Why fencing waterways on dairy farms is not enough

Geoff SimmonsEnvironment

The above image is from a polution report by Doug – Dairy cows mob stocked along a stream, the waterway was fenced off by a hot wire but all the cows were inside the wire


As we saw in our last blog, the cockies are right when they point the finger at towns and cities for their impact on water quality. However, this is less than 1% of the waterways in the country. Almost half (47%) of the waterways in the country run through pastoral land. And these waterways, on average, have bacteria counts 40 times the natural level. Fencing waterways on Fonterra farms is not enough – we need to do the whole lot.

Note that we’re only talking bacteria here, not the other damaging impact on waterways from farming; excess nutrients. The nutrients in our water, nitrogen in particular, have been the major water quality focus of late because they are on the rise, as a result of increased dairy farming. While in some areas the trend in nutrients is a bigger threat to the overall health of our rivers, bacteria is probably a bigger issue when it comes to whether we can swim in our fresh water.

Why did the cow cross the stream?

The main cause of the bacteria problem is animals having direct access to our waterways. When animals walk through a stream, they are 50 times more likely to defecate than they are at any other time. Immediately after a herd of 250 cows have crossed a stream, E. coli levels in that stream will have quadrupled. This predilection for relieving themselves while standing in water may be something to do with the change in temperature, or perhaps like humans the sound of running water makes them want to relieve themselves.

That is why fencing off waterways is so important – it stops cows and sheep from getting into waterways, which stops them from crapping in them. As we saw last week, dairy farmers are making real progress fencing off streams, with Fonterra now having 95% compliance with their fencing requirement. However, this has given the impression that this means the job is done. Nothing could be further from the truth.

Waterways on sheep and beef farms don’t have to be fenced…

Dairy might make up the bulk of New Zealand’s exports, but it is not the majority of our farmland. Sheep and beef farmers use two thirds of the farmed land in the country, compared to 17% for dairy. The startling fact is that sheep and beef farmers have no legal requirement to fence their waterways. So even with the fencing of waterways on dairy farms there are still a lot of cows and sheep entering our waterways, which explains why E. coli levels remain so high.

… even when they are used to graze dairy cows!

The truly terrifying aspect is that sheep and beef farms are often used to host dairy cows during winter when the cows are dried off. Because they are not milked at this time, they don’t count as dairy farms and the Fonterra directive does not apply. So, thanks to this gnarly little technicality, it is still possible for dairy cows to frolic in our waterways.

Fencing waterways on sheep and beef farms will not be easy. For starters many of them operate on steep hill country, where fencing of any kind is a challenge. Also many sheep and beef farmers are not quite so flush with cash as dairy farmers, so they may not be able to afford the expense. As we have seen in the stories we have covered, some sheep and beef farmers are stepping up and doing the work voluntarily – often with part-funding from Councils.

And we have a small minority of naughty farmers

Finally, and most tragically, a small minority of farmers are still getting caught discharging effluent directly into our waterways. This is the crap collected while the cows are in the milking shed or on a feed pad. Most farmers now store the dung and spread it on their pasture as fertilizer when weather is dry. However, not all have made the necessary investment to do this properly in all conditions, and the effluent ends up in our waterways.

In the Waikato region alone 59 farmers have been prosecuted for dairy effluent discharges since 2005 – amounting to just under 1% of the farmers in the region. Just last week a farmer was fined $55,800 for deliberately discharging effluent into a wetland because they had no storage pond for it. This is just the tip of the iceberg, with many more infringement notices and warnings handed out. And remember that the Waikato is also just one region – albeit our biggest dairy farming region making up 28% of our total national dairy herd.

We must keep stock out of waterways

Aside from dealing with these offenders, the solution to this problem is really quite simple – stop stock entering our waterways. Recent trends suggest that E. coli levels are improving in farmed areas, and this appears to be due to action from dairy farmers to fence off their waterways and ensure cattle cross rivers on bridges. However, modeling for Southland suggests that simply applying this rule to dairy farms is not enough. If we want our rivers to be safe for wading, let alone swimming, sheep and beef cattle also need to be excluded from our rivers. This is surely just common sense – after all cow poo stinks the same if it is from a dairy or beef farm.

And leave wide riparian margins too

This will not be a foolproof solution – faeces could still be washed into our waterways during flood events. That is the one time when you probably shouldn’t risk going swimming, either in urban or farming areas. This issue can be reduced in farming areas by ensuring that all riparian margins (the fenced off bit of land by the river) are sufficiently large. By letting the grass grow and/or planting them with vegetation, this helps ensure that any flood water gets filtered on its way into the stream. At the moment not even dairy farmers are obliged to have riparian margins – they simply have to have a ‘plan’ by 2020. As a result some fences are perched on the edge of riverbanks – which means that cattle are kept out of rivers but some effluent may still be washed from the land into the water.

The long-term ideal would be to fence and plant not only rivers but also any steep gullies, as this is where rainwater collects soil and poo on its way to our streams and rivers. These are so-called ‘ephemeral streams’ – places where temporary streams form during heavy rainfall events – which are also not subject to any fencing requirement.

How can we achieve this goal?

It is clear that the days of stock in our waterways should be numbered. Yet this will require funding, and sheep and beef farmers may not be able to foot the bill. One solution we have raised previously is that dairy farmers (particularly new conversions) via a mechanism such as pollution trading rights could help pay for this work in order to offset the impact of their intensive farming. Whether this is enough to offset the damage from increased dairying would have to be measured through the best indicator of waterway ecosystem health – the Macroinvertebrate Community Index.

In the mean time we have to send a clear message that we need to keep all stock out of waterways, no matter what kind of farm. You can help raise the profile of this issue by reporting any stock you see in streams using our pollution reporting app.


Why fencing waterways on dairy farms is not enough was last modified: December 15th, 2015 by Geoff Simmons
About the Author

Geoff Simmons

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Geoff Simmons is an economist working for the Morgan Foundation. Geoff has an Honours degree from Auckland University and over ten years experience working for NZ Treasury and as a manager in the UK civil service. Geoff has co-authored three books alongside Gareth.