Farmers should be given a "period of grace" to fence off waterways badly polluted by livestock, says Green Party co-leader Jeanette Fitzsimons.
The recently released State of the Environment report showed farmers are causing the worst environmental problems in New Zealand: soil degradation, water degradation and greenhouse gasesfrom livestock.
Ms Fitzsimons said farmers could not continue to pollute, and unless there was urgent action, New Zealand risked losing its clean, green image.
However, the rule could be phased in for sheep and beef farmers over a longer period of time.
"Give them a period of grace. If they show willing and make a start, give them time to finish - say five years."
Her comments came after Environment Waikato sent 2000 letters to farmers in the central North Island telling them they have waterways that must be fenced off.
Dry-stock farmers said the rule was impractical and a big expense, especially at a time when their returns were particularly low.
Environment Waikato chairman Peter Buckley said sheep and beef farmers had a problem with the rules, which would be difficult to enforce and could be subject to change.
Ms Fitzsimons said dry-stock farmers were certainly in a difficult financial situation, but the issue of water quality had to be addressed urgently.
The regional council was to be congratulated for sending out the letters but Mr Buckley's comments sent a mixed message, she said. "They need to be really clear. A rule is a rule."
Ms Fitzsimons said the dairy industry's clean-stream accord was having some effect and was a good starting point. But Federated Farmers' goal of 10 per cent improvement in 10 years was "pitiful".
The central Government should support regional councils by developing a national policy statement and national environmental standards for them to work to.
She said Environment Waikato's 35 per cent subsidy on fencing and plants was probably generous enough. Farmers could make up the difference in kind through doing the fencing and planting themselves.
"I'm not saying their time's not worth anything.
"But they can do the work when they've got time and there's virtually no financial cost."
Environment Waikato's Coromandel representative Simon Friar said the rule needed to be reviewed to determine whether it was appropriate in all circumstances.
