And the worst is far from over with MetService warning more wet weather is in store for coming days.
This morning, 200 children from Stanley Bay Primary School on Auckland's North Shore, and Mangatawhiri School, were rescued in a massive emergency evacuation as waist-deep water inundated Camp Adair at the foot of the Hunua Ranges.
A second evacuation is under way at the Hunua Falls Camp, where a further 150 children were trapped in the grounds by a falling tree.
The Auckland Council says flooding and slips have cut off a number of roads in the region, and Auckland Transport contractors are now assessing the damage. At least one property has been evacuated and many are trapped in their homes.
Severe flooding has also hit the Coromandel Peninsula, where roads across the peninsula are impassable.
Thames-Coromandel District Council said flooding has affected Hikuai, Pauanui, Opoutere and Whangamata.
Listen to Newstalk ZB for the latest updates
Scores of properties in Papakura, Kawakawa Bay, Beachlands and Maraetai have been affected by floodwaters.
Kawakawa Bay Store and Takeaways manager Yougesh Patel said flooding in the seaside town east of Auckland wasn't too bad, but people were unable to get in or out.
He said the road west to Clevedon was partially flooded, and the polo grounds near Clevedon were completely flooded.
About 900 households in Takanini, Whitford and Clevedon are without power.
Auckland Council emergency operations head Adam Davis said many properties in the Papakura, Kawakawa Bay, Beachlands and Maraetai were directly affected by flooding and local roads may be closed or affected by slips.
Severe inland flooding has closed roads in Papakura and Clevedon. The Fire Service and Auckland Council stormwater services are in the area, and at least one property has been evacuated with assistance of fire service.
At Kawakawa Bay 15 homes had been affected by flooding and slips on Turei Hill are preventing people getting out of of the bay. The Fire Service was door knocking to ensure residents were safe.
"Emergency services will continue to support those directly affected and we should see rain easing in the next few hours and flood waters starting to recede," said Davis.
"We're asking people to be patient and sensible. Roads are closed due to slips, conditions are messy and slippery, and areas are flooded.
"Attempting to drive through floodwaters can be disastrous for vehicles and requires emergency services to rescue people - we don't want to see any more of this happening."
Motorists have been asked not to travel in flooded areas until the water has receded.
MetService duty forecaster Cameron Coutts said heavy rain has fallen across Coromandel, Auckland and Northland since yesterday.
Up to 36mm an hour fell across eastern Auckland, resulting in localised flooding.
An enormous 161mm had fallen in Waiheke Island, causing slips across roads and flooding.
Onetangi Straight, Blackpool, Waiheke Rd, Wilma Rd, Te Toki Rd, Goodwin Ave. Matiatia, Awaroa and Waiheke Primary School are flooded and there are slips Wharf Rd, Oceanview Rd between Burrell Rd and Little O, 30 Junction Rd and 7th Ave.
Power is also out in some areas.
Further north, 116mm has fallen in Whangaparaoa since yesterday.
Heavy rain is expected to ease over the morning and floodwaters should recede throughout the day. More rain is expected later in the week but at much lower intensities.
Do you need help:
If you need emergency assistance, phone 111.
in Auckland, for flooding and stormwater issues and tree damage on public land, call the council on (09) 301 0101.