Farmers remain to be convinced about the merits of the Manawatu-Whanganui regional council's One Plan which was approved this week.
But the Fish and Game organisation sees it as a landmark in environmental protection.
The One Plan replaces six separate ones and is designed to manage natural resources in the North Island region.
The main preoccupation for farmers and growers is nutrient management rules setting targets on a catchment-by-catchment basis for limiting nitrogen leaching.
A farming spokesperson said the plan would need tweaking to line up with new national water standards and other legislation.
But Fish and Game's environmental manager Corina Jordan said the One Plan was nationally important because it set a precedent.
"It sets up a framework which clearly understands the link between land use, in particular primary production, and the health of fresh water. The One Plan recognises the impact that primary production land uses have on fresh water and so it sets out a management or regulatory framework which ensures that land use is sustainable and its imapcts on the environment, on fresh water, are reduced over time," she said.
"In doing that, it sets limits for water quality which protects life supporting capacity or the eco-system health of fresh water, and that's a little bit different from what we are seeing around the country with other regional councils that are maybe looking at setting limits for nitrogen in particular, at toxicity levels, rather than at levels that protect the actual health of fresh water.
"So we fully endorse the approach taken by the regional council and are hoping that other regional councils will adopt similar approaches around the country."
The Horizons One Plan would be operating from 19 December.