Tens of thousands of people have been forced to evacuate across Australia's east coast on Friday (31 March) after fast-flowing waters covered roads and destroyed bridges, as remnants of Cyclone Debbie sweep through the region.

Cyclone Debbie
Aerial view shows three vehicles stranded on a highway that was flooded, near Gunyarra, QueenslandAustralia Defence Force/Reuters

Flood sirens sounded before dawn at Lismore, home to 25,000 people in the Northern Rivers region of the state of New South Wales, when the Wilsons River surged over the town's levee. By daybreak the centre of the town was underwater. Water was at roof level and cars, bins and other debris washed down streets, as residents fled and farmers drove their cattle to higher ground. Stranded residents climbed onto roofs of flooded homes to await rescue, but fast-moving water and high winds hindered emergency crews reaching some people. More than 100,000 homes are reportedly without power.

Authorities have ordered almost 20,000 people to evacuate to higher ground across parts of southern Queensland and neighbouring NSW, where thousands of schools also shut.

Cyclone Debbie
Locals try surfing down the main street in BillinudgelJason O'Brien/Getty Images
Cyclone Debbie
Local residents wade through floodwaters near their homes in the northern New South Wales town of LismoreAAP/Dave Hunt/Reuters
Cyclone Debbie
A man rows his boat through a submerged McDonalds restaurant car park after floodwaters entered the northern New South Wales town of LismoreAAP/Dave Hunt/Reuters
Cyclone Debbie
A woman walks through floodwaters in the northern New South Wales town of LismoreAAP/Dave Hunt/Reuters
Cyclone Debbie
A local resident watches as floodwaters enter the main street of Lismore in northern New South WalesAAP/Dave Hunt/Reuters

Premier of New South Wales Gladys Berejiklian told Reuters that they "still have to try and get 20,000 people back to their homes, that is a big operation. There are seven evacuation places, or places of safety. But, we also know that many people have sought refuge with family and friends and until those people are able to get back to their homes, we want the efforts on safety in the community and we'll assess the situation over the next few days."

Forecaster Nicholas Shera, an official of the Bureau of Meteorology (BOM), said the fast-moving cyclonic air moved upwards in a clockwise direction, drawing water into a cloud formation that is now hitting the eastern coast.

Cyclone Debbie
Residents look at the damage in South MurwillumbahJason O'Brien/Getty Images
Cyclone Debbie
A man looks at the damage caused by floodwaters on a main road in South MurwillumbahJason O'Brien/Getty Images
Cyclone Debbie
A man watches as floodwaters enter the main street of the northern New South Wales town of LismoreAAP/Dave Hunt/Reuters
Cyclone Debbie
A car is submerged by floodwaters in BillinudgelJason O'Brien/Getty Images
Cyclone Debbie
A car stranded in floodwaters in MurwillumbahJason O'Brien/Getty Images
Cyclone Debbie
A car surrounded by floodwaters, after the Logan River near Beaudesert broke its banks, inundating surrounding areas in BrisbaneGlenn Hunt/Getty Images
Cyclone Debbie
The Mount Lindesay Highway is under water after the Logan River broke its banks, flooding surrounding areas in BrisbaneGlenn Hunt/Getty Images
Cyclone Debbie
A motel is inundated by floodwater in South MurwillumbahJason O'Brien/Getty Images
Cyclone Debbie
Two ducks sit on a tree that has been damaged by the floodwaters in BillinudgelJason O'Brien/Getty Images
Cyclone Debbie
A tree, damaged by the strong winds, in the Brisbane Botanical Gardens in BrisbaneGlenn Hunt/Getty Images
Cyclone Debbie
A tree in Herston that was damaged by strong winds and rain in BrisbaneGlenn Hunt/Getty Images