In further proof that Brisbane's waterways require urgent attention, the report laid bare astonishing figures, showing the volume dredged from the Brisbane River in 2013 was almost five times that for maintenance during an average year.

"In early 2013, approximately 1.4 million cubic metres of silt and sediment accumulated in the Port of Brisbane channels and berths as a result of flooding rains and multiple dam water releases within the Brisbane catchment," the report says.

"This volume equates to more than 920 ship loads of dredged material and took 20 weeks to remove."

Furthermore, the cost of removing the silt was felt by the public not only in maintenance costs, but also in terms of supply at the petrol bowser.

"Some deep draft vessels, including oil tankers, were delayed by up to five days as a result of both events," the Port of Brisbane Authority last night confirmed.

The scenario happened in both 2011 and in 2013.

Brisbane's port channel is dredged to 15 metres and the ships need a 2.4 metre draft between the bottom of the vessel and the bay floor. In the top section of the Brisbane River they need only a one metre draft.

Page 21 of the Ports Australia study says additional surveying and dredging work was "vital" to ensure "large vessels could berth safely".

Port of Brisbane Authority senior staff have quietly expressed concerns to government that a permanent remedy is needed.

Now Queensland councils – backed by Premier Campbell Newman – have crushed plans by Natural Resources Minister Andrew Cripps' department to block local councils being on a Brisbane River Improvement Trust.

That now means a new Environmental Taskforce, chaired by Environment Minister Andrew Powell, will be announced before Christmas to begin this work.

That announcement could come after State Cabinet on Monday and could include a decision to begin a study of a new dam for Southeast Queensland at Linville, north of Somerset Dam.

The Environmental Taskforce is likely to include the Port of Brisbane, the two water utilities - SEQ Water, SEQ Catchments - Healthy Waterways, State Government and South East Queensland councils, several sources said.

For the first time, Queensland Urban Utilities, Unity Water, the Port of Brisbane Authority will contribute to the cost of battling serious erosion upstream in the Lockyer Valley.

They will together fund anti-erosion projects upstream - before they become more costly downstream projects, which is a scheme already in place in locations such as New York City.

Queensland Conservation Council executive director Toby Hutcheon applauded the new approach.

"The water authorities in New York City fund erosion-prevention for farmers in the Catskills Mountains," Mr Hutcheon said.

"The Catskills Mountains are the catchment for New York's water supply. So what they do is give money to farmers to look after the land and stop erosion and as a result when the water comes in to their treatment plants it is cleaner and cheaper to process to provide the water to residents.

"And it is that exact same process we are talking about here.

"We are welcoming this, because it is progress on a key goal that we have sought, which is the saving of Moreton Bay and reducing pollution into the bay."

Previously, disappointed councils walked-out of the Environmental Taskforce in October after 18 months of work to put the body together.

Bitterly-disappointed Brisbane Lord Mayor Graham Quirk made the announcement on October 29, calling it a "bit of a mess".

Brisbane's drinking water supplies were threatened when the Mt Crosby Water Treatment Plant was blocked by silt in January 2013.

In June 2013, five groups - SEQ Catchments, the Queensland Farmers Federation, Queensland Conservation Council, Healthy Waterways and Growcom - released a joint-study showing the following:

-          Millions of tonnes of sediment each year come from the Lockyer Valley, which provides 35 per cent of Queensland's vegies, estimated at $160 million a year;

-          If erosion blocks Mt Crosby Treatment plant, replacement water comes from Tugun's desal plant at far higher prices ($678 per mega-litre, compared to $64 per mega-litre);

-           It would cost $2 billion for a new pipe to connect Wivenhoe to Mt Crosby treatment;

-          Sediment into Moreton Bay effects a $24 commercial fish industry and a $150 million recreational fishing industry; and

-          The Port of Brisbane spends millions of dollars each year on dredging.

The new Environmental Taskforce will set a strategic plan and prioritise anti-erosion plans on an Moreton Bay catchment priority, rather than on an individual council priority.

Failures to find a consistent policy to address the problem were revealed by Fairfax Media in March 2013.  

Environment Minister Andrew Powell was unavailable for comment on Thursday.