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31 May 2021 | 05:39 AM UTC

New Zealand: State of emergency in Canterbury, South Island, May 31 due to heavy rain and flooding /update 2

Weather warnings remain in place for South Island, New Zealand, May 31. State of emergency in Canterbury.

Warning

Event

As of May 31, officials have declared a state of emergency in the Canterbury Region, South Island, following heavy rain and flooding. Authorities have evacuated at least 300 homes in Ashburton, Selwyn, Timaru, and Waimakariri. Widespread road closures are in place, and officials have urged residents to avoid nonessential road travel. More information about state highway access and road closures can be found here. Utility disruptions have affected at least 1000 homes in Christchurch. Information on active alerts in the Canterbury region can be found here.

Officials are maintaining several weather warnings for the South Island, including a red, heavy rain warning for Canterbury through May 31. For a full list of weather warnings, please click here. Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change.

Hazardous Conditions
Periods of heavy rainfall could trigger flash flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed or a lack of stormwater drainage systems. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where the soil has become saturated by heavy rainfall. Strong winds could down trees or powerlines, causing power outages.

Transport
Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters. The disruptive weather may cause some delays and cancellations at regional airports. Authorities may temporarily suspend port operations along the Tasman Sea and South Pacific Ocean if strong winds trigger hazardous sea conditions, impacting freight and passenger maritime traffic. Flooding could block regional rail lines; freight cancellations are possible in areas that see heavy rainfall and potential track blockages.

Disruptions triggered by inclement weather and resultant hazards, such as flooding, could persist well after conditions have improved - it could take days before any floodwaters recede and/or officials clear debris. If there is severe damage to infrastructure, repair or reconstruction efforts may result in residual disruptions.

Advice

Monitor local media for weather updates and related advisories. Confirm all transport reservations and business appointments before travel. Make allowances for localized travel delays and potential supply chain disruptions where flooding has been forecast. Do not drive on flooded roads. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

MetService