FIFTEEN mines are releasing water into the Fitzroy Basin following heavy rainfall last week.
Minister for Environment and Heritage Protection (EHP) Andrew Powell said mines were permitted to release water during times of high water flows under their Environmental Authority (EA).
"This has been standard practice for many years," he said.
"For example following heavy rain in early March last year 19 mines released water into the Fitzroy catchment."
Mr Powell said EHP was working with the Department of Natural Resources and Mines to monitor all releases and ensure water quality is maintained.
However, environment group Save the Reef yesterday labelled EHP as "irresponsible" for approving water releases without setting maximum limits.
"We know that six mines were approved to release more than 712 million litres into the Fitzroy catchment on 25 and 26 January," Save the Reef spokeswoman Dr Libby Connors said.
"Another 35 mines were permitted to release water without giving their volumes.
"If they release at a similar rate it will be adding 4800 megalitres of additional water, that's almost five billion litres into the already flooded Fitzroy River system."