About 100 residents in the Selwyn Huts in Canterbury were earlier this evening encouraged to evacuate as rivers around them continue rising

Heavy rainfall in the Selwyn river catchment means river levels are expected to continue rising overnight.

This may cause flooding in the lower Selwyn catchment and across Days Road, and other roads may also become impassable.

A Civil Defence Centre is open at Lincoln Event Centre, on Meijer Drive in Lincoln.

Labour List MP Dan Rosewarne says people should check in on their neighbours, if it's safe to do so.

He says it's important to check people are okay and have supplies - and perhaps help them evacuate, if they have mobility issues or don't have a car.

Multiple roads in Canterbury are closed because of flooding.

Heavy downpours have forced the closure of State Highway 1 at the Ashburton River/Hakatere Bridge at Ashburton until at least 6 in the morning.

This is because of debris building up in hazardous fashion on the bridge pylons.

The Wamakariri District Council has asked residents in Tuahiwi to evacuate.

Flooding has also forced the closure of State Highway 77 in Mid Canterbury, between Thompsons Track and Pole Road.