Two-thirds of country’s rivers are unswimmable with cow effluent and fertiliser run-off big contributing factors.

The New Zealand government has announced an ambitious plan to clean up the country’s freshwater sources, after years of pollution have made the majority of lakes and rivers unswimmable.

“Our rivers, lakes and wetlands are under serious threat after years of neglect. We can’t continue to go on like we are,” said environment minister David Parker, announcing the government’s action plan two years into its term.

“If we don’t fix things now they only get worse and will be more expensive to fix,” he said.

According to the environment ministry, two-thirds of all rivers are unswimmable and three-quarters of New Zealand’s native freshwater fish species are threatened with extinction.

Currently New Zealanders are encouraged to check their local council websites for public health warnings before heading out for a day on the water. Contaminated drinking water is not uncommon, with 5,000 people falling ill and four dying in 2016 after sheep faeces contaminated the Havelock North’s water supply 430km southeast of Auckland.

Under the new plans the government is aiming to “achieve a noticeable improvement in five years and restore our waterways within a generation”.

Immediate interim controls will be introduced on land intensification until councils around the country have freshwater protection plans in place by 2025. Higher water quality standards will be introduced for swimming spots, and farmers will be required to cease “risky farm practices” that pollute waterways, such as letting cows stray into waterways.

From mid next year changes such as new irrigation or conversion to dairying will only happen where there is evidence it will not increase pollution, and in catchments with high nitrate levels farmers would be required to take immediate action to reduce excessive leaching.

The government has set aside NZ$229m (US$145m) to help farmers transition to more environmentally friendly farming practices, but the measures have been met with uproar by the farming community, who say the Labour Coalition government has thrown the sector “under a tractor”.

Declining water quality has coincided with a boom in New Zealand’s dairy industry, the biggest exporter in the world. Cow effluent and fertiliser run-off are significant polluters of inland waterways, as are beef, sheep and deer farming. Deforestation and the extensive clearing of native wetlands have also played a significant role in the degradation of water quality.

According to the National Institute of Water and Atmospheric Science (Niwa), there is no doubt that the growth in pastoral farming, particularly dairy, is the main culprit for declining river water quality over the last 20 years.

But farmers say they’re being pushed out and their livelihoods overlooked.

“It becomes very hard to continue economically farming animals or growing vegetables under a regime like this,” Federated Farmers environment and water spokesperson, Chris Allen, said.

According to a recent poll, water pollution is now New Zealanders’ number one concern: with 82% of respondents saying they wanted tougher protections for waterways, ranking it as a priority above the housing crisis, the rising cost of living and child poverty.