to the top of the South Island. A rare red heavy‑rain warning is active for Marlborough and Canterbury, covering the area between Ward and Hanmer Springs and southeast of the Awatere Valley, including the Kaikoura Range. This highest‑level warning indicates a significant threat to life from dangerous river conditions, widespread flooding, landslips and impassable roads. The warning remains in effect until 6 am on Wednesday, though further updates may be issued as the system evolves.
Power Outages and Infrastructure Impact
The flooding has disrupted electricity supplies to numerous homes near Kaikōura, with outages reported as water infiltrated substations and damaged lines. Utility crews are working to restore power, but access challenges caused by flooded roads and debris are slowing repairs. In addition to electricity, the inundation threatens other critical infrastructure such as telecommunications and water treatment facilities, prompting authorities to prioritize repairs that will restore essential services to affected communities.
Wastewater Overflows in Kaikōura
Kaikōura District Council confirmed that parts of its wastewater network have experienced overflow events due to the intense rainfall. Stormwater entered the system at volumes far exceeding normal capacity, leading to wastewater spilling into streets, paddocks and low‑lying areas in several locations. Council crews have been actively monitoring the network and are responding to overflow sites as conditions permit. As a precaution, residents are advised to avoid any contact with floodwater, ponded water or areas visibly affected by wastewater to reduce health risks.
Safety Advice and Precautions for Residents
Authorities stress that the public should stay away from flooded roads, riverbanks and low‑lying zones where water may be swift or conceal hidden hazards such as debris or submerged objects. Driving through floodwater is strongly discouraged; even shallow‑appearing water can conceal deep currents or wash away road surfaces. Residents are also encouraged to secure loose outdoor items, check on neighbours—particularly the elderly or those with mobility issues—and follow official updates from Civil Defence, MetService and local councils.
Ongoing Response and Mitigation Measures
Roading crews are deploying grit and anti‑ice agents on highways prone to ice build‑up, especially in higher‑elevation sections where melting snow may refreeze overnight. Teams are clearing fallen trees from SH 63 and assessing the structural integrity of bridges and culverts impacted by the flood. Emergency management centres remain on the South Island is coordinating sandbag distribution, welfare checks and potential evacuation centres should conditions deteriorate further.
Future Outlook and Continued Monitoring
MetService indicates that further heavy rain could develop later today, raising the likelihood of additional highway closures if river levels continue to rise or if slips render roads unsafe. Because of the combination of rainfall and melting snow, ice accumulation on road surfaces remains a concern over the coming days, particularly on shaded stretches and bridges. Authorities will continue to monitor weather forecasts, river gauges and road conditions, issuing updates and adjusting warnings as needed to protect public safety.
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