Emergency services have warned that Oaks Estate, Pialligo and the Lower Molonglo areas of the territory could be subject to ‘‘significant flooding’’ if intense rainfall continues tonight.
Residents in those areas are being urged to be wary the threat of flooding and the Emergency Services Agency is planning to use the telephone alert system, which failed during last year’s toxic chemical fire in Mitchell, to advise if evacuation is necessary.
Authorities are also urging residents to monitor local media and the ESA’s website, Twitter account, and Facebook page for updates.
The rest of the territory is likely to be hit by flash flooding, with rising waters in local creeks, and flooding near drains, across roads and footpaths.
The rain is also expected to cause significant roof damage, and Canberrans are being warned to stay away from storm water drains or large bodies of water.
Heavy rains are set to intensify from late this afternoon, as meteorologists issue severe weather warnings and forecast major dumps over the ACT and surrounding regions tonight and tomorrow.
A severe weather warning was issued by the Bureau of Meteorology for the ACT, Queanbeyan and areas to the north this morning, and a flood watch has been issued for the Queanbeyan Molonglo River.
Evacuation warnings are in place for Cooma, Goulburn and residents have been evacuated from Tumut.
The bureau has predicted a 70 per cent chance of moderate to major flooding from today in parts of Queanbeyan and the chance of major flooding in Cooma.
Meteorologist Sean Carson said Canberra would start to see intensifying rain throughout the night.
‘‘That will increase through tonight and it looks like we’ll probably see rain continuing all night and for most of tomorrow, with heavy falls likely through that period,’’ he said.
‘‘It will just gradually build, as for the heaviest falls, it will probably in the middle of the night and tomorrow.’’
The rain has caused a raft of closures to roads, low level crossings, and park areas, while drivers have been warned to take care on the Kings Highway, which has been made dangerous because of the wet weather.
Mr Carson said it was difficult to predict whether Queanbeyan would see a repeat of the floods in 2010, when the Queanbeyan River burst its banks and inundated homes and businesses.
But he said a second downpour was likely to hit the region from Friday night through to Saturday.
‘‘The soil is saturated, there’s a little bit of run off there, the next falls will start to make a little bit of a difference depending on how intense they are,’’ he said.
The heavy rains have threatened construction works at the Cotter Dam enlargement project, as water spills over the old Cotter Dam.
ACTEW have begun moving equipment and gear, with fears that intense rainfall could see water spill over the new Cotter Dam, which is still under construction.
Landholders and graziers in low lying areas are also being urged to move livestock to higher grounds as a precaution against possible floods.
The ACT Government has contacted landholders at the greatest risk.
ACT Fire and Rescue and State Emergency Service have responded to 63 calls for help since the rain began yesterday afternoon, with most calls coming from Canberra’s south. Parents and guardians are being warned to ensure children stay clear of swelling floodways.
NSW State Emergency Service Queanbeyan spokesman Mitchell Clout said the unit responded to 10 calls for help yesterday. Most of the calls were from people wanting sandbags around their homes.
‘‘’We’re planning for the worst and hoping for the best,’’ Mr Clout said.
‘‘In the planning stages throughout today we have involved NSW Police and the ACT Emergency Services Agency.’’
The bureau’s NSW regional director Barry Hanstrum said, ‘‘The heaviest falls are most likely in a band running between Broken Hill to the south and central coast, including Ivanhoe, Forbes, Young, Cowra, Canberra, Goulburn, Wollongong and Sydney,
‘‘Some locations could receive falls in excess of 300mm over the next several days. This event is perhaps the most significant rainfall event that some of these areas have seen in decades and records may be broken.’’
Meanwhile, Canberra put itself in the record books yesterday, recording the coldest summer in 16 years, the Weather Channel said.
Its senior meteorologist Tom Saunders said, ‘‘La Nina conditions caused below-average temperatures this summer. The average temperature for the city was 1.1 degree below normal at just 18.7 degrees - two degrees colder than our 2011 summer and more than three degrees colder than our 2010 summer.’’
Bureau of Meteorology climatologist Acacia Pepler said Canberra has also had the fewest days above 30 degrees since the summer of 1992.
It also has not had any days above 35 degrees this summer. That compares to an average of five days above 35 degrees, Ms Pepler said. The last time there were no days above 35 degrees in summer was in 2002.
La Nina’s tend to bring enhanced rainfall and cooler conditions during the summer months, she said.
At this evening, 238mm of rain had fallen on the capital since December 1, well above the historical average of 168.7mm. Last summer 375.2mm was recorded. The summer rainfall record was gazetted in 1948 when 476.9mm of rain fell.
Residents who require assistance can call the ACTSES on 132 500.