Farmers say the most draconian of the government's proposals to restore the quality of the nation's waterways would effectively close the farm gate in some regions.
Under the proposals, there would be tighter restrictions on intensification, meaning farmers would need to prove it wouldn't add to pollution.
All farms would need to have management plans addressing water quality. Some could face nitrate caps - meaning they would need to take immediate action to reduce excessive leaching.
The government is also proposing extensive fencing requirements and standards around winter grazing.
RNZ reporter Robin Martin has more.