Soil moisture lower than normal nationwide, increasing fire risk

Tuesday, 7 January 2020

It's not even summer yet but hoses have been banned in Kaikohe, Northland, due to the dry weather.

The east coast of New Zealand is at most risk of fire due to 'extremely dry conditions'.

Forecasters and fire officers agree the risks are elevated in Northland, Auckland, Coromandel,Hawke's Bay, and parts of the Canterbury Plains.

Firefighters have struggled to control a 350-hectare forest fire near Napier, which was still burning on Tuesday evening. The cause of the blaze has not yet been confirmed.

Fire risk is calculated using auto weather stations giving drought data, rainfall, wind speed and direction, and the type of fuel available like scrub or grassland, Fire and Emergency New Zealand (Fenz) national fire risk management advisor Rob Goldring said.

Sheep graze in a drying out Amberley, North Canterbury.

* Napier forest fire spreads to 300 hectares

* Emergency services prepare for busy fire season as heavy vegetation growth boosts risk**

Fenz encouraged people to check the website www.checkitsalright.nz before operating machinery or starting fires.

About a quarter of all wildfires are started by camp fires each year, and 30 per cent by land clearing fires like the one that ripped across 8ha of farmland in Bannockburn, near Cromwell, in November.

'It only takes one small spark to start a major fire,' Goldring said.

The key was to prevent fires happening in the first place by clearing piles of undergrowth and clearing gutters, particularly in areas like the Port Hills.

Sheep in a dry Waipara, North Canterbury.

Parts of Canterbury were at high risk of fire this summer, particularly Ashburton and inland South Canterbury.

North Canterbury principal rural fire officer Bruce Janes said the fire season has not been as busy as last year.

News of the fires in Australia had possibly contributed to heightened awareness among the public, he said.

'We are expecting some relief this week with rain, but conditions are steadily climbing through fire dangers towards very high and maybe extreme.'

A dry North Canterbury, looking from Mt Cass Rd towards Doctors Hills.

The 'coastal strip' from Cheviot to south Kaikōura 'is the worst area for us' in terms of fire risk and years of soil moisture deficit.

For the 'first time in many years', fires were being lit by lightning – including three that happened in just one day in North Canterbury about three weeks ago, he said.

'That is unusual for New Zealand.'

The Port Hills were 'not bad', despite 40 to 70 per cent of the grass seeding and dying off.

'It's almost slightly below average. It will get worse quickly.'

Fenz had received calls from people concerned about the possible fire risk, but the land had been mowed and grazed, and staff had undertaken multiple training days since the 2017 Port Hills fires.

'That worry is still pretty real … we understand that.'

Niwa forecaster Nava Fedaeff said soil moisture was lower than normal for this time of year, particularly in Northland, Auckland, north Waikato and Coromandel.

North Canterbury and northern parts of the West Coast were also dry.

On its drought index, there were 'extremely dry conditions' in east Auckland, Coromandel, east Wairarapa and coastal eastern areas.

'It's certainly something that we're going to be watching as the summer continues.'

Fedaeff said the dryness was expected to get worse in the short-term, especially with little rain expected over the next 10 days.

'It may be that we get some spots of meteorological drought popping up towards the end of the month.'

Blue Skies forecaster Tony Trewinnard said the South Island and central west parts of the North Island would 'dry out significantly until the end of the month'.

Dryness in the South Island would continue until the end of March, whereas the North Island was likely to get more rainfall by February, he said.