Water released from central Queensland mines into a major river has been monitored, and nothing of concern has been found, the state government says.

Deputy Premier Jeff Seeney last year announced the pilot release of legacy mine water from BHP-Mitsubishi Alliance mines would take place during the wet season.

He has told parliament that about 10 gigalitres have been released into the Fitzroy River, which flows through Rockhampton, after torrential downpours in January caused widespread flooding.

"These releases were heavily monitored to provide us with the data to make assessments about the releases and their impact," Mr Seeney said on Thursday.

The deputy premier said none of the monitoring sites found anything of concern.

The idea came under fire when it was announced last year, with opposition environment spokeswoman Jackie Trad criticising the release of "dirty water" into rivers.

"Mr Seeney is forcing his dirty water deal down the throats of the people of Rockhampton with no consultation and no appropriate planning or process," she said at the time.

However, Mr Seeney told parliament on Thursday environmental concerns were not based on any scientific evidence.

"These claims have been aimed at doing nothing more than alarming the people of the Fitzroy Basin," he said.