The Birrigai Outdoor School in the Tidbinbilla Nature Reserve was scoped out as a quarantine site for year 11 and 12 students from China who wanted to return to Canberra for study, according to the documents.

In a February 27 email from the ACT chief health officer's office to Chief Minister Andrew Barr's office, health officials said work was under way to plan for accommodation, support services and transport of students at the site.

The emails said it was estimated up to 60 students from China were expected to return to the ACT for the school year.

However, just 15 of those students were expected to be quarantined at Birrigai.

Birrigai Outdoor School has been used primarily for school camps and can fit up to 200 students.

Health officials had been working on a way to get Chinese students back to Canberra safely following a decision by the federal government to suspend travel between China and Australia.

At that point, the ACT had no cases of coronavirus with just 101 tests conducted in the territory.

The Birrigai plan was floated a month before broader COVID-19 lockdown measures came into effect across the ACT and the rest of the country.

An ACT government spokesman said Birrigai had been considered as a location before the government declared a public health emergency, leading to the proposal being scrapped.

"Protocols for effective quarantine changed and the site was no longer viable," the spokesman said.

"There are no plans to utilise the facility in response to COVID-19 at this time.

"The ACT's home and hotel quarantine framework has proven successful in protecting the territory from COVID-19."

The documents also revealed discussions within ACT health about what trigger points were needed to move Canberra to some of the first stages of lockdown measures.

In an email dated March 26, just days after restaurants and cafes were ordered to close, ACT chief health officer Dr Kerryn Coleman said she did not want to risk alarm in Canberra by implementing restrictions based on the virus situation in other states and territories.

"For ACT, NSW will reach [trigger point] well before we will, however practically implementing a different timing will be very difficult," Dr Coleman said.

"Therefore, if we implement based on NSW situation, the health outcome will be better but we risk community concern regarding unnecessary measures as we don't see the changes here."

The email said the measure of the impact of coronavirus on Canberra's health system was likely to be too late to trigger the next stage of restrictions.

Criteria being looked at to consider further changes at the time was the measure of community transmission and how well social distancing was working.