The force of the floodwaters smashed shop windows and knocked out the back wall of a local supermarket in the central-western town of Molong, a statement from NSW Fire and Rescue said on Monday.
Fire and Rescue crews in Molong rushed to action around midnight, helping the State Emergency Service and other agencies door-knocking threatened homes and evacuating people.
A makeshift landing strip was established, with flashing lights on the oval of the Molong Central School, to guide an ADF helicopter to help rescue people trapped in floodwater and conduct medical retrievals.
Fire crews also rescued two people and their dog from knee-deep water inside a house and another couple from the top floor of a motel.
The firefighters and a police officer waded through chest-high water to reach another woman stranded in her inundated home.
At least two large shipping containers were carried through the centre of the historic town by floodwaters and are blocking the Mitchell Highway.
Roadblocks have been established to prevent heavy vehicles passing through the floodwaters and causing further damage and an evacuation centre has been opened at the RSL club.
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.
Firefighters say floodwaters are receding and they have begun clearing a large amount of mud and debris from Molong's streets.
The SES responded to 33 flood rescues and 462 requests for help in the 24 hours to Monday morning.
It 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 across 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 six hours overnight.
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 and cause major flooding at Nanami, Forbes and Cottons Weir.
The Bureau of Meteorology says the Lachlan River at Cowra could reach 11.3m 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 the SES helped rescue people from six vehicles in the central-western town of Woodstock after a bridge was washed away.
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.
