Colleges Crossing during last month's water releases from Wivenhoe Dam.
Dam operators will release 25 per cent of the Wivenhoe's drinking capacity to mitigate against further flooding this year.
It means Colleges Crossing will be closed for at least nine days from Monday during the release, forcing motorists to use the nearby Mt Crosby Weir crossing.
The Moggill Ferry is expected to keep operating, but the upcoming closure of Colleges Crossing is the seventh at the site since October last year.
The SEQ Water Grid manager said in a statement minor tidal flooding along the Brisbane River would not be increased by this weekend's release.
"It is expected that this controlled release will run for nine days in order to take best advantage of the current mild weather, falling tides and the limited flows into the Brisbane River from other sources downstream," he said.
Twin Bridges and Savages Crossing will be closed along with Colleges Crossing.
The water grid authority said other alternatives were looked at but the current release plan was the best solution.
"While a longer release pattern has been considered, it has not been recommended by Seqwater, owing to the need to take best advantage of the current weather, tides and flows into the Brisbane River," the manager said.
"Also, in order to keep Colleges Crossing open, the release pattern would need to be effectively doubled and would mean that both Twin Bridges and Savages Crossing would be impacted for at least 18 days and longer if there was rainfall in the Brisbane area or at the dam site."
Natural Resources Minister Stephen Robertson, who announced the plan last Sunday, said heavy rain was forecast until April and the release was a necessary precaution.
"Seqwater has advised that a reduction in Wivenhoe's Dam storage level to 75 per cent of its full supply level provides appreciable flood mitigation benefits ahead of any major rain events in the remainder of the wet season," he said.
About 2.6 million megalitres of water flowed into the Somerset- Wivenhoe system in January's floods, more than double that of 1974.
More 2011 flood stories: www.QT.com.au