Sea level rise 'still an hypothesis' says West Coast iwi leader

West Coast leaders have called for more detailed information backing an updated coastal hazards rule for the region after submitters overwhelmingly opposed it.

During the debate, one iwi council leader said sea level rise was "still a hypothesis" and long-term local monitoring showed "no evidence" it was occurring there yet.

The new Coastal Hazard rule variation, under the West Coast's proposed new district plan, would impact future coastal building development permissions and possibly their insurability.

A debate ensued at the Te Tai O Poutini Plan (TTPP) meeting on February 14 on the proposed variation.

Haast ratepayer Vance Boyd in the public forum challenged the variation being based on a 1:100-year inundation period and wanted "the best possible science" informing new planning rules affecting his property.

Boyd said the variation consultation was "rushed" and some ratepayers had missed out.

He believed 1:25 and 1:50 year settings provided in the original NIWA data should also be included.

At the same time, Alpine Fault earthquake impact risk affecting coastal areas needed to be acknowledged given the "higher probability" of that within 100 years, he said.

TTPP council and Iwi representatives voted unanimously to hear directly from the scientists involved — likely within a workshop in April.

Boyd said the proposed variation seemed premature and unfair to TTPP submitters.

"If it goes before a hearing, it forces the onus of proof back on the submitters, and they would then have to hire legal representation," he said.

West Coast Regional Council chair Peter Haddock said the new maps gave much clarity but there were also "some discrepancies". The spectre of legal challenge in pressing ahead with the variation was real, given the hearing process schedule.

Westland Mayor Helen Lash said the cost to the TTPP in delaying should not be a justification "to plough ahead".

Te Runanga o Makaawhio chairman Paul Madgwick said other areas such as Hokitika were "in deep trouble" if erosion was the yardstick for coastal hazard areas.

Hannahs Clearing was a case to reinvestigate rather than taking "a broad brush view".

"This is not to minimise the severity of what we face, and the problems up north with [Cyclone] Gabrielle … but we need the opportunity to get it right. What if the new Government comes to the councils that it will be more sensible to adopt a 50-year time frame?"

Boyd said the coastline at his Hannahs Clearing property barely changed between 2007 and Cyclone Fehi, in 2018.

That trend was also in line with aerial evidence going back over 70 years and three big weather events and King Tides after 2018 had had negligible effect.

He did not believe ascribing those events as a "severe coastal" inundation risk could be justified, Boyd said.

Madgwick said the ebb and flow of marginal beach erosion referred to by Boyd was "typical" of South Westland.

To speak of it as erosion was one thing, but to attribute that to projected sea level rise was another.

Sea level rise was "still a hypothesis" in his mind, and he noted long-term monitoring at Jackson Bay showed "no evidence" it was occurring there yet, Madgwick said.

"Until we see evidence that in actual fact it's not the case, and we're going to see horrendous rise, I agree," he said

Buller Mayor Jamie Cleine asked whether the insurance sector had changed its approach, noting the implications for Westport.

Boyd said "no special loading" onto insurance premiums had emerged yet for Hannahs Clearing.

However, Lash said the insurance sector was watching closely how the TTPP proceeded.

West Coast Regional Council chief executive Darryl Lew strongly advised caution.

NIWA had provided "the right science" for the TTPP but it was "one of the most difficult and fundamental decisions" for the TTPP Committee.

The after-effect of Cyclone Gabrielle continued to press on disallowing further development in coastal hazard areas and councils had a responsibility to act on that in line with national policy, he said.

By Brendon McMahon, Local Democracy Reporter

LDR is local body journalism co-funded by RNZ and NZ On Air