'Sobering reading': Waterways worsening around the country, report reveals

The health of a large portion of the country's waterways is worsening, a new freshwater report says.

The Our Freshwater 2026 report, commissioned by the Ministry for the Environment and Stats NZ, was released on Thursday shining a light on the condition of the country's rivers, lakes, wetlands and aquifers.

A central focus of the report was on groundwater.

Recent figures showed many rivers and groundwaters were affected by pathogens or nitrate levels that could pose risks to human health.

"Pressures from land use, contamination, water abstraction and climate change are altering the quality and movement of water across rivers, lakes, wetlands and aquifers. These changes affect drinking water security, ecosystem health, recreation, cultural practices and economic activity in many regions," the report said.

Of the 998 groundwater-monitoring sites, 45 percent had E.coli concentrations above the maximum acceptable levels for drinking water at least once between 2019 and 2024.

Twelve percent had nitrate levels above acceptable levels at least once.

Improvements were reported in other areas, including phosphorus levels in rivers and lakes, and the visual clarity of most monitored rivers.

"Together, the updated indicators show that while some aspects of freshwater quality and ecosystem health are good and improving, others are deteriorating. This reinforces the need to

view freshwater as an interconnected system where multiple pressures accumulate and interact over time," the report said.

Nitrate levels have also worsened at more groundwater sites.

The report said it was "very likely" the levels worsened at 39 percent of monitored sites and improved at 26 percent of sites.

Between 2020 and 2024, almost half of New Zealand's total river length was deemed unsafe for recreational activities, including swimming.

"E.coli concentrations tended to be higher at river monitoring sites with higher proportions of human-modified land cover (urban, agricultural and plantation forest) in the upstream catchment area."

More than half of rivers were showing organic pollution and nutrient enrichment between 2020 and 2024.

'Sobering reading' - reaction from experts

Waikato University associate professor in biodiversity and ecology Nicholas Ling said although there had been improvements, most parameters showed either little gains or a worsening of conditions.

"Today's release of the latest report on the state of our freshwater makes for sobering reading.

"Of particular concern is continued significant deterioration in the state of our lakes, wetlands and groundwaters. Any slight improvements in the nutrient status of rivers does not yet translate to improvements in ecological conditions, with more than half of all river length indicating conditions of moderate to severe organic pollution."

Canterbury University professor of freshwater ecology Angus McIntosh said the report painted a bleak and sad picture of freshwater health.

"The dire state of freshwater health won't be a surprise to those with connections to a lowland river or lake, and the report illustrates those close health, cultural, economic and recreational ties.

"Some water quality parameters are going in the right direction, and substantial efforts are being made in some places, but much more widespread progress in dealing with water quality and quantity problems is needed before measures of freshwater life will improve."

'Breaking point'

Forest & Bird said the report had shown New Zealand's freshwater was at a "breaking point" with polluted rivers, unsafe swimming spots and contaminated groundwater.

The findings were a red flag for anyone who cared about safe drinking water and healthy rivers, Forest & Bird's regional conservation manager for Canterbury and the West Coast Nicky Snoyink said.

"The report masks that reduced flows from irrigation have devastating impacts on freshwater ecosystems. Then the land use that irrigation allows - such as intensive dairy farming, a major consumer of freshwater allocated for use - can return that water to the ecosystem in a worse state.

"For families, iwi, and communities, this is about more than numbers. It's why warning signs are posted at swimming holes and why gathering kai food from rivers and lakes is no longer safe."

Snoyink noted the report made no mention of the need to change current land use to restore freshwater and adapt to climate change.

"We're calling on decision makers to use this evidence to put in place stronger limits on pollution, and create land-use rules that protect the health of rivers, lakes, and aquifers."

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