The Labour Party wants to ban farmers from intensifying their operations unless they have a resource consent.
The party today released its new freshwater policy, which it said would improve water quality within five years and make rivers and lakes "genuinely swimmable".
It said within a generation even the most grossly polluted rivers and lakes would be cleaned up.
The 12-point plan includes requiring all intensively stocked farmland near waterways to be fenced within five years, introducing a new National Policy Statement, and taking action against controversial farming practices such as so-called spray and pray.
Labour water spokesperson David Parker said what was needed were better rules and better regulation.
"It doesn't cost money to clean up rivers, all you need to do is to stop pollution being put in them and they clean up themselves."
Mr Parker said Labour would also give either the Ministry of Environment or the Environmental Protection Authority more resources to prosecute those who breached the Resource Management Act.
Regional councils would also be targeted by the Labour policy, with new rules requiring them to report annually on whether rules within their region were adequate to protect waterways. The Audit Office would check every year whether those councils were properly carrying out their legal responsibilities.
The plan follows the National Party government's Clean Water Package, announced in February, which would aim to make 90 percent of the country's waterways swimmable by 2040.
Farmers already making changes - Federated Farmers
Federated Farmers environment spokesperson Chris Allan said Labour's plan lacked a balanced approach and could undermine regional economies.
There were numerous examples of farmers and their communities working together to improve waterways, he said.
"Last night's Green Ribbon Awards in Wellington, where two farmer-led environment projects were honoured, demonstrates this," Mr Allan said.
He said if Labour formed the next government, Federated Farmers would welcome the opportunity to work with them on finding sensible, practical and affordable solutions to water quality.