SYDNEY - Almost 50,000 people have been isolated by rising floodwaters in the Australian state of New South Wales (NSW).

The NSW State Emergency Service (SES) said on Wednesday afternoon that over 48,800 people and 23,200 dwellings have been cut off by flooding in the state's Mid North Coast region, over 200 km northeast of Sydney.

The Mid North Coast and surrounding regions have experienced four consecutive days of heavy rainfall, causing widespread record-breaking flooding.

The SES has issued 109 flood warnings and ordered evacuations across the affected area and opened evacuation centers.

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In an update shortly after 5 p.m. local time on Wednesday, the SES said that emergency service crews had completed more than 400 flood rescue operations, with helicopters and boats deployed to help people who had become trapped.

The Australian Defense Force (ADF) has been deployed to aid with air evacuations.

SES Chief Superintendent Dallas Burnes told Australian Broadcasting Corporation (ABC) radio that rescue operations would continue into the night but that such operations are "incredibly dangerous."

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The Manning river in the Mid North Coast on Wednesday morning surpassed its 1929 record flood level.

Natural Hazards Research Australia, the national center for disaster risk reduction, said that the record-breaking flooding along the river had an estimated occurrence frequency of once every 500 years on average.

The federal and state governments have activated disaster assistance for residents of communities in 16 local government areas, making them eligible for support funding to cover the costs of emergency accommodation and essential items.

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The Bureau of Meteorology said in a severe weather warning issued shortly after 4:30 p.m. local time that parts of the Mid North Coast and adjacent Northern Tablelands region could receive up to 300 millimeters of rainfall over the next 24 hours.

ABC meteorologist Tom Saunders said that the worst flooding is yet to come for many areas.

The regional airport in Port Macquarie, over 300 km northeast of Sydney, has been closed until further notice and over 200 schools in affected areas have been shut.