A young family were tossed into floodwaters on the Hawkesbury River when an SES boat capsized during a rescue today.
The attempted evacuation was taking place in Colo today with a couple and their two children pulled soaking wet from the water.
Eventually the family made it across the river and delivered to a staging point at the Sackville Ferry Crossing.
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The rescue was part of a huge operation to evacuate hundreds of residents stranded along the Colo River in the NSW Hawkesbury region.
The State Emergency Service (SES) is warning people in Upper Colo, Lower Colo, Colo Central and Wheeny Creek after the river peaked at 11 metres this morning.
However, the threat is far from over as roads are still cut off by floodwaters.
Trucks carrying supplies and essentials such as food and medicine are on their way to nearby Windsor now conditions have eased slightly.
The SES evacuation order was initially issued about 8am, and an update at 4pm.
Residents are being urged to take only essential items such as warm clothes, medicines and insurance documents.
People who do not follow the evacuation order risked being trapped without power, food and water, the SES said.
It comes as the state faces multiple weather fronts which represent a "catastrophic" threat.
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New South Wales Premier Gladys Berejiklian said the Upper Colo River Valley and the Hawkesbury are of particular concern.
"About 18,000 people have been evacuated," she said.
"An additional 15,000 people may need to be evacuated…The fact that 15,000 people may need to be evacuated in the next 24-48 hours is a huge concern."
NSW SES Commissioner Carlene York said 200 homes are at risk in the Colo River area.
NSW towns on the Mid North Coast, the Upper Colo River Valley and western NSW could be cut off, as rain continues to fall and flood waters rise.
"Access is very difficult at those remote areas so we will have rescue boats and helicopters going in to assist those people," Ms York said.
Ms York said it may not be possible for the SES to rescue animals.
She said people should move animals to higher ground.
Ms Berejiklian said clean-up and recovery operations will "take weeks".
"Many river systems are still taking major flows … so there could be flooding in communities we have not anticipated," she said.
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In the last 24 hours, there have been 1300 requests for assistance across the state.
NSW Emergency Services Minister David Elliot said "statistically" NSW was "crawling towards the inevitable fatality."
There is already major flooding at North Richmond and Windsor and it may barely recede for most of the week based on rain expected in coming days, the Bureau of Meteorology (BOM) says.
Forecasters are expecting 50mm to 100mm of rain to fall in the next 12 to 24 hours across many parts of NSW.
The BOM is warning of flash flooding bringing a serious risk to the whole northern and central coastal districts of NSW today, particularly in the Northern Rivers , Mid North Coast, Lower Hunter, Blue Mountains, and Sydney Metro regions.
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It warns the extreme weather will be life threatening in some areas.
The heavy rain along the central coastal districts including Sydney Metro, Lower Hunter and Illawarra is expected to ease later today as the rain band contracts to the north and south.
The BoM has also issued warnings of damaging winds averaging 60km/h to 70 km/h, with peak gusts in excess of 90 km/h possible along the coastal fringe south of Seal Rocks from late this morning.
The SES – which has deployed about 2000 people – and other emergency services have been extremely busy over the past couple of days.
It has responded to 9000 jobs and carried out 870 flood rescues.
The BoM warned 10 million Australians were under a weather warning as two major systems collided, leaving Western Australia the only mainland state not affected.
"It may have been going for days but unfortunately this situation is far from over," the BoM said.
Warnings for heavy rain, damaging winds and heavy surf cover an area similar in size to Alaska.
Meanwhile, the Australian Defence Force will send two search and rescue helicopters to flooded areas today after NSW requested backup.
"The search and rescue choppers will be able to work through night and day and supporting personnel will be made available to make this happen," David Littleproud, the Minister for Emergency Management, said.
