The report card for the region's waterways was revealed on Wednesday, showing the grades for most south-east Queensland catchments either improved or remained the same as last year.

Professor Stuart Bunn, from the Healthy Waterways and Catchments science committee, said the largest improvements in the region were in coastal catchments.

"Most (climbed) from C (fair) to B (good) aside from Noosa which retained the highest catchment grade in south-east Queensland (A-)," Professor Bunn said.

Moreton Bay retained its B+ rating, with most bay zones maintaining the same grade or experiencing only marginal declines.

"The majority of western catchments, which are highly valued for food production and drinking water, saw little to no change aside from slight improvements in mid-Brisbane and the Bremer," Professor Bunn said.

He said the improvement in grades across the region was largely due to a 70 per cent decrease in the amount of sediment pollution entering the waterways, associated with below average rainfall this year.

But despite the decrease, about 15,000 dump trucks worth of sediment was still entering the waterways.

The Queensland government has so far failed in its attempts to pass its tree clearing laws, which were designed to limit sediment run off.

Professor Bunn said sediment pollution remained the number one pressure threatening south-east Queensland waterways.

"The amount of sediment pollution entering the waterways is driven by rainfall, but is also strongly affected by the condition and management of the land," he said.

"This year, the upper catchment region suffered below average rainfall, and as a result pollutant loads declined.

"This reduces the threat downstream and the condition of coastal waterways tends to improve during these times."

Professor Bunn said the primary source of sediment pollution in rural areas was stream bank and gully erosion, while in urban catchments, sediment runoff from poorly managed construction sites was a key issue.

The 2016 Healthy Waterways and Catchments Report Card was released on Wednesday at four locations, revealing the condition of south-east Queensland's waterways.

The worst result was awarded to the upper Brisbane catchment which received a score of D, unchanged from its 2015 condition.

The mid-Brisbane, Lockyer and Bremer catchments all received a score of D+.

South-east Queensland waterways generate $6 billion through tourism each year, and about $2-3 billion through recreation.

Queensland Environment Minister Steven Miles said the release of sediment from urban areas was an ongoing challenge and the results highlighted the need to accelerate its efforts.

"We also continue to work closely with the horticulture and grazing industries on best management practice programs," Dr Miles said.

"These are important programs which aim to keep valuable agricultural soil out of our waterways and in the paddocks where it belongs."