The ACT government's "develop everywhere possible" mentality is jeopardising Indigenous cultural and natural sites near the Ginninderry development, according to submissions on the project.
The public was invited to make submissions with Yass Valley council on Parkwood, the NSW-side of the cross-border Ginninderry development in Belconnen.
Many of the submissions raised concerns about the need to protect the sites.
It comes as the Yass Valley Council received a petition last month calling for more efforts to conserve Ginninderra's Indigenous sites.
When completed, Parkwood will see 5000 new homes built along the Ginninderra corridor, home to the Ginninderra Falls and vulnerable native wildlife.
Ginninderry will add 11,500 new homes to the capital, including those across the border in Parkwood.
Developers Riverview have proposed a set conservation corridor along the nearby river, but conservationists argue it's too small and only limits the reserve to steep slopes, problematic for biodiversity in the area.
One submission from the Ginninderra Catchment Group said a proposed rezoning of 35 hectares of land from environmentally reserved to general residential should not go ahead.
Instead the site should be managed to protect the nearby falls and Aboriginal cultural sites.
Riverview's proposal documents said there were five major Aboriginal artefact sites in the area as well as scarred trees and burial grounds.
The NSW Office of Environment and Heritage, in their submission, pointed to the "highly valued" Aboriginal cultural sites at Ginninderra.
The office's south-east conservation director Michael Saxon said the development's heritage clauses - laws protecting heritage status - would need to be consistent with any future Aboriginal Heritage Management Plan.
"It is in the interest of the proponent to ensure that all reasonable precautions are taken to prevent the occurrence of harm to Aboriginal objects," Mr Saxon said.
"Further consideration should also be given to avoiding inadvertent impacts to .... Ginninderra Falls as a result of increased visitation."
Mr Saxon also raised concerns about unclear plans to develop a 10 hectare parcel of land in Parkwood, which he said the office "does not support".
"We note that the 10 [hectare] contains an area of known pink tailed worm lizard habitat, the future management of this site has not been clearly articulated in the documentation," Mr Saxon said.
He said it was important to clarify what Riverview would do with this parcel. If developed it would impact the conservation corridor and environment offsetting calculations made for the development.
When contacted by The Canberra Times, Riverview director David Maxwell said this parcel currently had the potential to be subdivided but would "ultimately form part of the conservation corridor when the site is redeveloped".
Mr Saxon also warned the flood management plan was unclear and needed to be clarified. He said the document developers had relied on weren't written with land use in mind.
Mr Maxwell said "appropriate flood investigation to address the items raised has been provided to [the office]".
When suburban development minister Yvette Berry was contacted for comment, a government spokeswoman said Ginninderra Falls was a matter for the NSW government as it was located in NSW.
Riverview is a joint venture between the ACT government and developers, the Corkhill Brothers, to develop Ginninderry.
Both Ms Berry's spokeswoman and Mr Maxwell pointed to the founding of the Ginninderry Aboriginal Advisory Group as a sign of the development's commitment to protecting Indigenous values.
One submission from the public said the ACT government needed to reject any development at Ginninderry until more research could be done on "buffer zones" between the conservation areas and the residential areas.
"After years of academic research and public consultations, we are still left with a 'develop everywhere possible' mentality putting only steep slopes into a conservation reserve," the submission said.
The submission said the current buffer zones wouldn't protect biodiversity and Aboriginal heritage.
"It is not even enough for tourists to enjoy what's left," it said.
One submission said it was "an outrage" to place 5000 houses in the area.
"How dare [Yass Valley council] even consider ruining this lovely area," it said.
In his submission, Chief Minister Andrew Barr reiterated his desire for the ACT border to be moved to encompass Parkwood.
"This has been the consistent position of the ACT government," Mr Barr said.
It has been previously suggested that if the border cannot be moved, the majority of Parkwood's services would be provided by Canberra. ACT law would also potentially apply to Parkwood residents, who would be unable to vote in ACT elections.
NSW Fire and Rescue and NSW Ambulance both said emergency services were best provided by the ACT.
Both said because Parkwood was landlocked, access would need services to travel into the capital before reaching Parkwood.
Parkwood is not set to break ground until 2034.
Mr Maxwell said Riverview would provide a final response to all matters raised by the submissions to the Yass Valley council.
"The proposal will then be considered by the council in the coming months," Mr Maxwell said.