The Government is putting $44 million into projects to clean up 100 rivers and lakes around the country.
The money will be given in grants to councils, which will also contribute to the clean up.
"It will fund the fencing of waterways from farm animals, planting along streams, development of wetlands, sewage reticulation and water storage," said Environment Minister Nick Smith.
"There are also initiatives in the package to eradicate water weeds, remove water weeds, remove pest fish and retire marginal land adjacent to waterways."
The grants are the first tranche of funding from the $100m Freshwater Improvement Fund announced last year.
Labour is due on Wednesday to announce an environment police, expected to centre on freshwater quality.
Dr Smith denied he was trying to steal its thunder and said the Government's measures had been in the pipeline for many months.