Farmers say they're not the only ones who have to make changes to protect the environment

Greenpeace says the new Environment Aotearoa 2019 report shows dairy is the country's "dirtiest industry".

The report highlights the national dairy herd increased by 70 per cent between 1994 and 2017, while numbers of sheep and beef cattle declined.

Federated Farmers environment spokesperson, Chris Allen says they've got a job to do when it comes to waterways that go through farmland.

But he says people shouldn't throw rocks in glass houses, as there are also challenges in urban waterways.