Updated design plans for stage one of the F6 extension show the second stage will branch off from the twin tunnels at Rockdale, and continue south.
The stage one tunnels will emerge through sports fields on to President Avenue, Kogarah, but will not impact the Brighton Memorial Playing Fields, as previously indicated.
Community facilities in Rockdale Bicentennial Park, including the skate park, play area and barbeque equipment, will need to be relocated.
The southern ventilation outlet will be located in the industrial zone on West Botany Street, Rockdale, while the northern “stack” will be integrated with the ventilation facilities for the New M5 Motorway located near the M5 East and Marsh Street intersection.
A project overview was released with the announcement on Tuesday by Premier Gladys Berejiklian that stage one was fully funded and was expected to cost between $2.2 and $2.6 billion.
Illustrations confirm the route will swing around from the WestConnex at Arncliffe under Banksia and Rockdale to President Avenue, Kogarah.
A connecting tunnel stub for stage two to Sans Souci or Taren Point is located around Bay Street, Rockdale.
The document said the relocation of community facilities would be done in consultation with Bayside Council, local sporting clubs and other interested stakeholders through the Stakeholder Liaison Group.
“Recreational facilities will be relocated before the start of major construction work in consultation with Bayside Council,” the document said.
“There are no plans to impact either the Ilinden Sports Centre playing field or Brighton Memorial Playing Fields.
“The ‘cut and cover’ section of the tunnel will need to pass around five metres underneath the waterway in Rockdale Bicentennial Park.
“To construct this it will be necessary to temporarily divert the course of the waterway.
“This will also require the removal of the existing pedestrian bridge across the waterway.
“The temporary diversion shown below, will be designed to maintain water levels in the existing waterway, as well as minimise the risk of potential flood events.
“The temporary diversion will be closely monitored to ensure there is no impact on existing aquatic life.
“Once construction work has been completed the waterway will be restored and the pedestrian bridge reinstated.”
The project overview said the tunnels would end around 25 metres under West Botany Street.
“From West Botany Street the tunnels gradually rise until they surface in the existing F6 reserved corridor and form a new surface road connection with President Avenue at Kogarah.
“As the tunnels pass under Rockdale Bicentennial Park they will rise from 25 metres deep to 10 metres under the surface.
This section will be constructed as a ‘cut and cover’ structure, meaning that a deep trench will be dug for the tunnels, which will be completely covered when construction is finished.
“The land will be returned to parkland and open space for community use.”
The document said all traffic would either enter or exit at the President Avenue intersection.
“The speed limit entering and exiting the tunnel at President Avenue will be 60 kilometres/hour, consistent with the speed limit on the surrounding road network.
“The intersection will consist of dual two lane ramps to the north.
“The southbound tunnel off-ramp will widen to four lanes at the new intersection.
“President Avenue, between West Botany Street and O’Connell Street, will be widened to provide three lanes in each direction as well as turning lanes.
“President Avenue will be raised by up to three metres between O’Connell Street and Civic Avenue to provide flood immunity to the tunnel exit and entry.
“Construction work will be staged to allow for the relocation of utilities and to maintain the existing lanes and traffic movements on President Avenue.
“A cul-de-sac at O’Neill Street is required due to the proximity of the new President Avenue intersection.
“Access to the eastern side of O’Neill Street will be via Crawford Road.
“There may be changes to other local intersections to allow for the successful integration of the new intersection on President Avenue.
“Potential changes to local roads will be discussed with Bayside Council and the local community.”