A new report into the country's freshwater has found poor water quality is affecting people and the environment.
Our Freshwater 2023 is a joint report from the Ministry for Environment and StatsNZ that looks at the pressures on freshwater across the motu.
It found agriculture, forestry and urban expansion were big stress points, as were in-water activities like dams and stopbanks that break up ecosystems.
Climate change was also compounding the effects.
Of monitored lake sites, "45 percent worsened between 2011 and 2020, based on a nutrient and algae-level measure of ecosystem health," the report said.
It was "estimated 45 percent of New Zealand's total river length was not suitable for activities like swimming," according to models of campylobacter infection risk between 2016 and 2020.
And about 66 percent of freshwater native bird species were either threatened with extinction or at risk of becoming threatened in 2021.
This was the third report on freshwater in six years and Otago University's Marnie Prickett said not much had changed.
"These reports are essentially documenting the decline rather than driving us along the path of restoration and protection of what we love," she said.
Our freshwater 2023 was put together by the Ministry for the Environment and Statistics NZ. The key findings included:
- 36 percent of lake monitoring sites saw quality improve while 45 percent got worse between 2011 and 2020, based on a nutrient and algae-level measurements
- the total amount of nitrogen reaching rivers increased between 1995 and 2015, despite farmers' efforts, simply because the number of farms grew
- nearly half - 45 percent - of the length of our rivers is unsafe to swim in
- even more - 48 percent - is inaccessible to migratory fish
- by 2021, two-thirds of freshwater native bird species were either threatened with extinction or at risk of becoming threatened
- there were more than 4200 overflows due to wet weather, blockages and failures in the year to June 2021.
Nitrogen in rivers causing issue with nitrate in drinking water
The report estimated the total amount of nitrogen reaching rivers from farms has increased between 1995 and 2015, despite efforts to reduce fertiliser and keep stock out of waterways.
This was because the number of farms had also risen.
Dr Tim Chambers from the university's public health department said this then created a problem with nitrate in drinking water.
"Around half the monitored sites were either getting worse or showing no change. One in five of these sites [19 percent] would be failing the drinking water standards," he said.
"There was a town in Waimate that was unable to drink its drinking water because it breached the nitrate standard last year. And now they're having to undergo quite expensive treatment for that."
Seventeen breaches of safe nitrate levels were also reported from private water supplies last year, Chambers said.
And those are just the ones choosing to be tested - the true number was likely higher.
Sixty-eight percent of groundwater monitoring sites also failed to meet drinking water standards for E coli at least once over a four year period between 2014 and 2018.
Mike Smith of Ngāpuhi, Ngāti Kahu is co-chair of the climate directorate for the National Iwi Chairs Forum.
He said consequences of inaction were already being felt by people and the environment.
"The subsequent threat to public health [from poor quality drinking water] in terms of blue baby syndrome and heightened risk of colorectal cancers [from excess nitrates]."
"Then there's what we saw in the Hawke's Bay with camplyobacter coming off the farms and how 5000 people fell down, 13 of which never got back up," Smith said.
The report found there were 4200 wastewater overflows reported over 12 months between July 2020 and June 2021.
Smith said action needed to be taken to address the pressures instead of endless report releases.
"If the average New Zealander could see... the carnage that was going on in our water space, people would really understand the depth and the need to clean this up," he said.
"We're in the early stages of a climate crisis that we can all see is happening around us... Kaitaia and Kaipara in the past few years have come within days of not having an adequate water supply."
He wanted to see political appetite for action.
Prickett said the government needed to stop chronically underfunding water infrastructure and monitoring.
"It's kind of random. Often councils are reporting on themselves and their own activity. They've got a whole lot of different political motivations for why they might monitor somewhere and not somewhere else," she said.
"We need a reporting system that is independent, that is high quality and continually producing data."
Three waters reforms would help and there had been too much misinformation and scaremongering around current proposals, she believed.
"What it comes down to really fundamentally is how good is the water coming through your taps?" Prickett said.
"How safe are the streams and the environment and the beaches around you to swim and have fun in? And how safe are our urban environments in terms of flooding?"
Report 'interesting if demoralising'
Ministry for the Environment deputy secretary for evidence Natasha Lewis told Midday Report that the report showed the country's freshwater environments were under pressure.
"That's our wetlands, our lakes, our rivers and our groundwater - and that's affecting our quality of life and the things that are important to us.
"This report highlights three substantial pressures... it's the activities we undertake on our land, it's agriculture, it's forestry, it's urban expansion, as well as activities we undertake in water - so, dams and stopbanks affecting fish passage. And then of course the compounding impact of climate change."
While NZ Freshwater Sciences Society president Jenny Webster-Brown said there was "little good news" in the report, calling it "interesting, if demoralising".
"Such a dismal state of the environment assessment should be able to galvanise the stewards of our environment into action. We know what needs to be done to reverse these trends. I fear this report will not do this," she said, criticising its comparatively short length and lack of "informative graphs and graphics".
Victoria University of Wellington researcher Mike Joy, whose work documenting the decline of freshwater systems has been making headlines here and overseas for more than a decade, said the report "unflinchingly identifies the appalling state of lowland freshwaters of Aotearoa" with "honest and direct reporting".
He criticised it for using what he called out-of-date data and small sample sizes in places, and using "short time-period data" which could "give the false impression of no change", when longer-term measurements show degradation more clearly.