The State Emergency Service warned that North Wagga Wagga and Gumly Gumly will be evacuated before the Murrurmbidgee River rises to an expected peak of 9.6 metres on Monday.

In the central west, Parkes was isolated after 106 millimetres of rain fell over five hours yesterday, while about 1000 residents of Coonamble, another town cut off by floodwaters, were on alert for possible evacuation.

There have been evacuations from the village of Jugiong on the Murrumbidgee and the SES conducted five rescues in Parkes, spokesman Phil Campbell said.

Many farmers in the state's west, with black soil roads which are impassable in the wet, have been isolated. About 140 people have been cut off in the Pilliga scrub.

Rural landholders on the north-west, central west and south-west slopes and plains should stock up immediately on food and fuel and move stock to safe pastures, Mr Campbell said.

The Bureau of Meteorology has predicted further heavy rain next week.

''This is a protracted flood event, likely to last this weekend and into next week,'' Mr Campbell said.