‘‘Our Freshwater 2026’’, published yesterday by the Ministry for the Environment and Stats NZ, blames farm runoff, including from dairy conversions, for nitrate pollution in groundwater exacerbated by ‘‘stocking rates, fertiliser use, irrigation and changes to riparian vegetation or stream channels’’.
Groundwater contributes about 80% of many rivers’ flow and is a major source of drinking water.
Nitrate increased quickly in groundwater in some areas between 2004 and 2024, the report said, notably in Canterbury.
However, Southland was flagged in the top four areas with likely high ‘‘pressure’’ on water resources and irrigation the largest consented water use. Nitrate levels spiked above the safe maximum allowable level in Gore’s water supply last year.
Southland also had the biggest loss of wetlands, which cleans water and preserves biodiversity.
Greenpeace freshwater campaigner Will Appelbe said an Environment Southland (ES) report on nitrate contamination ‘‘has been sitting on desks since January and we’ve yet to see the council do much about it. Frankly, the time for action is long overdue’’.
The ministry’s report had indicated individual farmers had made strides in reducing pollution, but gains were ‘‘swallowed by the sheer scale of dairy intensification, especially for nitrogen’’.
‘‘Southland is one of the areas most impacted, and the regional council must take some responsibility and accountability.’’
Forest & Bird Otago and Southland regional conservation manager Chelsea McGaw said ES and the Otago Regional Council (ORC) should stop ‘‘sitting on their hands and blaming government reform for inaction’’.
ES had been criticised in the High Court last year for failing to monitor and prevent loss of wetlands.
While the ORC had tried to update freshwater rules, but been foiled by government policy changes, Ms McGaw felt much more could be done.
University of Otago ecologist and inaugural chairman in freshwater sciences Prof Ross Thompson peer reviewed the ministry’s report and said it was ‘‘impressive’’ in scientific rigour and showed ‘‘declines in water quality’’.
‘‘The story across much of Otago and Southland is business as usual. We can see clear signs of degradation in our rivers and lakes as a consequence of farming and, in particular, loss of wetlands, which are the kidneys of our landscape. Of most concern is where we are seeing large-scale landscape change — urbanisation, dairy conversions and forestry conversions, which is generating a signature of ecological stress.’’
Prof Thompson said meeting the water quality challenge required a combination of regulatory consideration of land use and also ‘‘desperately needed’’ research-based improvements to on-farm practices due to the ‘‘huge expansion’’ of dairy farm conversions already.
‘‘Regardless of the future of regional councils there is going to have to be government management of these problems. The market is not going to fix this.’’
ES general manager strategy and regulations Hayley Fitchett said the council was ‘‘aware’’ of the ministry’s report and councillors recognised nitrate contamination was a ‘‘complex issue that requires sustained and co-ordinated action across multiple levels of government, the agricultural sector, and local communities’’.
The ORC was unable to respond by deadline.
