There were 357 flooding-related calls to the city council on Saturday and 76 until 5pm yesterday. Thunder and lightning struck the city last night.
Heavy rain hit other parts of the North Island yesterday and a tornado touched down in Raglan.
The Hemingways in Princess Rd were home on Saturday when part of their back lawn slipped away. Eleven-year-old son Jordan said: "Dad, there's a hole in the lawn."
Several metres of lawn in front of where they had just parked the car 10 minutes earlier was no longer there.
The family went to a relative's home for the night, but on returning yesterday morning were confronted with yet another large section of lawn missing.
The family gathered belongings and emptied their freezer over the weekend.
"Council engineers said that it would be best to vacate the house until Thursday because of the threat of heavy rain and the fear of more possible slips," Mr Hemingway told the Bay of Plenty Times.
"I have been told there is an 80-85 per cent chance that the house can be saved, but the engineers won't be able to tell us whether they can until they fully assess the damage, stabilise the slip area and dig out the transformer to repair it.
"At this stage it's unlikely we will be able to return to the house until Wednesday or Thursday," he said
Mr Hemingway said he and his wife had owned the 1970s property for six years and never had any flooding problems. The bad weather forecast prompted them to clear the guttering of leaves and other debris before the slip occurred.
Mr Hemingway was trying to remain positive the house would be saved.
"It's a very unfortunate start to the school holidays for my two sons for sure, but what else can you do but stay positive?"