Dust bowled

The sun scorched New Zealand's rural hinterland over the summer of 2013. The drought reached across more of the country than any other in the past 40 years. Mark Blackham examines how the nation coped.

The sun scorched New Zealand's rural hinterland over the summer of 2013. The drought reached across more of the country than any other in the past 40 years. The heat burnt through $2 billion dollars the country desperately needed in the middle of an economic downturn. Mark Blackham examines how the nation coped.

The New Zealand Herald photograph was designed to shock. A farm contractor held a gun to the head of a cow. The headline proclaimed 'Drought takes deadly toll'. That same night, television news led with a story that the Wellington region had only 20 days' water left.

It was 13 March 2013; the day New Zealanders turned from loving the exceptional summer, to fearing it.

A few days later the summer reached its driest point, according to NIWA's calculations. The whole of the North Island was officially declared to be in drought on 15 March.

The first signs had been spotted by NIWA five months earlier, when rainfall fell sharply below its average. By mid- November, a full month earlier than usual, the ground in some areas of the North Island's east coast had lost 75 millimetres more water than it had received. Spurred by the data, Primary Industries Minister Nathan Guy called the situation a "'green drought', where the land looks green, but still isn't growing fast enough".

Lower soil moisture levels mean less water for grass and other plants, so growth is retarded. Lack of grass means less for stock to eat.

So by the time townies stopped sunbathing and heard Campbell Live say the drought was "becoming the worst in living memory", farmers were already under great stress.

It was the widespread nature of the drought that hurt the worst. With everywhere suffering, there was nowhere to move stock, and nowhere nearby to source stock feed.

Some farmers were spending upwards of $2000 a day to buy stock feed. Many calculated that it was cheaper to send stock to slaughter earlier, and in greater numbers, than usual. Forty per cent more cattle were killed than usual during the period, and 23 per cent more sheep.

Lame cows that couldn't walk to find grass were killed rather than be left to starve. Hence, a busy time for the slaughterman pictured by the New Zealand Herald.

Farming support networks were putting most of their time into dealing with the emotional stress on farmers. The Waikato Times published a story about an accountant who talked down the gun a share milker had to his head.

The economic cost was high. Treasury has estimated the cost to be up to $2 billion over the entire period – knocking 0.7 percentage points off the annual GDP.

It was variously described as the worst drought in 30 years, the worst in 70 years and the worst in history. NIWA has since calculated that no other drought in the past 40 years has been so intense over such a wide area of New Zealand.

The emotional response to the drought confirmed our nation's sensitivity to weather and water, and particularly to its effect on our rural economy.

Federated Farmers President Bruce Wills summed up the reason for the acute reaction: ''We are a grass-fed economy. If the grass does not grow, the entire economy feels it." 

How hot was it?

It was hot during the summer. The highest temperature reached was 35.1 degrees in Clyde and Gisborne in January.

NIWA's records show that mean temperatures in February were above average, but not exceptionally so – the light winds and clear skies meant the afternoon maximum temperatures were well above average, but the overnight minimum temperatures were below average.

It was the sunniest February on record for numerous locations across both islands. Wellington and Hamilton recorded their sunniest February on record, Tauranga experienced its second sunniest February, and Christchurch observed its third sunniest February.

The real protagonist – the killer of grass and plants – was not heat, but lack of water.

February rainfall totalled less than 15 millimetres (a mere 15 per cent of normal) in parts of Northland, Auckland and the Bay of Plenty.

It was the driest February on record for Leigh (north Auckland) and Milford Sound. In the case of Leigh, it was also the driest month (of any month) since records began in 1966.

The dryness was widespread. Rainfall was less than 25 per cent of February's norm around Taupo, parts of Gisborne and Hawke's Bay, and along the West Coast of the South Island.

Which is why, when NIWA was asked by the Ministry for Primary Industries (MPI) to review the drought, it concentrated on calculating levels of soil moisture.

Ministry for Primary Industries website 

A useful method to estimate dryness is a soil moisture model that calculates potential evapotranspiration deficit (PED). PED is the amount of plant-available soil water needed to be added as irrigation, or replenished by rainfall, to keep pastures growing. The model estimates the moisture deficit balance between the net loss of soil moisture by evaporation and transpiration (evapotranspiration) and the gain by rainfall.

PED was calculated on a daily basis at rainfall-measuring locations in NIWA's climate station network, and at grid points on the Virtual Climate Station Network (VCSN), which are spaced about five kilometres apart over the country.

Virtual Climate Station data and products

As the growing season advances, evapotranspiration typically exceeds rainfall, and the moisture deficit increases. The higher the PED rating, the higher the water deficit, and the soil becomes drier. The typical threshold for moisture- constrained plant growth is about 75 millimetres of water deficit – reached by many North Island farms a month or more earlier than usual during the 2012–13 growing season.

NIWA Principal Scientist, Climate Variability, Dr Brett Mullan says the PED over the growing season from July 2012 to May 2013 was "one of the most extreme on record". 

"The PED was the most severe and widespread since at least 1972, with one-third of the North Island having the highest deficit in the VCSN data period."

NIWA's VCSN system goes back to 1972, but longer-term station records go back to the early 1940s. So NIWA was able to calculate that in some regions it was the most severe drought since 1945–46.

In total, the areas most affected were southern Northland, Auckland, Waikato, Bay of Plenty, the central North Island, Gisborne, Hawke's Bay, Wairarapa, and parts of the north and west of the South Island.


According to the MPI's Pastoral Farm Monitoring Report, farmers racked up $2.5 billion of debt with banks between January and April.

They needed loans to cover drops in production, lower value of products sold when supply was high and increased costs of feed.

Tauranga Chamber of Commerce Chief Executive Max Mason estimates that dairy farmers in the Bay of Plenty lost about $74 million from the drought.

DairyNZ recorded an 11 per cent drop in that region's milk production compared with the previous season, an average loss of $95,000 to $135,000 per farm. Meanwhile, costs went up. Bay of Plenty Federated Farmers Provincial President Rick Powdrell says feed prices increased by 20 per cent, raising the feed bill per farm to at least $25,000.

Derek Spratt, Chairman of New Zealand's Rural Support Trust, was telling farmers to "forget about this season; start concentrating on next season".

Financially squeezed and budget-conscious farmers had a flow-on effect throughout their communities.

Max Mason says dairy farmers had stopped spending.

"The firms who supply the industry are often forgotten and the drought will have impacted on their livelihoods and survival."

Around 22,000 people are employed in the $2 billion rural contracting industry. Rural Contractors New Zealand Chief Executive Roger Parton says many of their 450 members have suffered flow-on effects from the drought. Farming contractors in the Bay of Plenty claim to have lost up to 50 per cent of their work over the period.

It wasn't just the agricultural sector with dust between its toes. Low lake levels due to drought lifted wholesale power prices. The average wholesale price for power jumped to about $250 per megawatt hour in Wellington and $400 per megawatt hour in the upper North Island – about four or five times normal levels. 

Meridian Energy reported that the February rainfall into Lake Te Anau was the lowest since records began 80 years ago. Other hydro power stations on low lakes were at Manapouri, Lake Taupō and Lake Tekapo.

April was Mighty River Power's lowest month ever for hydro production, contributing to a 16 per cent fall in electricity generation in the last quarter of its financial year.

And it wasn't only sheep and cattle starving over summer. The drought is thought to have made it tough for many native species.

Anecdotal reports from the far north said thirst and dry soil were pushing the brown kiwi into residential areas.

A University of Canterbury study revealed that about a quarter of the hardy but endangered native brown mudfish died over the drought period. This effect on a fish known to handle long periods without water has worried scientists that the drought will have harmed less-resilient species.

According to Pete McIntosh, Hawke's Bay Fish & Game New Zealand Regional Manager, reduced river flow during the period changed the ecology of rivers, reducing the size and numbers of fish. 

Still burning

In early April, three long dry weeks after that controversial cow photo crystallised public concern, NIWA Principal Scientist, Climate Variability, Dr Andrew Tait appeared on TV3's Firstline programme to declare that "the most likely outcome [for Autumn] is to get about normal rainfall for the three month period".

Within two weeks rain began falling. In many places it began falling hard. At Tauranga, the first three months of the year were exceptionally dry – at 4mm (Jan), 31mm (Feb) and 20mm (Mar). Yet this was followed in April by a total of 284mm (236 per cent of normal).

The coming of the rain was not the end of the drought. The poor growing season, slow recovery of bores and weakened financial state of agricultural communities meant New Zealand was ill-prepared for the heavy rains and snow of winter.

Katie Milne, Adverse Events Spokesperson for Federated Farmers, tells W&A that there will be a long-term "carry- over" effect of the drought.

"There is no doubt this year has been challenging to say the least. "The adverse winter comes on the back of people having to offload stock where appropriate and buying in extra feed at a high cost.

"This has led to a lower number of milkers in some cases, and lower lambing rates are still in the making. Beef + Lamb New Zealand estimates a drop of three million lambs in the coming spring."

MPI's Resource Policy Manager, North Island Regions, Stuart Anderson says that although the rain returned and farms started to recover over the good autumn conditions, the economic and social impact of the drought continued.

"The [July] snow makes it harder for farmers to see themselves through the winter and manage feed supply and pastures."

He says the adverse event declaration of the drought will remain in place until 30 September to "allow rural communities to get through winter and into early spring".

Federated Farmers' Katie Milne says the full effect on farmers is yet to become clear.

"The drought has truly sunk its teeth into farmers. The average sheep and beef production is down 10 to 20 per cent in live weights, and dairy 8 to 10 per cent for milk production. There are still a few issues yet to raise their heads."

Although the picture for the rural sector is mixed, New Zealand's economy scraped through the drought with only a little pain. 

Before the drought hit, the New Zealand economy was thought to be in relatively good shape. Although the high New Zealand dollar, at US86 cents, was capping the excitement of very high international milk prices, interest rates were low, GDP was growing and imports were cheap.

The New Zealand Treasury's Monthly Economic Indicators Report in June said reduced agricultural production would cut growth by about 0.7 percentage points over 2013. It says the impact will be relatively short-lived, because the nation's growth will accelerate again "as the drought impacts fade over the second half of the year".

But the experience of the 1997 and 2007 droughts is that it takes about two years to get production back to normal levels after such droughts. Those droughts put 2013 into perspective. The 2007–08 drought cost $2.8 billion. It is credited with combining with the global financial crisis to tip New Zealand into recession.

That is why NZIER Principal Economist Shamubeel Eaqub was able to tell W&A that the drought will knock between 0.5 per cent and 1 per cent off GDP over two years. But he says that is relatively low by previous standards, and was only made possible because New Zealand was in a reasonable condition to face the drought.

"Going into the drought, the economy was forecast to grow by 2.5 to 3 per cent. Mortgage rates were low, businesses optimistic, the Canterbury rebuild was under way and surveys were showing strong hiring and investment intentions."

The optimism was confirmed when, in August, commentators said it would end up being a bumper season for the dairy industry. Fonterra announced that its 2013–14 season payout would be $7.50 per kilogram of milk solids.

Horticulture smiles

Some primary industries did very well basking under the intense sun. The wine industry was cock-a-hoop over the season.

Larry Morgan, Viticulturist at Te Mata Estate winery in Hawke's Bay, tells W&A that the taste and quantity of the 2013 grape harvest will make it an "exceptional" year for wine.

"2013's drought conditions concentrated both sugar and acid in the grapes, giving remarkable quality. From fresh, early-release whites, through to Hawke's Bay's greatest full- bodied reds, these wines will raise the bar for New Zealand wine."

Morgan says cool clear nights generally result in higher acid levels in New Zealand grapes than achieved in other countries. The acids in grapes are critical to the flavour and aroma of the wine.

"The favourable balance of sugar and acid gives New Zealand wines their unique taste. Daytime heat during the drought allowed sugar to rise to about 22 per cent of the grape content, but cool clear nights prevented the grapes from respiring their acid." 

Morgan says even some of the 2013 harvest wines already coming onto the market are noticeable for the quality of their taste and aroma.

"Some of the finer wines won't be available until 2015, but they will be absolute stunners."

Even grapes need water, though. Throughout the four months of the drought, New Zealand's vineyards applied about four litres of water per vine per day. Virtually all of it was sourced from on-site bores drawing from the water table.

"We could see the bore level falling over the period, but it never looked like running out," Morgan said.

Learning to cope

Bores into underground aquifers kept agriculture watered during the drought when low river flows triggered restrictions on water-take.

Dougall Gordon, Groundwater Scientist at Hawke's Bay Regional Council, was watching closely as the water in those bores emptied. He told W&A that his region's bores were working overtime during the drought.

"We know the aquifer was stressed, because some of the groundwater monitoring bores hit their lowest recorded levels."

Despite the public alarm over lack of rain, the water supply was strained but not critical. In fact, it appears that the bores quickly recovered once the drought broke.

"Monitoring data have shown that water levels in the aquifers recovered once the drought broke. The 'normal' predicted winter rain restored groundwater levels to its normal long- term range."

Gordon says the drought alerted people to the importance of security of supply of water.

"Groundwater can provide a more secure supply at times of drought, but taking too much groundwater has a cumulative effect on river flows when more water is abstracted from the system than is recharged. 

"This is why science to help underpin allocation decision- making is so important, and over the long term the challenge is to consider options for storing enough water for the times it is needed."

While bores fed plants, animals needed more than just water. A crucial decision for farmers was whether to sell stock for slaughter or buy feed to keep them going.

Dairy farmer Kevin White, who manages a 350-cow herd in Te Aroha, told Fairfax that he kept adjusting his plan every 10 days through the drought. His aim was to do what he could afford to "keep a core group of cows milking and at a healthy weight to set them up for winter". In mid-March he reduced the herd by about 70 cows so he could afford to feed the rest.

Crucial to those sorts of decisions during the drought were weather predictions and updated climate outlooks for the next few months. Farmers needed to know if and when rain would arrive. The longer it took, the tighter their budgets would need to be. 

NIWA's analysis of the current climate, using observations from both NIWA and MetService climate networks, and its outlook for the next 15 days to 3 months were regularly presented during the drought to the National Adverse Events Committee (NAEC) run by MPI. This Committee has met regularly over the past few years to maintain an ongoing assessment of the impacts of New Zealand's variable climate on primary production. NIWA weather and climate updates are typically one of the first items on the NAEC agenda. The updates are an important part of the mix of information that is used by MPI and other agencies for regional planning of rural support during adverse-weather events.

NIWA has also been supplying data to the Climate-Smart Farmers website (http://climate-smartfarmers.wikispaces. com/). This project, in collaboration with PGG Wrightson and funded by MPI under the Sustainable Farming Fund, maintains the site as a 'wiki' where farmers can get their hands on weather data and tools, and discuss management options with other farmers.

"We're working with specific farmers over a period of at least two years to determine what information is most useful for farmers to use in their decision making," says Alan Porteous, Group Manager, Climate Data and Applications, at NIWA.

PGG Wrightson and NIWA have held workshops with farmers to develop or adapt a range of climate products, including data sets, maps and derived information, specifically focused to assist farmer decision making on a day-to-day basis.

Porteous says it's not just about forecasting future weather. Being able to compare current weather conditions with past conditions helps farmers use their own records to judge what to do this time around.

Another NIWA tool helping the rural sector is the new NIWA forecast subscription-based service (see Q&A, page 42). The online tool creates a range of forecasts for properties as little as 12 kilometres apart. Information and forecasts calculated on NIWA's supercomputer incorporate data from the NIWA weather station that best represents climatic conditions on each property.

Not surprisingly, the drought caused consternation about the long-term challenges of regular droughts as the climate changes.

Finance Minister Bill English warned that farmers could not expect government support over continuous droughts.

Whether it's daily decision making or long-term planning, some adaptations appear necessary to get through future droughts.

"We have to adapt – there is no doubt about it," Federated Farmers President Bruce Wills says.

The New Zealand economy may have been lucky this time around, but the rural sector was undoubtedly hard hit. With many parts of the country expected to spend more time in drought as the century progresses, New Zealand appears determined to adapt.

Nathan Guy says water storage is a crucial answer to current and future droughts. "We don't have a shortage of water in this country – we don't have an ability to store that water."

That work is well under way in one of the regions hardest and most regularly hit by drought – Hawke's Bay. The region is considering a proposal for a new dam (Tukituki Catchment) and a water-storage scheme (Ruataniwha), which includes a dam and reservoir on the Makaroro River and irrigation canals on the Ruataniwha Plains.

NIWA is also part of a project in Canterbury aimed at vastly improving the efficient management of irrigation by using evapotranspiration measurements to judge the timing and amount of irrigation.

NIWA Water Resources Scientist Maurice Duncan says the Environment Canterbury-sponsored project is producing data essential to establishing the economic justification for irrigation and storage projects.

The project is showing that close monitoring of soil can enable many types of farming across many types of soil.

"It's a matter of understanding the flow of water through soils to keep moisture within a sweet spot for plant growth.

"We can accurately measure the water flows of different soils – and assess how much additional water is required to recharge soils.

"We're learning how farmers can fine-tune their use of water – to keep plants growing with the minimum amount of irrigated water."

NIWA's Canterbury irrigation project is a perfect example of the value of connecting weather science with farming techniques.

Brett Mullan says on-farm water storage, irrigation and drought-resistant grasses hold some of the keys to getting through future dry periods in more comfort.

Applying science to farming adaptation is not only possible, it is essential, says Alan Porteous. "New Zealand experiences a dry period in some region of the country almost every year. It's a fact of life here that we must plan for." 


Speed reading the drought

NIWA is a permanent member of Ministry for Primary Industries' (MPI) National Adverse Events Committee – a group of experts and representatives from primary industry, rural support groups and government agencies. The Committee discusses and shares information on the scale and nature of adverse events affecting the primary sector – such as drought, floods and snow – to coordinate recovery activities and help the primary sector to get back on its feet quickly.

MPI's Resource Policy Manager, North Island Regions, Stuart Anderson says NIWA kicked off each of the regular meetings during the drought with a run-down on the climatic conditions and outlook.

"The national and local picture of climatic conditions, soil dryness and the long-range seasonal outlook gave us the big picture. Then each industry described how they were being impacted, and how they were coping."

"That understanding of the size and magnitude of the drought, and how it was directly affecting people, meant we could discuss ways of helping."

Trish Burborough, MPI Policy Manager for the South Island, sat on the Adverse Events Committee along with NIWA's representative, Dr Andrew Tait.

"NIWA helped us understand the size and severity of drought – to put it in historic context and establish that we were indeed facing a significant adverse event."

Burborough says there was a particular focus on helping farmers. "Farmers needed NIWA's information for their decisions on how to adapt."

As the drought began to end, and particularly following NIWA's analysis of the 2013 drought, Anderson says Committee discussion also focused on long-term adaptation.

"There's a lot of interest in the causes of this particular drought. It was a different pattern to what we are used to. People are worried about the prospect of more in the future and asking, 'What do we do?' That's why MPI continues to invest in research on adaptations and resilience." 

What caused the drought?

New Zealanders have begun to understand the fluctuations and impact of the El Niño and La Niña systems. Severe droughts in 1972–73 and 1997–98 were both El Niño years. But this drought was caused by neither.

NIWA found that the dryness was due to slow-moving high pressure systems over the Tasman Sea and New Zealand during summer. These effectively blocked any other sorts of weather systems approaching the country.

Dr Andrew Tait famously told TV3's Firstline show: "The climate got stuck."

The unusual weather created a special challenge for forecasters. "We had a lot of anticyclones sitting over the country. There were fewer patterns, so we were relying on less useful information."

Dr Brett Mullan agrees that the latest drought was very different from others, but believes we'll see more of these sorts of droughts.

"High-pressure anticyclones during summer is a trend that is increasing, according to century-long pressure records." 

Declaring a drought

The National Drought Mitigation Center in the United States says a drought occurs when there is not enough rain for an activity or environmental sector for at least a complete season, or more.

A drought is not just a physical phenomenon, measured by environmental factors. The Center says the stress of a drought results from "the interplay between the natural event (less precipitation than expected) and the demand people place on water supply".

NIWA's drought analysis was essential to New Zealand's understanding of the big picture, according to MPI Resource Policy Manager, North Island Regions, Stuart Anderson.

"Anecdotally we were told the drought was the worst some farmers had experienced, but it is important to have this analysis to understand how dry the regions were compared with previous droughts."

Declaring a drought matters administratively, because it is the threshold at which the Government provides extra funding through rural support trusts to support rural communities, and some people experiencing hardship may also be eligible for income support through Rural Assistance Payments. Some tax measures can also be accessed through Inland Revenue.

The New Zealand Government needs to be requested by local authorities to declare a drought. MPI collects information to help the Minister make the official decision. It considers the environmental factors using data supplied nationally by NIWA and locally by local authorities. It then considers the operational effects – how people, stock and commerce are faring.