The Government says a report paints an encouraging picture of the country's waterways, though more work needs to be done.
The Ministry for the Environment on Monday released updates on river conditions and swimming suitability.
Environment Minister Amy Adams said the report shows that 88% of coastal swimming sites and 56% of fresh water sites are safe for swimming.
Ms Adams said there are areas of concern but it is a long term project to improve all water quality.
However, the Green Party said 61% of recreational river sites are unsafe and the Government's freshwater management policy will only make things worse.
The Greens said the policy will allow more large-scale irrigation projects.