A Piha park ranger says last night's torrential rain and flash flooding was the worst, and fastest, flood he has seen in 30 years on the job.
Roads were completely covered within half an hour, with cars swept along in the floodwaters, Auckland Council ranger Andy Peterson said.
A MetService weather station recorded 27.5mm of rain at Piha between 5pm and 6pm last night.
Another Waitakere weather station reported 43.5mm of rainfall in an hour.
A group of 20 people were trapped for three hours at Kitekite Falls near Piha yesterday. The falls are a short, easy walk from the carpark but a flash flood made the river impassable.
On Glenesk Rd, which leads to the falls carpark, about 100 people were evacuated from their homes.
Peterson told NZME it was "incredibly lucky" the tide had been out at the time, allowing the water to recede quickly.
Sixty people were evacuated by boat down the two-metre-high waters running down a Piha road yesterday evening.
The church group was taken from Piha Mill Camp, on Glen Esk Road, by the surf club's inflatable rescue boat.
Camp owner Peter Kruger said the water in the Kitekite Stream rose up within half an hour as high as his knees, and it was all gone again within another 40 minutes.
Mr Kruger says locals of 30 years have never seen the stream rise so quickly.
Piha's Deputy Fire Chief Ron Gorter said he was pushing floating cars off to the side of the road to allow the inflatable boat laden with evacuees down the street - or in this case, river - to safety.
A local for 25 years, Gorter says he's never seen the water rise so quickly.
He says the overflowing river rose one metre in 20 minutes.
A 150-metre stretch of Glen Esk Road was under two metres of water - up to the headlights of the fire truck trying to get through.
Gorter said the rain came down "really, really quickly".
"We got 10,000 litres in our water tank in half an hour, which is massive. It was a very intense weather pattern."
Kruger said the cleanup starts today after suffering significant cosmetic harm - but thankfully no buildings have any structural damage.
He says a few washing machines and dryers are gone, but the dormitories are completely unharmed.
The river is flowing calmly this morning but there is evidence of the floodwaters, with gravel and bush debris high on the riverbank and flax bushes sprawled across road signs.
The Piha community is now out in force beginning a tough clean up job.
An NZME reporter in the West Auckland village said there were tears, long faces and grimaces as neighbours checked on each other and offered hugs or a hand.
Some residents were counting their losses; others were thankful it wasn't any worse.
Cars are soaked through - doors flung open, seats still sodden. Many owners are too scared to try start them.
A lot have have grass and mud plastered across their lower panels - some with high-tide lines above their wheel arches.
Sunday for many Glen Esk Road residents is no longer a lazy day, but one spent with hands on hips, surveying the next job.
They're out with squeegees and brooms, mopping up and carrying dripping items at arms' length towards the growing pile at the side of the property.
Local Sharon Kelly said the volunteer spirit of locals - out on the street, offering a hand - is what the isolated community of Piha thrives on.
"It's wonderful. Everyone's here to help each other," she said.
I'm sure most communities are like that, but living here in Piha, we really notice it. It's fantastic."
Farther north in the Waitakere Ranges two people died last night after their group was swept away in a flash flood near Cascade Falls.
A third man was rescued by Westpac Rescue Helicopter.