The Department of Regional Development, Manufacturing and Water has been warned that a billion dollar-plus dam upgrade may not meet its deadline because it does not properly monitor progress or safety compliance by private owners.

Queensland Audit Office's report has urged the department to improve its documentation and punishment of non-compliance, revealing one dam safety report due in 2007 is still outstanding.

Under a plan launched in 2005, private owners have been tasked with upgrading dam spillways based on their capacity to safely release floodwaters, with eight due to be completed by 2025 and 30 by 2035 at costs estimated at $3.1 billion.

"The department is not effectively monitoring progress to ensure all the upgrades will be completed by the upcoming 2025 and/or 2035 deadlines," the QAO report says.

"The department ... does not effectively monitor compliance with all its safety requirements.

"It uses spreadsheets to monitor compliance but the individual spreadsheets are not up to date, complete or accurate.

"This makes it difficult for the department to track whether dam owners are conducting and providing key reports on dam safety inspections on time."

The QAO encouraged the department to use "the full range of enforcement measures" at their disposal to punish serious non-compliance, revealing some safety reports were years overdue or not provided at all.

The report says Lake Mitchell Dam in the state's far north had a safety review due in 2007 but has still not been received.

In the state's northwest, Chinaman Creek Dam's report was received more than four years after it was due and Rifle Creek's was more than three years late.

"The department focuses on voluntary compliance but has been reluctant to use enforcement measures such as penalty infringement notices or court action when needed," the report said.

"It has not made use of the available enforcement actions even though there are examples of owners consistently not providing the legislatively required safety notifications and reports on time.

"It cannot assess whether the dams are compliant with the safety standards if the safety reports are considerably late or not provided at all.

"These gaps in information gathering, systems, monitoring and enforcement practices limit the department's effectiveness as a regulator."

The report's recommendations include the department revising flood capacity guidelines, requiring dam owners to advise it on the progress of spillways scheduled for upgrade.

The department was also urged to review how often it conducted risk assessments and flood capacity for dams, revise its process for selecting site audits, improve its documentation of inspections and safety reports and set clear thresholds and more effective enforcement for non-compliance.

Australian Associated Press