However, the ACT Government, Land Development Agency and Riverview Group proposal to relaunch the falls within a conservation management corridor has drawn criticism from community groups angling for the site's environmental and indigenous heritage landmarks to become the center-piece of a national park.

Stage one of the project will see 354 dwellings built on ACT land near Strathnairn and the start of the 577-hectare conservation corridor earmarked for the western edge of the 1600-hectare site.

The fate of the 600 hectares on the NSW side hinges on whether the Yass Valley Council decide to rezone the land from rural to urban use when the issue is tabled before mid-year.

Riverview Group has to demonstrate to ACT Treasury and Yass Valley Council their plan to return one per cent of land sales value for each block to a non-profit trust would create a funding base to run its operations in perpetuity.

Conservation advisor Jason Cummings, who has been instrumental in the management of Mulligans Flat and Jerrabomberra Wetlands, said when created the trust would own the land and be constrained by its constitution to implement a management plan there.

"Clearly we are not setting it up to run out of money but the land that goes into the trust could only ever be transferred to a bush heritage, or a greening Australia or a similar not-for-profit organisation," he said.

The vision is for the trust to re-establish walking trails, build a tourist centre, viewing platforms and public river recreation areas as well as oversee fox and feral animal control plans to support native flora and fauna.

Ginninderra Falls Association president Chris Watson is staunchly opposed to the relatively narrow buffer between development on the Ginninderra Creek side fearing it encroaches on the river corridor.

He feels anything short of national park protection would be a "furphy" and may jeopardise the rich ecology and cultural value of the waterways known to host significant indigenous ceremonial and male initiation sites.

"Thinking because it is in private hands they can do what they want is pathetic, tragic," Dr Watson said.

"It is the Canberra people that have to agitate to have it set aside. We have to go for broke. This is a vital area. Aboriginal area has got to be restored, it has threatened species, wonderful views and both gorges Murrumbidgee and Ginninderra."

Despite such calls neither the ACT nor NSW Governments have considered the area a priority for national park status.

The NSW Office of Environment and Heritage stated National Parks and Wildlife Services prioritized land purchases from willing sellers and that "establishment and management of the site would be cost-prohibitive".

Riverview Group director David Maxwell commissioned a report to determine whether the land warranted national park protection and said the site's International Union for Conservation of Nature category four ranking suggested it did not qualify and led to the conservation trust concept.

Ngunawal elder Wally Bell is a knowledge holder who has been widely consulted during the cultural heritage assessment of the cross-border site.

He'd like to see the top of the falls, which many Canberrans have scrambled across in summers gone by, become a no-go zone and see land protections established for rock shelters and various artifact scatter sites.

"The cultural significance of the whole development area is pretty high," he said. "You have to understand for my people to survive for thousands of years we had to navigate through the landscape and waterways were our pathways. Most of our sites are pretty close to the Ginninderra Creek zone."

Mr Bell said the width of the buffer zone on the Ginninderra Creek side was still being discussed and three cultural heritage reports would inform Yass Valley Councillors considerations and future planning setbacks and site lines restrictions

He was pleased Riverview Group director David Maxwell had agreed to accept any recommendations from the studies and to adjust the corridor boundary if recommended.

"David and I have been talking about these things for ages and he is really accommodating and actually listening which is something you don't find a lot," he said.

Mr Bell was "all for" the creation of a trust and hoped it would support the upkeep of spiritual sites and enable indigenous community members to host 'walk and talks' to share knowledge about cultural lore and connection to country.

"Development is not going to take place on the NSW side for the next 30 years so we have a bit of time to work on it," he said.

Striking a balance between sharing the rich cultural sites without exposing them to the risk of damage or defacement was crucial.

"We want to make sure the rezoning is not going to have any detrimental effect on the protection of cultural heritage within that area."