"The shoulders of roads are dangerous. There's rubble about and there is still in places water on the roads, so people will need to be very, very careful driving."
It would be "costly" to fix the damage, Mr Familton told Radio New Zealand.
"I've seen some of the roads this morning and the water runoffs have caused a lot of damage - there's culverts that are blocked."
State Highways 82 and 83 were still closed, he said.
Some rural residents were still cut off by flooded rivers.
"That is not serious and water levels are receding very quickly - in fact it's quite a pleasant day forming here.
"I can see today as a day where we'll regain our shape somewhat, but we still have to be somewhat wary because there'll be a cold break coming through later on tomorrow, which won't help the situation at all," Mr Familton said.
