A Government report aimed at cracking down on water-polluting farmers has been called a "recipe for more dirty water", with Opposition parties saying the bar has been set too low and the schedule is too slow.
Environment Minister Nick Smith on Saturday announced a set of proposed new rules for national water management, including changes aimed at cracking down on farm animals in waterways with nationwide fencing standards and fines.
Dr Smith said inconsistencies between the ways councils handled regulations made the current regime confusing and some councils were simply failing.
"The problem with each regional council making their own rules is that most have not done so, and for those that do, enforcement is cumbersome and expensive," he said.
But the changes proposed in the "next steps for freshwater" consultation paper would only affect pig farms by 2017, with all other stock being phased in by 2030.
Dr Smith said it was hoped fines - of $100 per animal to a maximum $2000 - for offending farmers would curb the problem.
Labour's environment spokesman, David Parker, said the timeline was too long and the changes would only allow waterways to get worse.
"Despite the explosion in dairy beef and other beef cattle numbers, National's plan does not exclude them from lowland rivers until 2025 and from rolling country until 2030," he said.
The report also proposes retaining the current cleanliness standard requiring it to be "wade-able" and "boatable", rather than swimmable.
The Green Party's water spokeswoman, Catherine Delahunty, said that would disappoint swimmers around the country and was a "recipe for more dirty water".
"The consultation document may sound like a step forward but it is in a context of weak overall standards which do nothing to protect the birth right of our children to swim in clean water," she said.
The consultation papers author's said it was unrealistic to set the standard at clean enough for swimming.
"Almost all rivers during peak flows will have contaminants that exceed safe swimming levels. Nor would all water bodies have been swimmable prior to settlement and development," they said.
"The costs of achieving the high standard of water quality required for swimming in some water bodies in both urban and rural areas would be prohibitive."
The report looks at a broad range of issues and changes, including how to fund investment in fresh water, iwi rights in planning and consent processes and improving water use efficiency.
A consultation period on the changes goes until April 22 and will include a series of meetings.