The NSW government has struck a compromise position by allowing wild horses to remain in around one-third of the Kosciuszko National Park under a new draft plan released on Friday.
The plan will require the current wild horse population of the park - last year estimated at just under 15,000 - to be culled or rehomed so as to achieve a population target of 3000 by June 30, 2027.
Under the plan, three broad zones will be established with the horses permitted in 32 per cent of the national park, 47 per cent to be kept free of the horses, and the animals to be removed from the remaining 21 per cent.
NSW Environment Minister Matt Kean described the draft plan as striking "the right balance between protecting the fragile alpine ecosystems and recognising the cultural heritage values of the wild horses".
"I recognise there are very strong and diverse views on this issue but at the heart of these views is a common desire to sustainably manage the park for the future," he said.
"For too long we have been deadlocked on this issue and unable to find a way forward. This has served no one's interest, least of all the environment.
"This draft plan provides protections for one of the nation's most precious environments and all of the animals that call it home, but more importantly it provides that much-needed way forward."
He said the land where the horses would be allowed to remain had the "strongest links to wild horse heritage values and are areas with links to historic pastoralism, brumby running and include wild horses derived from historic pastoral populations (eg, the Kiandra greys)".
The plan's intent to is to keep the horses away from the main alpine range but the chief executive officer of the Invasive Species Council, Andrew Cox, said that would be a very challenging element to manage "given that they [the NSW government] have been unable to manage the population to date".
Horses would continue to roam those areas where endangered and at-risk species existed, which he said was "completely contrary to the intention of establishing the park in the first place, to protect these threatened species".
"First of all we have to get those horse numbers down because for the past 18 years the numbers have continued to climb," Mr Cox said.
"This plan locks in that environmental damage and locks in the trajectory for those threatened species which will quite soon disappear from the park.
"There will need to be active and ongoing management, even to contain a smaller number of horses. This will come at great cost and significant management headaches."
The issue of wild horses within the national park has been a contentious one for decades - but only in Victoria and NSW. The ACT government has always opposed wild horses in the park, not just because of the threat to endangered species, but moreover the damage that their heavy hooves cause to the delicate high alpine spagnum mosses, so vital to preserving the integrity of the ACT's water catchment.
Jill Pickering from the Australian Brumby Alliance said the group had not yet had the opportunity to meet to discuss the NSW draft plan but believed a compromise had been struck which at least would preserve the brumby heritage.
"The alliance had always been quite firm that around 4000 was the most viable [herd] number, so I suspect there will be some discussion to come on that," Ms Pickering said.
The draft plan will go up for public comment until November 2.