By Tony Orman
In 2017 the late Bill Benfield wrote an excellent book “Water Quality and Ownership” published by Tross Publishing, in which he criticised the new found novelty for fencing riparian strips along rivers and streams.
He wrote “the fact is riparian planting does nothing to stop nitrates from entering the waterways.”
And it is nitrate run-off which is so damaging to aquatic life whether it be trout, salmon or native fish. The NZ Federation of Freshwater Anglers instigated nitrate testing mainly in Canterbury and the results have been startling.
The work has revealed unacceptably high levels of nitrate pollution in rivers and streams across Canterbury. On top of that nitrates in drinking water taken from aquifers has according to a Danish study of 2.7 million cases, to show a probable link to stomach cancer in people.
NZFFA president Dr Peter Trolove recently said the massive increase in the amount of irrigated farmland across Canterbury in recent decades has resulted in a comparable reduction in the region’s water quantity and quality due to over-allocation of water for irrigation and nitrate pollution.
The stimulus for Peter Trolove’s investigation was in declining salmon and trout populations.
“The region’s recreational fisheries at large braided river mouths and in smaller lowland spring fed streams and rivers have seen trout numbers decline to near extinction,” said Peter Trolove.
The decline began at least a couple of decades ago – probably well before.
In 2000, the decline in lowland fisheries was revealed by Wayne McCallum, North Canterbury Fish and Game’s Environment Officer, wrote about lowland trout rivers and said that “on careful study, there appears to be more than a problem. Rather the evidence points to a wholesale crisis.”
Wayne McCallum cited two examples, Canterbury’s Selwyn River and the Horokiwi Stream, north of Wellington, a stream that was the subject of scientist Radway Allen’s classic study of a “typical New Zealand trout stream.”
But no action seemed to result from Wayne McCallum’s strong warning.
In 2010 Aquatic Ecology Limited in a report for Fish and Game NZ “depicted significant shifts and declines in trout spawning activity.”
Some 18 years ago Fish and Game NZ started raising concerns about dairy run-off into rivers. It was termed “Dirty Dairying”. That concern was proper. The vehicle for the strong message was poor. Rather than persuading the dairy sector of the crisis it was poor public relations, alienating farmers rather than bringing them into an cooperative endeavour to seek solutions.
Nor was it helped by the National government led by PM John Key and the volatile Nick Smith as Minister for the Environment. The duo spear-headed the move to sack a democratically elected body in the form of Environment Canterbury (ECan).
Nick Smith – volatile Minister for the Environment
ECan may have been struggling but it wasn’t the government’s role in an open democracy to carry out a State takeover – communistic in style – of an elected council.
Forget for an instant ECan’s role. This was a State grab for power and control.
Was the purpose simply to facilitate “unbridled’ expansion of intensive dairying particularly of the corporate kind?
As for riparian strips they began several years before the State squashing of ECan.
When the heat came on with Fish and Game NZ’s “Dirty Dairying” campaign, Fonterra the biggest player in dairying, moved quickly to deflect attention by proposing the Dairy and Clean Streams Accord of 2003. It s a text book example of a Clayton’s solution – how to maintain and expand intensive agriculture and its serious degradation of rivers while avoiding the real problems.
It involved fencing off river (and lake) margins and banning all animals from waterways.
Native Plantings along a stream
As an added public “sweetener” for the “green” lobby, the fenced off river margins were to be “planted with natives.”
Not only was it been successfully sold to central and local government but also to Fish and Game, the Green Party and any others willing to swallow the Clayton’s Solution..
As history proved, the Fish and Game campaign by settling for fencing rivers, did nothing to stop the huge expansion of dairying in low rainfall areas such as Canterbury and the Mackenzie Basin.
By focusing on dairying, it has deflected attention from the other major polluters, a classic case being the 2009 report on the Manawatu by the Cawthron Institute which rated the river as the dirtiest in the Western world and pointed the finger firmly to dairying
In fact, the Manawatu River had to put up with partially treated sewerage and untreated storm water from towns ranging from Eketahuna village (450 people) to Palmerston North city (88,000).scattered through the huge catchment. The river and its tributaries carries industrial burden from breweries, pharmaceutical works, milk processing plants and freezing works and there is also forestry and council bulldozer operations in the river bed. contributing to silting.
But to return to fencing off riparian strips as a solution for dirty dairying – fencing off rivers sounds good in principle, but the reality is quite different.
Ironically, the only thing achieved was the exclusion of the public and recreational fishers who are Fish and Game license holders, plus of course, a few animals.
River and stream margins no longer subject to browse converted to riparian strips quickly become overgrown thickets of blackberry, broom, convolvulus, gorse and even poisonous tutu.
Not only does the river thereby become inaccessible to the angling public — but riparian planting does nothing to stop most pollution entering the waterway.
And the fact is riparian planting does nothing to stop nitrates in particular from entering the waterways.
River margins can be managed better. It just requires a more focused system of river management.
There is certainly a case that where there is no intensive dairying, river banks should be left as in near as natural unfenced condition as possible.
Thereafter the issue is stock. Stock like sheep, goats and horses at the density of traditional farming, are not a problem.
Cattle can be a different issue. Where cattle densities are high and stock receive supplementary feed from offsite, they should be kept far from the river – it could be 50 metres or more. In such situations the ideal would be to significantly de-stock the land.
If fixed stock are grazed, i.e. sheep and cattle, then the “selecta-fence” can be the answer – two top wires to stop cattle and no bottom wires so as to let sheep through.
As an example of corporate posturing by big dairying to take the heat off, the fencing of rivers programme has been a stunning success.
But almost certainly, it has done nothing for the rivers.
It has allowed their continued degradation, often unseen and for most purposes, particularly recreation, rivers become no longer accessible.
Nor does riparian planting stop nitrates from entering waterways.
The problem is a water catchment one not a three or five metre weed infested strip alongside the river or stream.
Dr. Peter Trolove, NZFFA president
In theory riparian strips are a “feel good” thing but they fail to deal with the overall problem which is a watershed one. My experience has been of streams in the Wairarapa, flanked by a blackberry jungle making access with a fly rod impossible.
Most importantly they do not deal with the leaching of contaminants into the aquifer and ultimately the water.
Definitely a catchment issue. Time to reinstate water boards along with the new drinking water quality assurance rules, perhaps? Simply reporting UV filtered and chlorinated water delivered to the toby totally ignores the underlying problem.
I agree with most of what’s said in your article Tony. The Canterbury Water Management Strategy (CWMS) did nothing to alleviate nitrate poisoning except promulgate their “Overseer” model which they knew was dodgy (now proven to be useless). Everyone on the CWMS and in ECAN knew this, but riparian planting was still “sold” to the public by ECAN as the panacea for dirty dairying.
Riparian planting is, however, good for water quality in three ways:
1. It tends to cool the water down through shading. This improves oxygenation of the water, amongst other benefits.
2. Riparian vegetation does capture quite a lot of bioactive phosphorous, which reduces eutrophication. It doesn’t capture much nitrate because that gets in principally via groundwater.
3. Riparian planting creates fish habitat, especially for eels, and habitat for smaller fish. Insect habitat is also created, which is good food for trout (e.g. willow grubs).
So, creation of riparian habitat is good, but as you say it’s no panacea for nitrate poisoning.
Definitely a catchment issue. Maybe it’s time to reinstall water boards, along with the Drinking Water Quality Assessment Rules. Reporting UV and Chlorinated water delivered to the Toby is simply ignoring the underlying problems; some would say deliberately.
1. Prof Mike Joy has spoken of the uselessness of riparian planting. When dairying occurs on porous soils, nitrates simply filter into the waterways. As a Clayton’s remedy it suits the farming lobby though.
2. I believe Nick Smith wants to run for the post of Mayor of Nelson. Some people don’t know they should quit while they’re behind. This is the man who wanted to give us wadeable rivers, remember. (Mind you under the current administration we seem to be getting observable rivers – look but don’t touch.)
New Zealand’s waterways are some of the most degraded in the developed world. Will the Ardern government honour its several promises since 2017 to clean it up or would Māori iwi not procrastinate like government and tackle the situation?
Ngāi Tahu, New Zealand’s wealthiest Māori tribe, is apparently taking a legal case seeking “rangatiratanga”, or chieftainship, over most of the South Island’s freshwater.
On the surface things look okay with braided rivers turquoise from the glacial flows against a backdrop of snow-capped mountains. “100% Pure New Zealand”?
But behind that clean and green image is a dirty truth — NZ’s freshwater rivers are among the most polluted in the developed world. A recent government report found nearly 60 per cent of the country’s rivers carry pollution above acceptable levels, with 95 to 99 per cent of rivers in pastoral, urban and non-native forested areas contaminated.
Canterbury’s Selwyn River once a world famous brown trout fly fishing river, today reflects the inaction by recent governments both Labour and National and also the Ardern government’s bed-fellow the Green Party. The Green Party has woefully lost its way, forgotten its environmental roots now intent of social and cultural engineering.
The Selwyn experiences regular algal blooms, due to excessive nutrients, including nitrates. Praise for the NZ Federation of Freshwater Anglers for initiating nitrate testing and exposing the dirty shameful truth. The Selwyn runs into Lake Ellesmere, one of the most polluted lakes in NZ. Upstream, the Selwyn’s pollution has created a toxic hazard putting human health at risk. The river was once popular for swimming spot. Now signs warn about algal blooms and say “not safe to swim”.
Shame on PMs John Key and Jacinda Ardern and the cabinet MPs who sat on their hands. Both governments are environmental Philistines, i.e. vandals.
Well spoken, earlier correspondents. Jacinda Ardern’s Labour government keeps promising but doing nothing. To some extent a hurdle is the powerful dairy industry, much of it owned by corporates. Corporatism is foreign to the environment.
The Key National government was irresponsible sacking Environment Canterbury (ECAN) in a state seizing of a democratically elected body and promoting dairying especially for corporates.New Zealand’s irrigated land doubled in the 15 years from 2002 and now takes up over half of the country’s freshwater use. Canterbury accounted for 64 per cent of New Zealand’s irrigated land in 2017.
The growth of dairy farms has created a major problem for New Zealand’s rivers, with nitrate buildup of danger to not only fish but human life (Danish study of 2.7 million people), faecal effluent from cattle and reduced flows with irrigators sucking water, thus pollution becomes more concentrated.