SES crews are on alert and police are on patrol in low-lying areas as creeks and rivers in the Ipswich area begin to rise.
Just after midday, Somerset Regional Council advised that The Brisbane Valley Highway at Gallanani Creek between Esk and Toogoolawah had been closed due to flooding.
A short time later, the same highway was also blocked due to flooding near the Ramblers drop zone at Boundary Creek, Toogoolawah.
Police are on site.
There are reports of water over the road at the Six Mile Creek Crossing on Redbank Plains Rd.
The road is still open but motorists have been urged to take care.
The Warrego Highway remains open between Ipswich and Toowoomba, with the Lockyer Creek sitting just above 4.3m - well below the overflow level of just over 8m.
Laidley Sergeant Jim McDonald says police are keeping a close eye on all creeks in the area, however rain so far has not been as severe as it was in January.
"We've had moderate rain all morning but nothing you'd call heavy," Sgt McDonald said.
"We've had about 100mm of rain in the catchment over six hours."
SES crews have been sandbagging vulnerable buildings in low lying areas of Rosewood and Laidley, including St Brigid's School, where Ipswich crews delivered about 30 sandbags to protect a classroom.
Lockyer Valley SES controller Gary Dorr says local run-off is the cause of most flooding so far.
"It certainly will be monitored through the afternoon," he said.
"If the rain continues at this rate then further flooding is a possibility."
Ipswich residents have been warned the city could receive between 100mm and 200mm of rain on Monday and Tuesday.
Colleges Crossing was closed Sunday night after Seqwater increased Wivenhoe Dam releases, with the aim of returning the dam to 88% before heavy rain arrived.
Amberley weather station had recorded 25mm before 9am and a further 5mm by 10am, however there were some much heavier falls at Esk and Somerset Dam, which both registered just under 50mm by 9am Monday.
There were also overnight falls between 40-50mm in Springfield and Mt Crosby, with a huge band of thick raincloud still lingering over south-east Queensland during the day.
Police say there are already reports of water over Churchbank Weir Rd and Queen St at Harrisville.
Of course, the Brisbane River has risen above the level of Colleges Crossing and Mt Crosby Rd is blocked.
Residents have been urged to stay informed by listening to local radio and checking the BoM website.
According to Seqwater, the Wivenhoe Dam catchment will receive up to 100mm of rainfall and the Somerset Dam catchment between 100mm to 150mm on Monday and Tuesday.
The Bureau of Meteorology is sticking by its earlier forecast for heavy rain on both days.
"Locally heavier totals in excess of 200mm (are) possible particularly near the coast and about adjacent inland areas," the warning read.
"Periods of more intense rain may deliver totals of up to 100mm over a shorter duration of up to six hours."
On Sunday, Somerset Dam was at 100% and levels were being maintained through operational releases.
Releases may increase after further rain and will be managed by the Seqwater Flood Operations Centre.
Wivenhoe Dam was at 90% on Sunday, and releases were increased from 150 to 280 cubic metres per second.
Twin Bridges and Savages Crossing will remain closed because of the releases.
Phone the State Emergency Service on 132 500 for flood and storm assistance.