Floodwaters hit Forbes as Lachlan River expected to peak overnight

Forbes is being inundated by floodwaters as the Lachlan River rises to its expected peak of 10.8 metres.

Flood warnings are in place across 25 areas in Central West New South Wales as locals in Eugowra, and surrounding towns near Orange, begin a mammoth clean-up mission.

The entire township of Forbes has evacuated as flooding divides the town into three: the north, CBD and south.

Residents have been ordered to stay in the area they are in right now and remain there for several days or until floodwaters recede.

The Bureau of Meteorology (BoM) is expecting the Lachlan River to peak overnight and into tomorrow morning, which is a similar reading to the 1952 flood for the second time in as many weeks.

NSW residents can stay up to date with the latest emergency warnings at the SES website.

If waters reach the record height, 500 to 600 homes are expected to be flooded.

Waters at Canowindra were at 14.3 metres, a metre higher than the flooding last November.

Cowra also recorded its highest daily rainfall total in 118 years on the weekend, with 121mm.

Forbes mayor Phyllis Miller said locals were fully prepared.

"The houses that were damaged in the last flood two weeks ago, fortunately not too many people had moved back in," Miller told 9News.

"It's just a waiting game… the water comes down from Wyangala and we just sit and wait to be washed off the map.

"I have spoken to a few personally and it's tough on them… they had the big driers in (their homes) and they were looking forward to being able to move back in but of course that's not going to happen again."

Earlier NSW Emergency Minister Steph Cooke said in the past 24 hours, there had been more than 900 calls for help to the SES, and 222 flood rescues.

"We now have 70 local government areas that are the subject of a natural disaster declaration as a result of this event, which is now in its 63rd day," Cooke said.

NSW Premier Dominic Perrottet warned of a difficult period over the next couple of days for Eugowra and Forbes.

"In Eugowra and Forbes, there is a continued focus at the moment on the response, on rescues, on keeping people safe," Perrottet said.

"Clean-up and recovery is now in the early stages in Molong, in Canowindra, and the ADF are providing assistance there."

An extra 100 defence personnel are on the ground helping with the flood response.

Perrottet says his government is committed to raising the Wyangala Dam, which is currently spilling 230 gigalitres a day into the Lachlan River.

"You've got a situation right now where that catchment is spilling," he said.

"There's a lot of water coming out of it and we need to make sure that in years to come, when we're facing the same situation, that we've made the decision and made the investment to protect those communities and that's what we're going to do."

SES Commissioner Carlene York said the organisation would look at its resources to make sure it could meet future challenges, as international help arrives.

"The NSW SES are leading what would be the biggest operation in relation to flood response across NSW in its history," she said.

New Zealand fire and emergency services have sent 12 people to help in the crisis.

Earlier, locals in Cudal told 9News the water in a creek behind their homes rose so quickly it caught them off guard.

"If I had have stayed in bed… I would have been a bit muddy," resident Nick said.

Helicopters and boats were used to carry out over 150 rescues in the inundated town of Eugowra, where people were forced to make for their roofs as floodwaters rose.

Those residents have started a register system to ensure everyone has made it safely to a friend's place or to an evacuation shelter.

The LifeFlight helicopter has rescued 18 people and 14 pets from floodwaters in the NSW Central West.

Video shows a "wall of water" bringing devastation to New South Wales towns, which comes as the Wyangala Dam spilled record amounts of water, after 100mm rain fell in just a few hours.

Floods have ripped up the road and destroyed a bridge into the town of Canowindra, while the Wyangala Dam is spilling 80,000 gigalitres a day into the Lachlan River.

The first rescue occurred at Ophir Reserve Campground near Orange after floodwaters quickly submerged the area, surprising campers.

Three people and a dog were rescued from the site.

"The campers told the crew it wasn't raining when they went to bed last night, but they awoke early this morning to water rising halfway up caravans," LifeFlight said in a statement.

"The crew provided care to keep them warm as they were suffering hyperthermia-like symptoms."

The group was then transferred to an ambulance at Orange Airport.

The LifeFlight helicopter has rescued 18 people and 14 pets from floodwaters in the NSW Central West.

The helicopter continued on its rescue mission to Eugowra where two neighbours were trapped by surrounding fast-flowing floodwaters.

"The LifeFlight paramedic, who is also a qualified rescue crew officer, was first winched down to a woman waiting in her house and brought her up to safety before rescuing the neighbour from the back of a ute," LifeFlight said.

Residents in and around Eugowra remained under directions to move to higher ground with those in other small towns in the area such as Gooloogong and Canowindra told to evacuate.

Further upstream, the helicopter found a woman whose home had been destroyed after floodwaters blew out the windows due to the shear force of the torrents.

"She had made it out onto dry ground so the crew was able to land the Land Rover LifeFlight Special Mission helicopter in a nearby paddock to collect her," LifeFlight said.

The LifeFlight helicopter has rescued 18 people and 14 pets from floodwaters in the NSW Central West.