'We're a bit worried': Emergency workers assess damage on Banks Peninsula

Flooding on State Highway 75. Photo: Caleb Clayton / Supplied

A helicopter is flying over Banks Peninsula so emergency workers can assess slips from the rain that has pummelled the area.

A fallen tree on Gebbies Pass Rd. Photo: Supplied

States of emergency remain in place on Banks Peninsula, and in Selwyn and Christchurch.

Banks Peninsula saw more than 200mm of rain in 48 hours.

Mayor Phil Mauger said Christchurch City Council is particularly concerned about the damage to Lighthouse Rd in Akaroa.

"We're a bit worried - there's a crack in the road about a good 100m long, 50mm wide, but it's definitely - something's going to move.

"It's not if, it's when, so we've got to look at that and keep going."

Three homes in Akaroa and one in Lyttelton have been evacuated as a precaution because of nearby slips, and a slip has also closed Dyers Rd in Christchurch.

"Very quiet night as far as rain goes," Mauger said.

"Thank goodness it stopped raining, because we've got at the top end of the Heathcote River, we've got some massive, retention basins that hold over a million cubic meters of water.

"They did not need one more drop in them because they're full."

Mauger said the city was "a little bit ahead of the eight ball" when it came to managed retreat as the earthquakes forced their hand early.

"We're 200m back from the river in most places."