A MetService meteorologist says enough rain has fallen in Fiordland over the last 24 hours to fill 800,000 Olympic-sized swimming pools, as the West Coast takes a battering today.
An Emergency Coordination Centre at the West Coast Regional Council has been set up with full staff to monitor the large weather system moving throughout the region.
The cold front currently moving up the country has mixed with warm air to produce what MetService meteorologist Lisa Murray calls a "significant" amount of rain.
"Even by West Coast standards, this is a really significant event," Ms Murray told 1 NEWS. "There is 500 to 700 millimetres of rain expected in the West Coast ranges.
"That's significant seeing as we put out severe weather warnings for 100 millimetres of rain in 24 hours, so there's quite a bit more than that."
The rain has seen the closure of State Highway 6 from Hokitika to Makarora closed due to slips, and South Westland Area School has also been closed for the day.
Ms Murray talked about some of the huge numbers coming from the front.
"If we look at Milford Sound, for instance, the station there recorded a one-in-20-year event, so it's quite a substantial amount of rain already and there are huts and DOC sites in that region that recorded 300 millimetres in a day.
"The amount of rainfall recorded in Fiordland already could fill 800,000 Olympic sized swimming pools," she said.
And there is still a lot of rain yet to fall in the West Coast, according to Ms Murray.
"For the West Coast, the worst of this rain will be up until midnight tonight, although it does last until tomorrow morning when warnings will be lifted."