Australia: Further flooding likely across eastern regions through at least Dec. 27 /update 20

Event

Further flooding is likely across the Australian Capital Territory, New South Wales, and southern and eastern Queensland through at least Dec. 27. As of Dec. 20, the Australian Bureau of Meteorology (BoM) has issued the following flood warnings:

• Major flood warning: Balonne River in Queensland.

• Minor to major flood warning: Barwon and Darling rivers in New South Wales.

• Moderate to major flood warning: Culgoa, Birrie, Bokhara, and Narran rivers in New South Wales.

• Moderate flood warning: Weir River in Queensland and New South Wales; Bogan River in New South Wales.

• Minor to moderate flood warning: Namoi River in New South Wales.

• Minor flood warning: Lachlan, Murrumbidgee, Paroo, Snowy, and Warrego rivers in New South Wales.

Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.

Major flooding is forecast or currently occurring along the following rivers and creeks:

• Balonne River: major flooding likely to continue downstream of Beardmore Dam as well as along the Balonne River Minor at Dirranbandi through at least Dec. 23, while major flooding is likely along Bokhara River at Hebel Dec. 22.

• Barwon River: at Mungindi and Mogil Mogil through Dec. 27 with major flooding likely at Walgett Dec. 22.

• Culgoa River: major flooding likely at Brenda by the end of December and at Weilmoringle the first week of January due to floodwaters from the Condamine-Balonne River system in Queensland.

• Darling River: major flooding likely downstream of Bourke to Tilpa; at Louth the second week of January and at Tilpa the third week of January.

• Narran River: major flooding possible at Angledool Dec. 24-25 due to floodwaters from the Condamine-Balonne River system in Queensland.

Reports indicate at least three deaths in Queensland over the past weeks due to flooding, including one fatality in Yalangur, west of Toowoomba, Dec. 1, one fatality in west Brisbane Dec. 8, and another death in Aspley, north of Brisbane, late Dec. 9. Flooding also resulted in another fatality in Tuross in the Snowy Monaro Region of New South Wales early Dec. 10.

Further heavy rainfall could trigger additional flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed or a lack of stormwater drainage systems. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides cannot be discounted in hilly or mountainous areas, especially where the soil has become saturated by heavy rainfall; surface runoff along bushfire burn scars could also result in dangerous mudslides.

Authorities could issue mandatory evacuation orders for flood-prone communities over the coming days. Disruptions to electricity and telecommunications services are possible where significant flooding or landslides impact utility networks.

Transport and Utilities
Flooding could cause transport and utility disruptions across eastern Australia. Flooding and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters.

Severe weather could also trigger flight delays and cancellations at regional airports. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see heavy rainfall and potential track inundation. Localized business disruptions may occur in low-lying areas; some businesses might not operate at full capacity because of flood damage to facilities, possible evacuations, and some employees' inability to reach work sites.

Advice

Monitor local media for weather updates and related advisories. Obey all evacuation orders. Confirm transport reservations and business appointments prior to travel. Make allowances for localized travel delays, as well as potential supply chain disruptions, where flooding has been forecast. Do not drive on or through flooded roads. Charge battery-powered devices in case prolonged electricity outages occur.

Resources

Australian Bureau of Meteorology (BoM)
NSW State Emergency Service (SES)