The West Coast Regional Council has been warned by its auditor flood protection investment will need to increase under its proposed 2024-34 long-term plan because of the impact of climate risk predictions.
In reviewing the council’s 2024-34 LTP, the auditor flagged concerns about the level of investment proposed in flood protection assets administered by the council.
It did not reflect wider expectations by government agencies of the "impacts of climate risk" and the resulting need to increase flood protection spending across the region, auditor Brendon Summerfield told the council this week.
Council chief executive Darryl Lew said he took that to mean the "increased magnitude of flooding and aggradation" in river catchments, particularly in South Westland, and because of that special flood rating districts "should expect significant cost increases".
Mr Lew asked if it would be acceptable for rating districts to decide if they did not want to spend any more on assets, or to limit how much they rated themselves.
Mr Summerfield said that would be a matter of consultation with the relevant rating districts but any decisions would need to be based on relevant modelling.
However, Cr Allan Birchfield expressed scepticism at the climate risk argument.
"Climate change: it’s still debatable," he said.
"A lot of people do not agree with this ‘increased flooding’; give them the choice if they don’t believe it."
In the past 30 years, the scientific consensus is that humans are causing climate change, which will lead to more intense rain and flooding.
Scientific advice to the council in the past year has also cited the Interdecadal Pacific Oscillation (IPO) as a factor in climate variability on the West Coast, which is now into the long IPO period, which is characterised by more frequent and violent storms.
Cr Peter Ewen said the "increased flooding events" scenario was more nuanced, but the bottom line was what ratepayers could afford.
He suggested the issue was more increased gravel build-up in riverbeds impacting the effectiveness of flood protection banks.
"We have had these discussions with rating districts. It’s been not so much about getting the level of risk down but what they have in their pocket," Cr Ewen said.
Cr Brett Cummings said all rating district meetings in the past year had been asked "to up the money".
Some had agreed, others not.
Cr Andy Campbell, a farmer affected by the Wanganui River, said in his experience the biggest flood on that river was 40 years ago, and nothing like recent events affecting flood banks.
"The big thing is keeping our maintenance up."
Cr Campbell said the cost of maintaining river protection was the issue now.
"The price of rock has increased 50%."
Acting corporate services manager Aaron Prendergast said the matter needed a strategic approach to the rating districts.
"It’s not just your ratepayers but central government [funders] who have a view on that."
A business-as-usual approach to spending on flood protection assets risked a decrease in the level of service, he said.
Mr Summerfield said there were "difficult conversations to have" but rating district financing could not continue based on incremental spending increases.
"Inflation-based increases by default lead to a decrease in service."
- By Brendon McMahon
Local Democracy reporter
• LDR is local body journalism co-funded by RNZ and NZ On Air
