NSW flood: Sydney residents west and northwest evacuated after Warragamba dam overflows | Floods off the east coast of Australia 2022

New South Wales authorities have warned communities at risk of major flooding in the Sydney region to evacuate or prepare to evacuate as the Hawkesbury, Nepean and Georges rivers continue to rise.

The Warragamba Dam, Sydney’s main reservoir, was spilling at a rate of more than 70 gigalitres per day on Wednesday after torrential rainfall over its catchment exceeded previous forecasts, according to a NSW government official.

The spill, which started around 3am, was expected to peak on Thursday. The previous expectation for a higher spill interval at 350 GL per day has now increased to match or exceed the 440 GL / day rate experienced during the March 2021 floods. This event caused extensive damage in areas north and west of Sydney.

Extreme levels of flood danger were announced in southwestern Sydney, exceeding March 2021 levels with strong flood warnings. It is raining, with some areas hit harder than others and more rain on the road. Take the warnings and forecasts seriously, the NSW Bureau of Meteorology said before 9 p.m.

This is our worst fear, NSW Deputy Prime Minister Paul Toole said earlier Wednesday evening. It will get worse before it improves.

In a worst-case scenario, the Warragambas spill rate could reach 600 GL / day, Toole told a news conference. A possible evacuation could involve several hundred thousand people, said NSW State Emergency Service commissioner Carlene York.

The Port of Sydney holds approximately 500 GL. More flood water is also flowing into the Hawkesbury-Nepean region from other tributaries entering the floodplain below the dam.

There were also concerns that Redbank Dam could fail, prompting the SES to direct people in parts of North Richmond, northwest Sydney, to evacuate.

We just issued an evacuation order for the area in North Richmond downstream of the Redbank Dam because it might fail, York said. I want all those residents to make sure they are evacuated from that area.

Residents they were told to evacuate in some areas of Agnes Banks, Bligh Park, Camden, Cattai, Chipping Norton, Georges Hall, Lansvale, Leets Vale, Milperra, Moorebank, Sackville, Warwick Farm and other suburbs.

Authorities also told thousands of other residents affected by the 2021 Sydney floods that they were on high alert.

NSW Health told people isolated because of Covid that they should evacuate their home if threatened by rising flood waters.

If you are told to evacuate, you must evacuate, said NSW Acting Chief of Health Dr Marianne Gale. An urgent evacuation is a valid reason to leave your home.

The Bureau of Meteorology changed its forecast of when the heaviest rainfall in Sydney could come down, forecasting 120 mm to 150 mm on Thursday, from 50 to 70 mm. As of 9 a.m. Wednesday morning, the city had only collected about 10 mm, though the inland areas were much wetter, with about 84 mm by 5pm in Richmond.

The Bureau has also issued a flood warning for the Nepean and Hawkesbury Rivers.

Significant rises in river levels have been observed along the Nepean River, where major flooding is possible as of Wednesday evening, BoM said.

Along the Hawkesbury and Lower Nepean rivers, heavy flooding is also possible from Wednesday night through Thursday in Penrith, North Richmond, Windsor and downstream based on forecast rainfall.

We will become massive, like torrential rainfall, said Stephanie Heard, a spokeswoman for NSW SES.

We want the community to start preparing for the potential for evacuation. We really need to make sure the community listens to and follows our advice. Basically, it’s really a pretty dangerous weather system they were seeing.

There were already 18 flood rescues in the Sydney region by Wednesday afternoon. Total rainfall could reach 150 mm to 200 mm over the Hawkesbury region, Heard said.

While Sydney itself had been spared most of the dense rain from the developing east coast, inland areas, including the Warragamba watershed, had received heavy rainfall.

Ben Domensino, an old weather meteorologist, said the rain gauge at Warragamba had collected almost 100 mm from 9 a.m. to 3 p.m. By comparison, the Sydney Observatory Hill near the CBD was only about 30 mm in 30 hours until 3pm on Wednesday.

The system has continued to surprise in terms of rainfall rate, Domensino said, noting its evolution from a so-called rain bomb over southeast Queensland and north NSW into a low-pressure system near NSW’s central shore.

This system is currently causing much heavier rainfall in the range than near the coast. There is likely to be some dense rain near the coast, especially as the low pressure system comes on overnight until Thursday morning.

People who may need to be evacuated should prepare an emergency package and collect pets, which evacuation centers will be able to house, SESs Heard said. The kit should include key valuables, but also Medicare and other IDs. More details can be found here.

Not surprising given the spill from Warragamba, the dam is 100% full., said WaterNSW. The entire dam network has shrunk to 99.2% and it is likely that all of them will overflow by the end of this rain event.

In addition to warnings of flooding and heavy rainfall, there are also strong winds and dangerous forecasts for surfing, the latter up and down the NSW coasttha BoM.