PERSPECTIVE: By Gaylene Barnes, Filmmaker

By Gaylene Barnes, Director / Producer

Our film documents several dying rivers and we learn why this is happening. The film takes a broad and gentle hand to elucidate; we prioritise the communities most affected by it, those selfless souls who are working to restore health to their rivers.

It offers the potential to be “smaller, gentler and slower” in our moves upon the planet – rather than the modus operandi of “bigger, harder, faster”. And to have a profound sense of the diverse life that abounds in the waterways.

Our rivers and aquifers need urgent attention. I predict that in less than thirty years time our rivers will be lifeless, and our aquifers stuffed unless we make significant land-use changes now.

Sorry. Let me explain:

The film hears from scientists such as Tim Davies, chief scientist at Environment Canterbury, on the subject of nitrogen pollution: “Nitrates are toxic to fish, at levels that we do we find in these rivers.” We hear from Dr Graham Fenwick, an ecologist and crustacean systematist, on the subject of the tiny creatures that live in our aquifers and keep our water clean. He says “If the groundwater levels drop … then there is less oxygen, and it puts the whole ecosystem at risk.”

These two comments signify the two main problems degrading the life in our rivers, waterways and aquifers in Canterbury – nitrogen pollution and over-abstraction of water.

While we accept and understand the carbon crisis, we have little understood the nitrogen crisis on our hands‑—one which we can no longer deny. Man-made. Intensive-farming-made. We need to change our land-use practices. Immediately.

We need to get carbon back on the land, and find ways to get nitrogen back into the air, immediately. All our efforts must be towards this end – if we are to survive as a species.

Plants need nitrogen to grow—but the natural nitrogen fixing process(composting/nitrogen fixing plants) is not fast enough for industrial farming. So most farmers use synthetic nitrogen—urea— in vast quantities upon the land. Nitrogen levels on the land are now twice that found naturally. Globally. We have reached and blasted through the planetary boundaries of nitrogen loading on the land.

New Zealand is one of the worst offenders in the nitrogen crisis. Our synthetic fertiliser-use exceeds most OECD nations. In fact, according to World Bank data, we use similar amounts of fertilser as Bahrain—a desert, and Singapore—where it is mostly hydroponic farming.

According to World Bank data, we use comparable amounts of fertilser as Bahrain—a desert. SOURCE: World Bank

UREA is destructive in two ways – the excess nitrogen compounds wash easily through the environment, and into aquifers and rivers. But, more disastrously, urea has enabled the intensification of farming into drylands and deserts such as Te Pirita, Eyrewell, and the Mackenzie country (in combination with new irrigation).

The second reason is more devastating – because it is the stock that live on these hydroponically farmed marginal soils that contribute to the majority of nitrate poisoning of groundwater. Cow-piss primarily. Especially milking-cows, with their high-input protein diets, such as imported Palm Kernal Extract. They have urine that is heavily loaded with nitrogen.

A large portion of this is “lost below the root zone to waterways via leaching” according to DairyNZ.  A graph from DairyNZ shows this loss to be at least 30%.  Significantly more if the cattle are wintering on fodder-beet (see picture below). With no plants around to absorb these excess nitrates – the soluble nitrogen will continue it’s journey straight down into the aquifers and waterways.

Riparian strips or effluent ponds won’t make a difference when the dairy-cow is mostly standing on muddy gravel, in the rain.

Steers on a fodder-beet paddock at a Te Pirita dairy farm during winter rain = maximum leach. SOURCE: Gaylene Barnes

New Zealand is at high-risk of experiencing huge and extinction-level effects from this ‘cow-piss’ pollution. Of 175 monitored river sites in the pastoral class, nitrate-nitrogen trends were worsening at 61% of sites over the period 1994–2013. Of the native aquatic species the government reports on, around 75% of fish, one-third of invertebrates, and one-third of plants are threatened with, or at risk of, extinction.

New Zealand does not have a history of ruminant animals roaming our landscape. We are geologically young. Canterbury, in particular, is a bed of gravel from recently eroded mountains. Our native plants and fish are extremely sensitive to high nitrogen levels – they have evolved over millenia in a low-nitrogen environment.

Yet, we have allowed Waikato styled dairy-farming systems on our marginal Canterbury soils. We have also allowed a much higher dairy-cow stocking rate on our plains than in the Waikato. Many Canterbury farms are in fact owned by Waikato or North Island shareholders. Sipping their soy-milk latte on Waiheke Island, gazing at a spreadsheet.

In our film we looked at the effects of nitrogen pollution on our rivers – weedy waterways, toxic algae, death to native fish, loss of spawning grounds, loss of habitat for braided birds, increasing nitrate levels in drinking water – that sort of thing.

One of our characters states that they hate the term “nitrogen-loss.” He notes that “if it was a whole lot of paint factories in the upper Selwyn ‘losing’ paint into the waterways – they wouldn’t be calling it ‘paint-loss’ would they?”

What to do about it? Well, Environment Canterbury have proposed “nitrogen-loss” limits. And are forcing all farmers to apply for consent if their nitrogen loss levels are over a certain limit – usually about 15-20 kgN/ha/yr. All dairy-farms and most intensive farms are well over this limit.

ECan give them a “discretionary” consent. But they do not have to.

Selwyn folk rescuing fish from an algae infested river that is drying up. SOURCE: Gaylene Barnes

Lets look at an example of a local farm that has applied for consent to leach nitrates over the acceptable limit:

Purata Farms, with the motto “Farming for Tomorrow” is 99% owned by Chinese billionaire Zhaobai Jiang, who is neither a New Zealand resident nor a citizen. His company, Shanghai Pengxin, owns 4,000 hectares of Te Pirita gravel land, on the north side of the Rakaia river, marhinal land. Yet his managers are milking about 13,000+ cows for him. A very high stocking rate, that requires enormous inputs. They feed his cows PKE in the afternoons.

Mr Jiang is able to bunch all his nitrogen-loss limits together on his various pieces of land into one ‘baseline’ – which is sitting at about 57 kgN/ha/yr. Because millions of dollars had already been spent ‘developing’ the farm (putting in irrigators and milking sheds) before the limits were proposed —Mr Jiang is therefore considered a ‘grandfather’ and is allowed to keep leaching/ polluting at this higher limit, providing he implements ‘good management practice’ and starts reducing this limit over time.

I was advised by a Purata Farms employee to “not be focusing so much on the number as that principally is a guide.” I would absolutely agree with her. These nitrogen-loss limits are defined by a flawed modelling system called Overseer, designed by the synthetic fertiliser companies – an organic dairy-farmer we spoke to says “it’s like the alcoholics being in charge of the brewery.”

All the numbers / limits / figures plaguing our discussions on nitrogen limits are a nonsense in my opinion. This model does not truly reference the natural biological world.

This figure of 57kg/ha/yr seems ridiculously small compared to the actual tonnage of cow-piss applied on the land, every day. If cow-piss leaching is 30% of every 25 litres of urine, per cow, per day? Times X 13,000 cows on Purata Farms? You do the math. My own ‘cow-piss’ calculation puts it at 5.5 tonnes per year – from just one farm?

Mr Jiang’s milking-cows are polluting tonnes of nitrates below the root zone, on marginal soils, which are being washed straight down into the groundwater, and then flowing on into the spring-fed streams and Te Waihora Lake Ellesmere.

In all of Canterbury there are 1.2 million milking-cows, plus several hundred thousand more cattle. This equates to many millions of litres of urinary-N being ‘lost’ every day into our aquifers and waterways. What we are seeing now is only the beginning – it can take years for nitrogen-nitrates to leach through the groundwater system.

Remember, nitrates are toxic to fish and invertebrates living in our rivers and aquifers. They are also toxic to drink at certain levels. It may be your children and your grandchildren who will be drinking cow-piss. Thanks Grandfather Jiang.

The Rakaia river delta. SOURCE: Dave Perry

The second major issue our rivers are facing is the over-allocation of water to out-of-stream use—80-95% of all water-takes in Canterbury are used for irrigation and stock. This is causing the rivers to dry up.

Here’s a list of rivers that can’t be fished anymore for trout and eels – because they simply do not have enough water: Pareora, Makikihi, Otaio, Te nga wai, Ohape, Orari, Hinds, Hawkins, Selwyn, Irwell, Ashley, Haehaetemoana, Waihi, Temuka, Kakahu, Ashburton – North & Middle, Waihao… etc.

Unfortunately, some of the solutions being proposed to solve this over-allocation are irrational.

Excessive groundwater abstraction also lower the flows in the aquifers—making life difficult for the aquifer crustaceans and the water filtering service they provide.


A rational person, would suggest that this problem was best solved by—reducing groundwater takes.

Instead, irrigation advocates that this problem will be best solved by Big Engineering Projects, such as the Central Plains Water Scheme (CPWS), whose high concept is to introduce a “sustainable run-of-river supply from the surplus water of the Rakaia River.”

What is actually happening, of course, is that only some farmers are forfeiting their groundwater takes in favour of the CPWS, because it’s a lot more expensive, and less reliable. Only 20% of CPW irrigators have actually given up their groundwater consents.

Grandfather Jiang, of the 4000ha Purata Farms, is refusing to take more CPWS water, despite Environment Canterbury asking very nicely, because it is actually 4X more expensive than pumping from his ground and surface water-take consents.

The CPWS canal runs right past their place, and the shareholding Mr Jiang already has represents the largest shareholding of the entire scheme. Thus CPWS is therefore also a failed business model, and puts a lie to the statements from the CPW Trust, which owns the water-take consents, to ensure that “ownership of the consents will never pass to overseas or commercial/corporate interests.”

As an aside, I’m not quite sure how this aligns with Winston Peters policy of “the need to protect New Zealand ownership of key infrastructural assets” when we consider that Denis O’Rourke, the Central Plains Water Trust chairman, and a New Zealand First candidate, is happy to give away the ownership of local infrastructure, to Mr Zhaobai Jiang, an overseas-owned corporate.

Due to the introduction, and continuing development of CPWS what we have now is a lot more new shingly land being converted from drylands to irrigated land. Thus, we are not solving the problem at all, but simply creating another one.

One of our characters says: “If you’re getting into trouble, go back and look at your basics and see where you went wrong.”

A fundamental basic is this – it is the rivers that predominantly recharge the groundwater.

So it is irrational to take water away from the internationally significant braided Rakaia River to store it all winter in Lake Coleridge, to then sell it to irrigators at 8c per cubic metre, to divert the river into numerous channels, to suck it out of numerous surface-takes all along the length of the river, to continue to pump groundwater which must be recharged by the river—thus finally depleting the stunning and once mighty Rakaia River so much so, that it now leaks and limps its way to the coast.

Another example of irrationality is the claim that the CPWS will somehow “flood the plains” with all this water from the river, which will help to recharge all the lowland streams. This was promoted during the consent process as an incentive. They go on to claim that the irrigators will use the water so “efficiently that the plants will only get what it needs”. This is double-speak, plain and simple. More lies.

We now have scientists concerned because the irrigators are not so leaky anymore, as the old leaky drains and dykes were contributing to recharging the groundwater in the past.

So to solve this new and emerging problem, there is now talk of more Big Engineering Projects and to which the Taxpayers and Ratepayers are already set to contribute $2.2m – a Managed Aquifer Recharge Scheme. These are effectively leaky lakes which will be built to “recharge” swimming holes such as Coes Ford. Attempting to pacify the locals perhaps? I’ve heard they are planning to build dozens of these purpose built “leaky” lakes all over the plains.” And so it goes on, and on, on – what nonsense.

Let’s get back to basics – the river recharges the aquifer. We need to reduce surface-water takes and reduce groundwater-takes, immediately.

Our local dairy industry is deeply indebted, mono-cultural and unsustainable. It is feeding the long term wealth – not of Canterbury family farmers – but of banks, fertiliser companies and irrigation construction companies. The only profit being made is via capital gains on the land and holdings.

It is not feeding the long-term health of our soils and waterways. It could be. We want healthy resilient farms regenerating the soil, leaving the soil and our waterways better than we found it. A healthy primary industry sector needs to be diverse, resilient and regenerative.

We need to enforce penalties for all water and river polluters – city and country. That includes ruminant animal urine, nitrates, chemicals, anti-biotics, excess sediments, copper from brake-pads and all other poisons excreted from land-use and city activities.

We need to reduce our use of inputs on farm – such as synthetic fertilisers and palm kernel extract. If we cannot sustain our herds and crops on-farm, then we do not have a sustainable farming system.

I would suggest that the current style of dairy-farming in Canterbury is losing the communities ‘social consent’.

To this end we need to support Environment Canterbury – to refuse further water-take consents, to call in water-take and land-use consents that are putting rivers and aquifers at risk, to be brave in enforcing limits and taking action against high-polluters, and to be much more discrete in granting ‘discretionary’ resource consents for intensive land-uses.

The film Seven Rivers Walking – Haere Mārire is screening in Geraldine, Rangiora, Ashburton and Alices Cinematheque. We examine both city and rural problems affecting our rivers in this film.