Residents in south-east Queensland are being urged to lower water usage after dam levels fall to levels not seen since the millennium drought. 

Wivenhoe Dam has fallen below 40 percent capacity, with State Water Minister Glenn Butcher saying despite heavy rainfalls from La Nina weather system, it wouldn’t guarantee dam levels rising.

New awareness campaigns have been launched to encourage reductions in water usage by residents, Mr Butcher says if things don’t change water restrictions could be in place as soon as December.