At 11.55am on Monday a triple-0 call was received from two people who were left stranded on the roof of their car after they got caught in the fast-moving waters.

NSW Rural Fire Service (RFS) Chifley/Lithgow operational officer Brett Taylor said river water was rushing across the top of the car's bonnet.

"The emergency call was to a car stuck in the Abercrombie River on Abercrombie Road, south of Oberon," he said.

Mr Taylor said it initially sounded like a full-scale emergency with triple-0 operators considering sending out a rescue helicopter.

"When crews got on scene the [vehicle] occupants had removed themselves and got themselves back to shore," he said.

Earlier on Monday morning the fast-moving water had been rushing at two metres above the level of the road.

"It was a very lucky escape," Mr Taylor said.

With more rain predicted in the region, he urged all motorists not to drive through floodwaters.

There were no reported injuries.