Heavy flooding has washed away large sections of a road crossing near Araluen, east of Canberra, leaving multiple residents trapped.
Large rainfall on Sunday led to the Neringla Road crossing over the Araluen Creek collapsing on Sunday.
Residents in areas for 12 kilometres south of the creek crossing have been trapped as a result of the bridge collapse with the road being the only way in or out.
Queanbeyan Palerang Regional Council workers have been on the scene since Sunday, attempting to restore road access for trapped residents.
Since 9am on Saturday, more than 115 millimetres have fallen in nearby Braidwood, according to the Bureau of Meteorology.
Council mayor Tim Overall said the large rainfalls have caused the abutment of the bridge in Araluen to collapse.
"We've got staff heading out there on Monday to do work and restore access temporarily until we can do more substantial work," Mr Overall said.
"It's an ever-changing situation. There's a number of areas where the water is too high so we're advising people not to cross flooded crossings because you just don't know what's underneath that water."
Multiple other river crossings have been cut off in the Queanbeyan-Palerang area as a result of the flooding.
Among them are the Reschs Creek crossing off Hoskinstown Road, along with the Briars Sharrow crossing, also off Hoskinstown Road.
Other roads affected include Charleys Forest Road, Bombay Road, Mayfield Road and parts of Oaks Estate in the ACT.
A spokesman for Queanbeyan Palerang regional Council said it was not known how many residents had been trapped by the collapsed bridge, but it would be several days before full access could be restored.
Work would also be conducted around other trapped roads in the council area.
"Council staff have been sent out and checking when roads will be safe to cross and when road closures can be taken away," the spokesman said.
"It will be different because all the rivers feed into different areas.
"Staff have also gone out to Captains Flat Road to clear trees and check the road for debris."
The heavy rain also led to many trees coming down along Hoskinstown Road and Captains Flat Road.
The bureau has predicted a 60 per cent chance of showers in areas to the east of Braidwood.