Christchurch's Mayor is backing her decision to declare a state of emergency ahead of ex-cyclone Gita and is renewing calls for the Government to implement an option to declare such events "serious incidents" instead.

Lianne Dalziel made the decision to lift the state of emergency at 11am after high tide passed without incident.

The state of emergency was issued for the area shortly after 4pm yesterday, as ex-cyclone Gita began to bear down on the country.

Christchurch received about half the rain anticipated and there were no reports of flooding above floor level.

Wednesday, 11am:

Christchurch Mayor Lianne Dalziel has lifted the state of local emergency.

The decision was made at 11am after the high tide passed with no major flooding issues in the city.

However, water remains on several roads and motorists are advised to take care.

— ChCh City Council (@ChristchurchCC) February 20, 2018

Shortly after, Dalziel told the Herald it was the right thing to do.

She would make the same call in the future, she said, however hoped more options would soon be made available.

"I look forward to the Government considering the recommendation to create an option to call a serious incident rather than a state of emergency," she said.

The recommendation was one of several outlined in a ministerial review into emergency management released by Minister for Civil Defence Kris Faafoi and authored by technical advisory group chair Roger Sowry.

The recommendation was that Faafoi "provide the option of the mayor declaring a 'major incident'."

"Declaring a major incident would likely result in activation of an emergency operation centre, increased social media profile, liaison and co-ordination with emergency services and use of powers available to councils, Fire and Emergency NZ, the Police, and others, under other Acts," the report stated.

Examples of when a "major incident" might have been declared included the potential flooding of Whanganui in April last year, and the Hawke's Bay gastro outbreak of 2017.

Some residents evacuated from their homes in Clarendon Terrace, Christchurch, as the river levels rose due to rain from ex-tropical cyclone Gita. (Photo / Newstalk ZB)

Selwyn District Mayor Sam Broughton agreed having the option of declaring a "major incident" while underway as opposed to declaring a full state of emergency, was one worth exploring.

With the system as it stood, Broughton likewise backed the decision to declare a state of emergency yesterday afternoon, ahead of ex-cyclone Gita.

"Throughout the day on Tuesday we were presented with data and forecasts that consistently indicated extremely high levels of rainfall, particularly in the foothills of the district which are the key catchment of our river systems," he said.

Broughton said the flooding that hit the area last July meant authorities knew they could be faced with a need to evacuate low-lying areas.

"Declaration meant that we had access to powers and resources that would make that process much easier and smoother to facilitate, and we were able to place other agencies on standby to assist."

Buller District Mayor Garry Howard said if there was a threat to local residents' safety and homes, he didn't know why the mayor of any district would not declare.

"It gives us access to resources we wouldn't otherwise have."

Howard said he was aware there was often opposition to whichever choice Council went with.

"You're damned if you do, and you're damned if you don't."

A local state of emergency remained in place for New Plymouth District and a handful of South Island regions.