Photo: RNZ/Maia Ingoe
West Coast Civil Defence Group Controller Te Aroha Cook says people should not become complacent about the lull between the two weather fronts moving over the region.
MetService said between 200 to 350 millimetres of rain had already fallen on the West Coast since 10am Tuesday but warned more was on the way.
The region is currently under an orange heavy rain warning with up to 800 millimetres of downpours expected by Thursday night.
Power could be out for several days to some customers after sea conditions downed several poles.
While there is currently a lull in the intense showers, more of the deluge will be pushed back towards the West Coast from the Tasman Sea later on Wednesday night.
Meanwhile, personnel from Civil Defence, Fire and Emergency and rescue teams had come over from Canterbury to assist the communities in Ōkārito, Franz Josef, and Whataroa in case of evacuations and to help with sand-bagging.
Civil Defence estimated, as of Tuesday night, there were about 600-700 tourists in Franz Josef, but believed many had headed back via Arthur's Pass or Lewis Pass.
RNZ is New Zealand's statutory civil defence lifeline radio broadcaster, providing vital information and updates as they come to hand.
Check out the frequencies here.
The National Emergency Management Agency (NEMA) advises that in times of crisis or civil defence emergency a battery-powered radio or a car radio remain essential lifelines if power is out and other forms of communication are unavailable.
Follow Wednesday's weather updates with RNZ's blog: