"All of a sudden we looked up to see all this water just flooding towards us. It was so fast - it carried down logs and just flashed the whole ground in about two minutes.
"It just happened so fast, we literally just picked ourselves up and got out."
Gideon Hope, 16, said they had just finished afternoon devotion when the waters started flooding into the hall he was in.
"The water just came in, we couldn't do anything about it.
"It was a bit scary," he said.
Others said the water reached their ankles.
Later this evening a police spokesperson said the flooding looked to be receding and, if it continued to do so, police hoped to allow people back into their homes within a couple of hours.
Phil Wallis from the Piha Surf School said "soaking wet, barefoot" people were being let back into their homes at about 8pm.
He said the floodwaters had receded though there were still "big pools of water" around the street.
Wallis' friends had water come through their garage and into a car.
He said he was in the water taking a lesson when the rain started.
"It was horizontal . . . in almost 40 years here it's the strongest rain in a short period I've seen. You couldn't see the beach.
"Immediately the stream stuff started just pumping out brown water."
A nearby stream which usually didn't have any flowing water when there had been little rain transformed into a "torrent".
"It was almost a standing wave coming down the beach."
Earlier on, Fire and Emergency northern shift communications manager Scott Osmond said people were being evacuated from Glenesk Rd.
"Five or six houses are at risk of flooding, so we're evacuating as a precaution."
Osmond said water levels in a nearby creek were rising, due to the heavy rain.
The Piha Surf Lifesaving Club were among those to help following the flooding; with members being called out to help residents whose vehicles had become stranded as a result of flooding waters.
A number of residents were brought back to the club for a short time, where they got to have a meal and a cup of tea before heading back home.
Club president Peter Brown said: "We've has flooding at Piha before, but not of this intensity.
"It was just really a very short 30 minute huge amount of heavy rain."
Piha resident Bevan Hill said the local art gallery was flooded as well as the campground.
"There's a lot of people there saying they've never seen anything like it before.
"The river coming out on Piha beach is incredible. It's like the Waikato River flowing out there."
Hill said there was "water everywhere" and he had water coming in his front door on Garden Rd earlier, but was now safe.
There were "a lot of wet and soggy campers" packing items into their cars, and a few tents had ended up underwater.
"It all happened so quickly, too."
A worker at the Piha Surf Shop, which is elevated, said they could see "a lot'' of water down below, following a sudden extreme period of heavy rain this afternoon.
"The flooding is in the valley. My son said there is water over the road at the fire station and the road has been cut off.''
The Piha Fire Station is on Seaview Rd, near Glenesk Rd.
Talking about the weather, the woman said they had had some warning just before conditions turned "extreme".
Debbie Leigh from the Piha RSA said people were reporting cars drifting in the flood waters.
Wallis said friends of his had taken pictures of cars floating in floodwaters, with the water rising up to the sills inside the cars.
A number of people who were walking in the bush on Winstone Track off Piha Rd
called police at 5.15pm concerned they were trapped by rising river levels.
The group of approximately 20 people included people from various groups who
had been walking in the bush through the afternoon and banded together to get
out safely.
They have since found a safe route back out of the bush and were walking out towards Glenesk Rd.
