Amuri Basin farmers drive water quality improvement

“Instead of the occasional chat at the pub, the formal structure meant discussions came with follow-through and the resources, such as water testing and expert advice, to take action.”

He said it also meant that they could focus on problems unique to their catchments. 

“Our problem is phosphate and runoff into streams, which is completely different from someone on the other side of the valley where they have high nitrate levels in streams. 

“Working together on a common problem has been really constructive,” Stuart said.

Alongside this, AIC contributed historical data to drive a risk-based modelling system. This showed the impact that potential mitigations, such as wetlands and bioreactors, could have on water quality. The final part of the project looked at developing and trialling financial incentivisation to encourage change and action ahead of regulatory framework.

As project partners, our land management advisors worked closely with both AIC and the farmers.

Northern water lead Andrew Arps said his team assisted with in-kind and professional advice, resulting in a relationship he described as “gold.”

Fine-tuning irrigation methods

Hennessy said once the catchment groups were formed, the next step was to get farmers looking at the big picture.

“We went through a process of going through what the problems and issues were in regard to water quality, along with potential solutions.”

The first cab off the rank was irrigation efficiency.

A report was produced for each farm, comparing their water use for the previous year against modelled data at the industry standard of 80 per cent irrigation efficiency. Modelling accounted for each farm’s soil type, rainfall data, evaporation, and transformation data.

This data was shared back with the groups, and in many cases, the figures were challenged, which Hennessy says was a good thing.

“Everyone believes they’re doing their best job, but the data was suggesting otherwise.

“Ultimately, it demonstrated how environmental issues are collective. There’s no ‘one person’ responsible. Everyone saw they contributed to the problem but also had a chance to contribute to the solution.”

Making best use of technology

The use of soil moisture probes was another early focus. The devices are a requirement of Farm Environment Plans, and for many, represented a ‘box ticking’ exercise, rather than a tool for helping them make informed irrigation decisions.

AIC arranged for suppliers of the technology to train the group on how to firstly set the probes correctly and then interpret what the probes were telling them.

Now, when the farmers order their water, they're provided with the previous weeks’ worth of irrigation data, so they can see where they’re sitting.

Hennessy said it all comes back to efficiency.

“At 80 per cent irrigation efficiency, we can take 100 tonne of nitrogen out of the rivers. At 90 per cent efficiency, we can take 200 tonne out.

“We’ve now set the standard at 90 per cent, and we’re starting to see better decisions being made. For example, when rainfall events are coming, people are turning off their irrigators beforehand, understanding that nitrogen only moves via water. They're also looking closely at nutrient management – managing what you put on your farm, when, and how.”

Capturing change from the air

In October 2023, high resolution photos were taken from the air to identify waterways and riparian planting opportunities. That led to another project involving the use of drones to home in on each waterway. The images were then GPS mapped.

Hennessy said they’ve now got a time/date stamp of all plantings and other improvements – and opportunities.

“Farmers are pretty humble, so when you ask them what they’ve done by way of plantings and such, they’ll say ‘not much’. But the photos paint a different picture. Up until then, we had no idea about some of the work they’d been doing.

“When we put the images up of work that had been done within their catchment, we just sat back while the famers poured over the images, looking with interest at the work their neighbours had done, for example.

“For some, it planted the seed of ‘well if they’re doing that on their farm, maybe I could too.’ It wasn’t us driving the behaviour change, it was coming from within.”

The drone images also enabled the groups to identify and address critical source and risk areas, such as a water trough or a gateway next to a stream. Hennessy said in some cases, significant improvements in water quality could be achieved by retiring certain land parcels or rethinking the placement of certain structures.

Land management advisors offer invaluable expertise

Hennessy said the groups relied heavily on the expertise of Andrew Arps and his land management advisors, and had also developed relationships with science and compliance staff.

“Farmers will ask me questions, and I’ll say ‘I don’t know the answer to that, but I’ve got a couple of good lads from Environment Canterbury who’ll be able to help’ – so we’ll bring them out to a farm and deal with whatever the issue may be.

“They'll prepare a plan for plantings – or what you can or can’t do in relation to streams and creeks. They give the farmers good clear, basic advice that they understand.

“It’s got to the stage now where I’ll mention the land management advisors, and the farmers will say ‘oh is that Sam and Andrew? Oh, they’re cool – yeah let’s get them out.”

Arps was quick to throw praise back at the group.

“The way they operate, it’s all done in a down-to-earth way yet is very professional and well organised.

“The time Mike took to establish the catchment groups is also evident – nothing has been rushed or forced, and it shows. It’s the best example of this type of collaboration that I've ever seen.”

Wetland trial for improving water quality

AIC was acutely aware that funding would eventually run dry. A sustainable financial component would need to be built into the project.

Hennessy said the goal was to find a process that farmers could understand, and that they could manage themselves to get a good outcome.

“A targeted levy could be one option. If farmers aren’t where they need to be, then there’ll be a cost, and that could help fund future projects.”

Testing key to tracking changes

Hennessy impresses that science remains at the crux of the groups’ work.

Improvements were being measured through testing, not modelling, with 100 water testing sites set up across the basin.

“Anything to do with water, we’re testing, and that’s being tracked so we can demonstrate improvements are being made.”

While promising evidence was emerging of changes in shallow groundwater – it’s still early days.

Hennessy likened the progress so far to being at the basecamp of Mt Everest.

“We’re succeeding in terms of education and delivery opportunities, but we’re still only at the start. The really exciting part though, is knowing these farmers are in it for the long game, and it's them driving the change.”

Learn more about the Amuri Basin Future Farming programme.