Residents were told to evacuate Lismore after the State Emergency Service confirmed that a levee had breached its banks, inundating the CBD with floodwaters.

Flash flooding was reported in numerous towns, including Tygalgah, Burringbar and Tumbulgum.

The Bureau of Meteorology warned the Wilsons River at Lismore was rising and predicated to peak on Friday morning.

The Sydney Morning Herald reported thousands were evacuating the town following a severe weather front brought by ex-tropical cyclone Debbie, and emergency crews were struggling to access flood-affected areas.