The water is rising and spreading through an already saturated catchment following further rain on the weekend.
Forbes Airport had measured 21.8mm from Friday to Monday afternoon.
The water is expected to reach the moderate flood level of 9.5 metres at the Iron Bridge on Tuesday morning and 5.6m at Cottons Weir on Tuesday afternoon. Major flooding continues at Jemalong.
The Mandagery Creek is expected to peak at 8.2m at Eugowra this afternoon and the Belubula is expected to reach moderate flood levels at Canowindra.
The Henry Lawson Way to Grenfell has been closed again due to flash flooding about 30km out of Forbes.
Yesterday morning the SES had already been called to rescue one motorist from water on the Henry Lawson Way and another driver from water on one of the roads off the New Grenfell Road.
Local SES controller Roc Walshaw said the water was rising again when he returned from a surveying flight over the region yesterday morning.
“The Henry Lawson Way is closed – Grenfell had about three inches of rain,” he said.
“The water is rising all along the river.
“Bedgerabong is still isolated and the water is spreading this side of Jemalong Weir.”
The Lachlan Valley Way to Condobolin is closed at the 17 mile and 21 mile.
Forbes to Parkes is still open but with traffic control – there is water over the road at Tichborne.
Forbes to West Wyalong is also open but there is traffic control as there is water over the road.
Forbes to Cowra and Forbes to Eugowra are both open, water over the road is signposted.
Forbes to Bogan Gate is open.
According to Weatherzone, there is a 90 per cent chance of 5-10mm Tuesday and 1-5mm in showers Wednesday and Saturday.