The latest report on the state of New Zealand’s freshwater has highlighted that there is still a lot of work to be done by the dairy industry to mitigate its footprint.
The industry is dealing with an issue that has been decades in the making after years of land use change intensification, DairyNZ general manager of sustainable dairy David Burger said.
The Ministry for the Environment (MfE) report, Our Freshwater 2023, underlines the pressure the country’s freshwater is under, blaming land-based activities for much of the damage.
None of its findings surprise Burger, he said.
New Zealand has a water quality challenge, and the industry is committed to addressing it.
“We know the job is not done and we know it will require further efforts to get there and we’re committed to that.”
Burger said the report uses an assessment framework based on a water quality state that existed before humans arrived.
“It sets the bar very high, especially in catchments where there has been a lot of land use change.
“If we are assessing it at a pre-human state, of course we expect a lot of sites across New Zealand to be degraded.”
In comparison, the Land, Air and Water Aotearoa (LAWA) database, which uses national standards to classify its water quality (Bands A-D), shows that some sites have had water quality improvements across a range of metrics including nitrates, phosphorus and clarity.
This is data collected by regional councils across the country that is collated by the Cawthron Institute.
On the same day that the MfE’s report came out, LAWA data showed that 80% of sites across New Zealand are suitable for swimming.
Both used the same data set, but interpreted it against different things, he said.
“LAWA is interpreting the data against national environmental standards for freshwater – the national bottom lines. The MfE environment report from last week compares that data against water, a quality state expected to be in the absence of human disturbance.”
Burger emphasised this was not an excuse not to act on water quality and there are lots of sites within the LAWA data that highlight where standards are not being met, and the industry is continuing on that path.
Nor did he downplay the impact of years of land use intensification, when the industry grew from 1995-2014 with 40% more dairy land use, which affected water quality.
The MfE report is not all bad news. It acknowledges the work many individual farms have done to improve water quality, particularly around effluent and fertiliser management, stock exclusion and riparian planting.
“Overall, our phosphorus load is 25% lower over that same time period and the nitrogen load on individual farms would have been much higher. Of course the total load of N is much higher because we also increased dairy land area by 40% over that same timeframe.”
Much of the on-farm work is voluntary and is being done by farmers to stay ahead of regulations, he said. There are signs that some of the trends are turning around – “there’s a big improvement in water clarity, for example”.
Other indicators, such as N levels, will take longer to turn around because of the lag between on-farm action and groundwater lag. That time lag could be years, he said.
Cow numbers have also stabilized and are declining. The annual dairy statistics for the 2021-2022 season show that overall, numbers dropped 1.26% to 4.84 million.
Burger said the work done by DairyNZ and science bodies such as AgResearch is making a difference, pointing to the different environmental standards now in place compared to 20 years ago.
“We now have around 7000 farm environmental plans across the dairy sector – that’s about 65%. That’s been huge.”
These have helped farmers identify both environmental risks and actions they can take to improve their footprint. A lot of that work has been driven by catchment groups and the wider dairy sector.
“There’s a lot of great work happening to turn those trends around.”
He believes the work is acknowledged by the MfE – but getting that recognition from the wider public is a “continuous journey”.