Federated Farmers believe the ship is turning on river water quality.

A 10-year analysis by Land, Air, Water Aotearoa shows measures such as E.coli, nitrogen and water clarity are getting better in more cases than they're getting worse.

Federated Farmers environment spokesman Chris Allen told Mike Hosking around 90 percent of rivers are showing good data, and the focus now is on getting that to 100 percent.

"There's other areas where we cant swim. We appreciate that not every waterway is meeting those expectations. The trend is turning around, and one day, we will be able to meet those expectations."

The new analysis relates to nearly 1500 regularly monitored freshwater sites.

LISTEN TO CHRIS ALLEN TALK WITH MIKE HOSKING