The Canterbury Dairy Industry’s Impure Advantage


This article for the NZFFA has grown from my attempted contribution to the PureAdvantage organisation.

Taking the lead from the “criteria for PureAdavantage contributions”, I have included many hyperlinks to support my comments.


On Saturday 15 February 2020 two executive members of the New Zealand Federation of Freshwater Anglers (NZFFA) tested 75 well water samples from 62 properties in the Ashburton District. Ten percent of these wells contained nitrate levels above New Zealand’s Maximum Allowable Value MAV of 11.3 mg/L Nitrate-N (50 mg/L nitrate). The “toxic” wells were from Hinds, Winslow, Willowby, Tinwald, and Fairton. Fifty percent of the samples exceeded Environment Canterbury’s (Ecan’s) aspirational limit of 5.3 mg/L NO3-N. The lowest results came from wells close to nearby braided rivers and from outside the district.

The well owners all expressed their appreciation for the testing and their concerns about the results. Several mothers with babies and young children brought their water for testing.

[A rather long link is given which covers much of the Public Health debate around nitrate in drinking water: ]

Despite the obvious public interest, both local Ashburton papers elected not to report this event, no doubt reflecting the district’s reliance on dairying which underpins the local economy.

The NZFFA acquired its nitrate tester after helping Dr Mike Joy measure nitrate samples in 2018

North Canterbury’s Fish and Game’s new CEO Rasmus Gabrielson recently told the NZFFA that F&G has decided the region’s lowland rivers are a basket case and as a result North Canterbury F&G are conserving their resources for their high country fishery.

The NZFFA has been testing lowland rivers and streams in Central Canterbury since acquiring their own TriOS nitrate photometer in August 2019 after noticing trout were disappearing from the Hinds River, Harts Creek and Selwyn River due to nitrate levels over twice levels toxic to trout eggs and fry.

Due to inappropriate nitrate standards proscribed in the 2017 National Policy Statement for Freshwater Management NPS FM under the RMA Ecan is not compelled to act until an upper threshold of 6.9 mg/L NO3-N is crossed. In essence this standard accepts that 20% of New Zealand’s aquatic life is at risk. In other words New Zealand’s current freshwater standards put the economy before the environment.

The New Zealand Veterinary Association’s official magazine VetScript featured Canterbury’s water conundrum in its September 2019 edition. – polluted water- public health put at risk – and “dirty” politics.

In Canterbury, central and local government have placed GDP from intensive irrigated dairying above environmental and public health –the antithesis of “PureAdvantage”.


Canterbury’s water woes result from massive intensification of dairying made possible by doubling the land under irrigation and the use of synthetic nitrogen fertilizer:

Statistics NZ data reveals that from 1990 to 2017, the number of dairy cows in Canterbury increased from 112,999 to 1,308,058. The number of sheep fell from 10.4 million to 4.4 million. The amount of irrigated land increased from 240,778 in 2002 to 478,143 in 2017

NZ farmers used to rely on symbiotic bacterial colonies located in nodules within the roots of white clover to fix atmospheric nitrogen in exchange for carbohydrate. No leaching of nitrate occurred in this closed system. Since the development of the Maui gas field in the 1980s the Government has taken over the Kapuni ammonium urea plant and agreed to take the gas against the advice of leading scientists. The Government presently subsidises 90% of the plant’s CO2 emissions. Pasture production on Canterbury dairy farms has become dependent on synthetic nitrogen where on average 230 kg of N is applied annually. New Zealand (intensive and semi-intensive) farmers have become addicted to nitrogen.

Unfortunately the ten-fold increase in dairy cows made possible by a 300x increase in (ETS exempt) synthetic N fertilizer and massive (subsidized) irrigation development occurred on the country’s most vulnerable soils.

The coarse porous sandy outwash soils of the Canterbury Plains do not retain nitrate. Any nitrate in excess of that required for immediate plant growth is simply leached straight down into the aquifer beneath.

Dairy cows (female) make the problem worse – a cow urinates 10-12 times daily covering a patch between 0.4 – 1.0 m2 with a urea loading of 400 to 1000 kg / ha. In other words with the high 3.9 cows / ha stocking rates possible in Canterbury, approximately 1/3 of the pasture receives this massive annual nitrate loading in addition to fertilizer applications.

Leaching from excess nitrate from cow urine (and dung) exceeds that leached from fertilizer use by 200%.

Good management practice (GMP) regarding the use urea is based on using only amounts of fertilizer that can be taken up by plants. Due to seasonal plant growth GMP is very much a matter of the timing of fertilizer applications.

Farm environment plans (GMP) being developed by Ecan only address fertilizer use. Without addressing the excess nitrate from cows, Ecan’s farm plans will fail. Cows may need to be taken off pasture during autumn and winter months and their effluent carefully stored for later managed application to pastures. The only other known solution is less cows.

The many iterations of OVERSEER reflect the complexity of managing nitrate leaching.

When considerations of variable soils, climate, and scale are added, OVERSEER remains useful only for its ability to explain the concepts of nitrate pollution. It is not yet a suitable tool for regulatory enforcement.

An “Impure” Democracy

Why did the people of Canterbury exchange their once envied water for an increase in GDP when its regional council Ecan had known that nitrate contamination of the regions’ aquifers was occurring since at least 1986? Record Number: PU1C/6168 Date: 2 Aug 2002 Nitrate concentrations in Canterbury ground water: a review of existing data

The answer lies in New Zealand’s imperfect form of indirect democracy where we elect local and regional governments on pre-election promises and trust our leaders will act in our best interest.

Sadly in response to the 2008 financial crisis, the Key Government in its drive for more and more cows even in low rainfall regions, “sacrificed Canterbury in the interest of New Zealand”.

  1. Central Government

After advice from MAF advisors in 2009 and pressure from the Canterbury Mayoral Forum, key National Government ministers passed the Environment Canterbury (Temporary Commissioners and Improved Water Management) Act (Ecan Act) 2010. This Act passed under urgency, stripped Cantabrian’s of their democratically elected regional council replacing them with Government appointed commissioners and allowed the fate of the region’s rivers protected by National Conservation Orders to be decided by Ecan managed irrigation hearings. Such hearing decisions could no longer be appealed to the Environment Court, only to the High Court on points of law. The non-statutory Canterbury Water Management Strategy CWMS was given primacy over the RMA. Cantabrians were disenfranchised for almost a decade giving lie to the “temporary” commissioners.

  1. Environment Canterbury Regional Council Ecan

With oversight from Government appointed Commissioners answerable only to the nation’s “rulers”, Ecan kicked off the massive ill-considered irrigation development that has so badly affected Canterbury’s aquatic environments – over allocation of water for irrigation, pollution from nitrate and livestock sourced pathogens, agricultural encroachment of public river margins, and a virtual absence of consent monitoring &/or prosecutions.

  1. Central Plains Water

Irrigating Canterbury’s central plains using water from the Rakaia and Waimakariri Rivers has long been the ambition of local politicians and business leaders.

When It was rejected as a “think big” project of the Muldoon government due its lack of economic viability and public opposition, Cantabrians reacted to gain New Zealand’s second National Water Conservation Order for the Rakaia River, The National Water Conservation Order (Rakaia River) 1988, recognizing that this iconic braided river was likely to be lost through “death by a thousand cuts” due to water abstraction for irrigation.

The minimum flows proscribed in the NWCO successfully blocked the Central Plains irrigation development until the enactment of the Ecan Act 2010 which allowed Ecan to amend the Rakaia NWCO flows and create “stored water” in Lake Coleridge by redefining water used to generate hydro-electricity and returned as “flow of river” into stored water owned by TrustPower to sell to irrigators. By this device a further 70 m3 was consented to be abstracted from the Rakaia River catchment.

Only those with the patience and knowledge to read both the May 2010 Hearing decision to allow the take of a maximum of 57 m3 for the Barrhill Chertsey Irrigation and CPW irrigation schemes of water that was not available under the existing Rakaia NWCO and the subsequent take of 70 m3 made possible by the Ecan Act 2010 at the ECan Lake Coleridge Project (LCP) Hearing 2012 will realize that the advice to the respective Hearing commissioners that the effects of the takes and out of river use would be “minor or less than minor” was grossly incorrect. The Chair of the Hearing commissioners for the Lake Coleridge Project required TrustPower’s expert witnesses to swear an oath that they would abide by the Handbook for the Code of Conduct for Expert Witnesses in the Environment Court 2011. Perhaps this was to provide cover for the commissioners rather than improve the quality of the experts’ evidence? In any event, time has shown the experts’ opinions were not expert – the Rakaia River’s recreational and native fisheries have collapsed and the Selwyn District’s groundwater is now heavily polluted with nitrate and pathogens.

Central Plains Water Trust was created by the Christchurch City Council and Selwyn District Council in 2003 to facilitate the irrigation of Central Canterbury

Central Plains Water Trust, established with public money, funded the planning and consenting of Central Plains Water. The trust licenses the rights of these consents to the Central Plains Water irrigation company owned by 400 farmer shareholders.

The consenting hearings have been prolonged and contentious. The council led irrigation proponents won the day enabled by the constitutionally repugnant Ecan Act 2010 together with its incorporated Canterbury Management Strategy. · PDF file‘just-puppet-government-bidding-ch-137092

  1. The Canterbury Water Management Strategy

The CWMS is a living document, given statutory authority by the Ecan Act 2010, used by Ecan to create the rules and processes to manage the region’s water.

Dr Bryan Jenkins was Ecan’s CEO for seven years before being replaced by the Government appointed commissioners in 2010 he played a large part in the development of the CWMS.

His book published in 2018, , describes the overarching approach to managing Canterbury’s water – scope what is water is available – take the water that is most accessible – use the water in an efficient and integrated manner.

Unfortunately the (aquatic) environment appears have to have been ignored. The CWMS appears to see “Alpine Water” as somehow separate from the catchments which it supplies able to be used both for irrigation and mitigation of any harmful effects of Canterbury’s “water management”.

Dr Jenkins profile reveals he is well qualified in environmental management.

Under the post 2010 Ecan regime, the CWMS has enabled Ecan to set up the 10 water zone committees composed primarily of water users to manage each zone’s water while maintaining the pretence of community collaboration.

The CWMS has received poor marks on its environmental record.

  1. The Treaty of Waitangi – Lake Coleridge Hearing 2012

While waiting to make my submission to the Ecan LCP Hearing in 2012, I witnessed Sir Tipene O’Regan deliver a forceful broadside to the Hearing commissioners. A prominent Ngai Tahu leader who once headed Ngai Tahu’s commercial arm and who successfully negotiated Ngai Tahu’s Fisheries Settlement, Sir Tipene berated the commissioners stating that while others from Ngai Tahu were presenting submissions at the Hearing he was here for another more important purpose. He noted that Ngai Tahu was interested in the Hearing outcome as Ngai Tahu has extensive farming interests in Canterbury and under the Treaty Settlement Ngai Tahu owns the mauri or spirit of the Rakaia River. However his reason for addressing the Hearing was to express his anger at having to attend the Hearing as an ordinary New Zealander when the Treaty gave him the right to sit at the “top table”. He berated Ecan for its offense of not meeting with Ngai Tahu prior to the Hearing causing him the indignity of having to speak with the other submitters.

Sir Tipene’s stance might suggest the Treaty has created New Zealand’s own version of apartheid or was this simply the actions of a wily negotiator long used to exploiting PC attitudes endemic within local and central government?

  1. Fonterra

Fonterra’s pretence of being a responsible entity responding to the “dirty dairying” campaign of F&G through the Dairy Accord and a $20 million dollar partnership with DOC might also been seen as a cynical corporate protecting future profits?

Landscaping and fencing polluted streams with minimal margins will not stop nitrate from entering our waterways. (Although there will be benefits in reducing the amount of sediment and phosphate entering waterways).

Entering a ten year $20 million dollar partnership with DOC, the government department with the statutory duty to protect native fish and salmon and trout habitat, will create difficulties for DOC both in terms of DOC’s credibility and its ability to perform its role independently.

Dairy Farmers

The farmer is the obvious scapegoat for the nitrate problem, but is he the right one? There is no objective measure by which blame can be assigned, but if such a measure could be devised, politicians and economists might fare at least as badly or even worse than farmers.

Farmers who have signed up to recent irrigation schemes have had to do much soul searching before committing to a marginally profitable farming practice. Only after they invested in intensive irrigated (dairy) farming has Ecan raised the spectre of costly farm environment plans/restrictions.

Ecan is repositioning itself from the farmers’ friend to becoming the farmers’ regulator. This has resulted in a fall in farming confidence

  1. The National Policy Statement for Freshwater Management NPS FM Standards Review.

The Coalition Government holds the key to solving New Zealand’s water pollution through its stated intention to revise New Zealand’s inappropriate national freshwater standards. These standards give direction under the RMA to councils on the pollution limits deemed acceptable by Central Government.

Consultation on the Government’s proposed NPS FW standards has been completed.

We will soon learn if Ministers Parker and O’Connor can hold their nerve and not “kick the can down the road for future generations”. Their intent must be signalled before the September 2020 elections.


Captured disenfranchised Canterbury ratepayers have been made to fund the theft and pollution of their region’s water.

Canterbury (and visiting) anglers have seen their recreation ravaged.

Future generations of New Zealanders have lost their birthright.

This is the Canterbury’s dairy industry’s impure advantage.

Dr Peter Trolove BVSc MSc (Aquatic Veterinary Studies) MBA

President NZFFA


  1. Construction of CPW irrigation infrastructure
  2. A major braid of the NWCO protected Rakaia River re-directed by an adjacent landowner. Consented but not compliant with the NWCO. Not monitored by Ecan
  3. Ecan sign warning of toxic algae due to nutrient enrichment of the Selwyn River at the popular Coe’s ford swimming and camping site.
  4. Water testing at Ashburton.
, The Canterbury Dairy Industry’s Impure Advantage
, The Canterbury Dairy Industry’s Impure Advantage
, The Canterbury Dairy Industry’s Impure Advantage
, The Canterbury Dairy Industry’s Impure Advantage
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