Incoming heavy rain could be the biggest weather event locally since devastating floods nearly a year ago, Tasman District Council says, with a wash of weather and flood warnings on both the North and South Islands.

Heavy rain warnings have been issued for potential flooding and slips for various South Island regions, followed by warnings and watches for Taranaki, Northland and Bay of Plenty, with warnings lasting till Tuesday in some places.

MetService forecasters say the heavy rain could begin Sunday for northern and western parts of the South Island, from midnight into Monday at Taranaki, and from noon and 6pm on Monday for the Northland and Bay of Plenty, respectively.

Authorities in a number of regions have asked people to prepare for the storm, and for drivers to take extreme care on the roads as the long weekend winds up. In Marlborough the emergency management team has been activated.

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