An evacuation order has been issued for residents of Forbes in central-western New South Wales to leave their homes by 5pm on Saturday.

Forbes is bracing for major flooding, with the Lachlan River expected to peak at 10.65 metres about midday on Sunday.

Flood warnings remain in place across the state’s central west.

The evacuation order covers streets in the city’s south, south-west, north, east and CBD.

Residents have been advised not to delay their evacuation, with roads expected to be congested or closed.

The State Emergency Service (SES) said remaining in flooded areas could place lives at risk.

Evacuation orders are already in place for nearby Ungarrie and the Wagga Beach Caravan park.

Residents have been told they could be away from their homes for some time, and should pack for at least five days.

SES spokeswoman Becky Gollings urged residents to continue making preparations to leave their homes.

The SES has carried out three flood rescues overnight, and 90 flood rescues across the past three-and-a-half weeks since flooding began.

Best thing is to leave early, SES says

SES acting commissioner Mark Morrow said some people had left Forbes already.

An evacuation centre has been set up, but residents were encouraged to stay with friends or relatives if possible.

Mr Morrow said the best thing was to leave early.

Residents advised to leave early because roads may be closed. Photo: ABC

“If they do stay, there could be a loss of structure, they may lose sewerage pumps in town,” he said.

“They could lose power. There probably won’t be telephones.”

Mr Morrow said there were a lot of factors during flooding that could not be controlled, including dead livestock contaminating floodwaters, and chemicals that may leak into the water from farms.

“There is no good reason to stay if you are going to be inundated with water,” he said.

There are about 1,000 people affected by the evacuation order.

Forbes businesses fear stock losses

Forbes business owners and staff are working hard to prepare ahead of the flood peak.

Kim Lowe and her staff have been busy moving stock. Photo: ABC.

Susan Chaw was hoping to open her new cafe in mid-October, but instead she has been helping with flood preparations.

“I think [the flooding is] going to push the progress back a month because we’ve had to move all the new equipment up from the ground level,” she said.

Interior design business owner Kim Lowe has been working with staff to move stock off the ground and take store fittings out of the building.

“For the last four weeks we’ve had trouble getting staff here because roads have been cut,” she said.

“It actually looks like we’re going to lose quite a lot of business and also loss of stock if it gets really bad.”