Councils were urged to cooperate more closely to stop the Dodder River becoming a dump.
Three local authorities in the Dublin region were accused of failing to protect one of the city and county's major rivers.
Criticism of the councils was expressed by the Dodder Action Group.
The group has organised hundreds of volunteers to clean up the river tomorrow.
It will be the third annual volunteer effort to take rubbish from the river and its banks.
But the time has come for councils to stop expecting volunteers to do the cleaning for them, the group claimed.
In preparation for tomorrow's clean-up, a group of volunteers cleaned up a section of the Dodder near Anglesea Bridge in Donnybrook yesterday and built a mountain of the waste to let the public see the extent of the problem.
A spokesperson for the group declared: "The group will, for the third time, field hundreds of volunteers along the river banks on Saturday, from Tallaght to Ballsbridge as part of An Taisce's Spring Clean.
"But we ask when will the cleaning end and the strategy begin?"
The group called on South Dublin County Council, Dublin City Council and Dun Laoghaire Rathdown Council to form a single committee to manage the river together.
The group wants:
l Compactor bins right along the river, similar to those recently installed by Dun Laoghaire/Rathdown.
l Removal of recycling plants from the river banks, such as those in Milltown in the Dublin City Council area.
l Monitoring and policing of the dumping of material into the river, particularly in those areas in south Dublin which are less frequented.
l Ensure access to the river by managing vegetation to prevent the formation of 'tunnels' which exclude light, trap waste, and limit visibility.
l Proper sealing of the former Bohernabreena dump where breaches still occur.
l Engage in an intensive clean of those areas upriver that are full of junk.
The group referred to proposals for the development of a greenway amenity area being developed along the course of the Dodder.
The group declared: "There is little point in developing a Dodder Greenway if the river is a dump."
Volunteers for tomorrow's big clean up on the riverbanks are meeting at the following locations: Milltown, Orwell, Firhouse at 10am, and Rathfarnham, Knocklyon, Whitestown Stream at 11am.
The Dodder Action Greenway statement and membership details are on www.dodderactiondublin.com.
The group is contactable on Dodder Action Facebook/Twitter and firstname.lastname@example.org.