In the 24 hours to Monday morning, the NSW State Emergency Service responded to 33 flood rescues and 462 requests for help.
The SES said a rescue was under way for a man trapped in his car in the central-western town of Alectown who called for help just before 4am on Monday.
Police and Rural Fire Service personnel have spotted the vehicle and a helicopter has been deployed to help rescue the man.
Storms hit the central west on Sunday and overnight prompting three new evacuation orders, including for people in low-lying areas of Eugowra, where flash-flooding is occurring as river levels continue to rise.
People in low-lying parts of the central-western town of Canowindra have also been urged to evacuate immediately because of high river levels and dangerous flash flooding.
An evacuation centre has opened at the local public school after the town recorded 99mm of rain in just six hours overnight.
The historic town of Molong, in the Central Tablelands near Orange, is completely isolated by floodwaters, with flash flooding making it too dangerous to evacuate.
The SES is warning people in Molong's low-lying areas to move to higher ground.
An evacuation centre has been opened at the RSL club, while an ADF helicopter has been sent to help rescue people trapped in floodwater and help with medical retrievals.
Cabonne mayor Kevin Beatty, whose territory includes Molong, says the picturesque town is devastated with shops in the main street inundated and people evacuated from homes and motels.
The Mitchell Highway is underwater and floating refuse is everywhere, including a large unidentified object that's blocking the major thoroughfare.
"I don't what it is ... there's either a big caravan or big shipping container sitting right on the highway on the bend in the middle of town," he told Sydney radio 2GB on Monday.
Condobolin copped 80mm of rain overnight, causing the Lachlan River to rise to 7.3 metres, with expectations it could exceed the June 1952 record, causing major flooding at Nanami, Forbes and Cottons Weir.
The Bureau of Meteorology says the Lachlan River at Cowra could reach around 11.3 metres on Monday, with moderate flooding and further rises possible, as more rain is forecast.
In the southern border town of Albury, the SES was called to rescue two children playing in a stormwater drain on Sunday, while at the central-western town of Woodstock the SES helped rescue people from six vehicles after a bridge was washed away.
The bureau has cancelled a severe thunderstorm warning for the mid-north coast, the Hunter, the Central Tablelands, the northwest slopes and plains, the central-west slopes and plains, upper western and Northern Tablelands districts.
The bureau says the immediate threat of severe thunderstorms has passed but the situation will be monitored and further warnings issued if necessary.
SES Assistant Commissioner Nicole Hogan said flooding would continue to affect multiple communities in inland NSW this week.
The SES is delivering food, medicine and animal feed to 1000 residents cut off by floodwaters since severe weather began in mid-September and has carried out 500 flood rescues.
SES Commissioner Carlene York said the volunteer workforce was fatigued and personnel have been requested from other states.
Flooding continues across western and southern NSW, in towns including Collarenebri, Walgett, Bourke, Condobolin, Hay and Albury.
