"There was flood water up to our waist."
Teachers had to piggy-back pupils out of the school as the water was too deep.
"The last child left two hours after we first called the Ministry to close the school.
"It happened so quickly," she said.
While she wasn't clear if there was any water damage in the school building, consultants would come assess the damage tomorrow.
The school was also affected by flooding last May.
Teacher Maz Holman said last year's flooding was much worse as the front classroom blocks were flooded.
"Last year it came all through the front classroom block and all students were off-site for a week and a half."
One of the worst affected areas was Porirua's Warspite Ave, where part of the road was closed.
Resident Francis Campkin said in his 43 years of living at his house, today's flooding was among the worst.
"This happens a couple of times a year but that's definitely the deepest one I've seen. It even washed onto the steps on our front gate earlier this morning."
Mr Campkin installed drains outside his house 10 years ago to stop the water getting near his home.
The Fire Service was kept busy yesterday as it attended more than 50 callouts between 9am and midday.
Two marae in Porirua opened their doors to anyone who couldn't make it home.
One of the organisers at Horouta Marae, Pania Houkamau-Ngaheu, said about 30 people visited the marae throughout the day.
She said it was a dry and warm place with food that people could come to while they wait to go home.
People who visited the marae have told her the water rose rapidly in the morning.
"Looking out the window, one minute it was dry and the next minute there were ducks floating down the street.
"Others were shouting out to neighbours to stay inside. Some were really worried about their children, especially at Porirua School, they couldn't get out of their own home to get their children."
The other welfare centre was at Titahi Bay School.
MetService meteorologist Claire Flynn said nearby Wellington suburb Tawa recorded 68.2mm of rainfall this morning.
She said the rainfall was heavy, but it was made more significant as Wellington hadn't had much rain recently.
Last month, 34mm of rain was recorded for Wellington suburb Kelburn, but this morning alone 32.2mm of rainfall was recorded.
"So in one morning, it equalled last month's rainfall."
MetService meteorologist Mariken van Laanen said tomorrow's weather would be dry.
"There is morning cloud and that breaks up and will get sunny spells for the rest of the day."
The rainfall would be easing as it moved north.
"We are expecting some scattered rain and drizzle in the central North Island."
During a flood
• Make sure you, your family and pets are safe and in a dry area
• Do not attempt to inspect or repair any damage until it is safe to do so
• If the floors are wet, lift your furniture off the floor to prevent staining
• Keep your damaged items if they are safe to do so, or take photos -- this is useful to confirm what needs replacing
• Don't drive unless you absolutely need to. If you vehicle has been damaged or suffered flooding it may be unsafe to drive