A flood watch has also been issued for the Orara and Bellinger Rivers in NSW.
The Bureau of Meteorology said some parts of eastern and northern NSW got more than 200mm of rain in the 24 hours to 9am Saturday including Clothiers Creek (250mm), Tumbulgum (243mm) and Bilambil Heights (212mm).
Residents in Lismore, Ballina, Casino, Kyogle, Yamba and Maclean were warned to expect more heavy rainfall and flash flooding as storms passed over the region on Saturday morning.
“Stay vigilant and monitor conditions. Note that the landscape may have changed following bushfires,” the Bureau of Meteorology said.
“Run-off from rainfall in fire affected areas may behave differently and be more rapid. It may also contain debris such as ash, soil, trees and rocks.”
Torrential rain on Friday saw a creek in Bingara fill and flow with water for the first time in five years, according to the ABC.
Creek coming up at home. Timing was spot on
“Great to see. It brought a bit of a spark to town,” Bingara farmer Robert Kilmore told the broadcaster.
“Everyone in town was driving around to look at it — amazing what rain can do that’s for sure.”
Animals at the Australian Reptile Park on the NSW Central Coast also had to be relocated amid flash flooding.
Footage from the park showed director Tim Faulkner carrying two drenched koalas over a flooded bridge while keepers monitored the alligators in a rising lagoon.
This morning we made the tough decision to close the park for the day due to incredibly heavy (much needed!) rainfall...
“This is incredible!” Mr Faulkner later said in a statement.
“We haven’t seen flooding like this at the park for over 15 years! We’ve even had keepers stationed at our Alligator Lagoon to monitor the water levels, which were rising beyond the fence line.”
Rain is expected to fall across most of New South Wales, barring the state’s west and southwest, across the weekend, with the potential for “supercell” storms on Monday.
Rain and storms have provided useful falls over much of east #NSW in the past few days. Further rain will fall in the east of the state, especially the north east until Sunday. On Monday falls will shift to be heaviest in the south east. NSW forecast: https://t.co/YYPYaRT8Sc pic.twitter.com/6psr0tZPi8
Meanwhile, parts of Victoria have been warned to expect very poor air quality over the next few days.
Easterly winds are forecast to bring smoke haze from fire-ravaged areas to central parts of the state on Saturday, according to Environment Protection Authority Victoria.
A low-pressure system could also mean heavier falls across the state on Sunday and Monday, but it is not yet clear whether that rain will reach bushfire regions.
“Certainly, at this stage, there is the potential that we could see more rainfall across those fire-affected areas,” BOM senior meteorologist Diana Eadie said.
“But it is highly dependent on exactly where that low (pressure system) is, and we will be monitoring that very carefully over the coming days.”
– With AAP