Angry residents at a seaside Bay of Plenty settlement are preparing for a fight over a move that would force more than 30 homes to be abandoned over a potential "loss of life".

The decision has proven a climax in the long-running saga over the fate of homes on the Awatarariki Fanhead at Matata, which was struck by devastating debris flows in 2005, leaving a mess of huge boulders and dead wood.

While Whakatane District Council tried to find an engineering solution to stop any future flows from some streams flowing from the steep escarpment catchments behind the town, plans to try to manage the risk for Awatarariki Stream were abandoned in 2012 on the back of expert advice.

The council investigated a "voluntary retreat package" and residents were made offers based on property valuations by a Tauranga-based firm that took into account past and current values and natural hazard risks.

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In May, the council decided to initiate a change to the District Plan which, if approved, would remove the current residential zoning and prevent any future development in the fanhead area.

While that plan change wouldn't have affected those already living there, most members of the council's policy committee meeting last month agreed that the risk of life was such that another plan change would need to be sought by the Bay of Plenty Regional Council.

This would mean existing use rights would be extinguished and affected residents would be forced to move.

The decision came despite pleas from property owners, who have been told a retreat package would be offered, dependent on financial support from the regional council and Government.

Upset residents were still discussing the next step forward, which could involve a court battle.

One local, Marilyn Pearce, doubted the support offered would be enough to start over.

She and husband Rob were granted consent to rebuild their home in 2007 following a decision from the then Department of Building and Housing.

Pearce rejected an offer on her property, which she said would have left her even worse off.

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"My value has halved but my rates are still going up - I'm paying $4000 a year."

Asked if she thought a legal fight was inevitable, she said: "To be honest I don't think we've really got a choice.

"For me, we either bend over and get shafted, or we fight them."

Pearce was also furious over what she saw as a lack of consultation or transparency by the council.

Committee chairwoman Judy Turner said the council had a moral obligation to take every possible step to reduce the risk applying to anyone living in the Awatarariki high risk area.

One previous report found the Awatarariki fanhead was a high-hazard zone with a person having a one in 10,000 chance or greater of being killed by a debris flow in any year.

It also stated, based on historical evidence and projected modelling, the fanhead was likely to be subject to future debris flow events.

"As difficult as it is, this is the right thing to do," Turner said.

"The Resource Management Act ensures that all stakeholders have a chance to have their views heard and, if anyone is not satisfied with the outcome, they are able to appeal the decision to the Environment Court."

The committee also agreed to add $250,000 to the 2017/18 Annual Plan to underwrite the cost of the private plan change process.

The move comes as researchers have begun investigating how some New Zealand communities could be pulled back from hazard zones in the face of flooding driven by climate change and sea level rise.

A new study, to be led by GNS Science as part of a near million-dollar wider research programme, will look at ways authorities and communities can plan for homes to be moved to safer ground.

It's estimated two thirds of Kiwis live in areas prone to flooding: at least 43,000 homes lie within 1.5m of the present average spring high tide, and nearly 9000 within 50cm.

Under current projections, sea levels could rise between 30cm and 1m this century.

While there were measures within the Resource Management Act that authorities could use to help plan for shifting homes or roads, the issue was fraught with complexity.

There were also conflicts between what actions regional and district councils could take, and private property rights also posed barriers for planners.