A pregnant woman who was trapped by rising floodwaters when her waters broke has safely given birth after a dramatic rescue.

First-time mother Mamata Pun Rama delivered a healthy boy after emergency workers ferried her through the NSW town of Forbes.

Rising rivers have cut the town in two and created “islands” and about 500 properties were subject to evacuation orders.

Baby Imaan was born in Forbes hospital “blissfully unaware of the incredible circumstances surrounding his delivery,” a hospital spokesperson told media.

SES volunteer Ryan Jones, who performed the rescue, said the woman was cut off by floodwaters in north Forbes and she needed help crossing the inundated roads to get to hospital with her midwife.

“The water was too deep and dangerous for private vehicles, so the only way for us to access this patient was via use of our high-clearance vehicles,” he said.

Another person was rescued from their car after being trapped by rising waters near the centre of town.

Chitra and Mamata Pun Rama with baby Imaan in Forbes Hospital. Photo: Western New South Wales Local Health District.

The Lachlan River in the NSW central west town should start to recede on Sunday, but authorities have warned downstream communities are still at risk.

Several communities in NSW remain on high flood alert as authorities warn of floodwaters moving downstream.

The Lachlan River was sitting steady at 10.66 metres on Saturday evening — just below the highest level in 70 years — with waters expected to start receding on Sunday.

However, SES Forbes unit commander Robert “Rocky” Walshaw warned it would be a slow process.

As for when clean-up efforts could start, he said: “It be could be virtually another week yet. It comes up very slow, and it will go down very slow. It takes a long time to drain out.”

The water had come into many homes in lower-lying areas, and also reached business areas, Mr Walshaw said.

“I’ve seen shots of it from the air, from the (helicopters), and it’s just water everywhere,” he told AAP on Saturday.

“At 3.30 this morning, we started getting calls from people who needed to be evacuated because they didn’t expect the water to come up to them.

“We had about six or so in the early hours of the morning.”

The town of Forbes could be dealing with floodwaters for a week. Photo: AAP

In the 24 hours to 4pm Saturday, the NSW SES had fielded nearly 280 requests for assistance statewide, and conducted 27 flood rescues.

In the previous week, they’d received more than 2600 calls for help and responded to more than 130 flood rescues.

A number of major flood warnings remained in place on Saturday evening in NSW including for the Lachlan, Namoi, Bogan, Macquarie, Murrumbidgee, Murray, Edward, Culgoa, Birrie, Bokhara and Narran rivers.

Moderate flooding was occurring at Wagga Wagga on Saturday, with major flooding possible at Narrandera on Tuesday.

Renewed rises were likely at Carrathool and further downstream at Hay, with rises at the latter likely from mid-November.

Emergency Services Minister Steph Cooke said on Saturday the floodwaters affecting Wagga Wagga and Forbes were moving downstream and risks of major floods remained for several communities.

“While we are experiencing a reprieve in the weather and, in fact, it’s lovely to see some blue skies, the risk has not abated in relation to the amount of water in our river systems, passing through our communities and impacting on our lives,” she said.

Victoria

Across the border in Victoria, more than 40 flood alerts remained on Saturday evening, with authorities warning those at Kenley on the Murray River in the rural city of Swan Hill to evacuate immediately.

Water levels at Mildura are expected to continue rising throughout November before a possible high in December.

Along the Murray River at Echuca and Moama, major flooding was expected to continue into next week although water levels were falling.

-with AAP