The ACT government will refer both of its prospective light rail stage two routes to the federal Environment Minister, keeping both options alive while it waits for a report back from the Commonwealth on the pathway to getting the project approved.
The Barr government will decide after next year's federal election whether to pursue its chosen route from Civic to Woden through Barton or go via State Circle to avoid time delays and cost blowouts in getting the project approved.
Chief Minister Andrew Barr described State Circle as a "compromise" route, as it sat between two options which were put out for public consultation last year, the Barton route - which cuts through the Parliamentary Triangle - and the more direct Capital Circle route.
State Circle was also illuminated as the path of least resistance to getting the green-light for the project, as the alignment is already marked as an inter-town public transport route in the National Capital Plan.
However an ACT government spokeswoman said the government would lodge an Environment Protection and Biodiversity Conservation (EPBC) Referral that kept both the Barton and State Circle alignment options open, while at the same time taking a closer look at the latter route.
"There are challenges and opportunities in any route option, including the right balance between, for example, patronage, cost, travel time, location of stops, heritage, technical feasibility, planning approvals and connection with other transport options, including the city wide light rail network," the spokeswoman said.
"Some of the early issues identified with a State Circle option included the impact on the existing road network, gradients, heritage considerations, and access to employment zones.
"These issues associated with the State Circle option are balanced by the potential to achieve significantly speedier Commonwealth approval processes.
"This is an important project for the residents of the inner south and Woden, and will create a north-south public transport spine for our city. We want to deliver on this project as soon as possible, and if that means that we need to consider a different route to avoid time-consuming Commonwealth approvals, we will do so."
The Environment Protection and Biodiversity Conservation Act requires ministerial approval on any action that is likely to have a significant impact on areas of national environmental significance.
After the referral, the environment minister has 20 days to decide if a formal environmental impact assessment is required.
Initial advice to the ACT government suggests a formal assessment will be needed.
The ACT government will then prepare a draft environmental impact statement - based on guidelines issued by the Environment Department for the project - which will be released for public comment.
A final environmental impact statement will then be assessed by the department, which will provide a recommendation report to the minister.
The minister must then decide whether to approve the project within 40 days of receiving the final environmental impact statement.
The ACT government is planning on filing a single environmental impact statement to address the requirements of both territory and Commonwealth laws.
The territory must then seek a works approval from the National Capital Authority, which requires it to prove the project demonstrates respect for the key elements of the Griffins’ formally adopted plan for Canberra and contributes positively to the overall composition, symbolism and dignity of the national capital.
NCA chief executive Sally Barnes told a federal parliamentary hearing on Thursday the agency was yet to be briefed on the State Circle route.
"We're waiting to hear, ready to help and to provide advice on what would be required to move forward on either route," Ms Barnes said.
Ms Barnes said a heritage impact assessment of both routes was one of the "key underpinnings" required by the NCA.
"We’ve had external advice both to the NCA and ... the board that says the documentation that’s in the public domain or that we’ve received so far is insufficient for us to even consider making a decision on either route at this stage," Ms Barnes said.
However those heritage assessments are unlikely to take place until the federal government makes its formal response to the joint standing committee report on the parliamentary approvals from October.
A spokesman for Assistant Minister for Regional Development and Territories Sussan Ley said the federal government was still considering the report and was working to release a response "as soon as it is possible to do so".
In the meantime, the ACT government spokeswoman said they were still working on elements of the project, including early planning work and business case activities for works on the Woden Bus Interchange and surrounding road network, park and ride facilities and the Yarra Glen roundabout and intersections.