A Murray Darling Basin Authority official admits higher flows in the Tumut River to feed the environment would be damaging.
A draft constraints strategy will be released in a week and ideas will be sought on which works will best deliver the higher flows intended under the Basin Plan.
MDBA Executive director Jody Swirepik says last year it became clear environmental water can't be delivered at the times and places most needed because of constraints in the system.
Ms Swirapek says they include the low lying Mundarlo Bridge near Gundagai, and outflow limits from Blowering Dam into the Tumut River.
"That is one of those places in the system where there is only a limited channel capacity and it would do a reasonable amount of damage to run that river higher," she said.
"But this is exactly the thing we need to draw out through this process to understand which things might be reasonable to change and which things aren't."
The draft constraints strategy will focus mainly on the southern basin and the MDBA wants to hear local views on river management rules and other physical limits to higher environmental flows.
Jody Swirepik says it will be up to basin governments to decide where to fund works to address the constraints.
"An example might be a low lying bridge or the outlet capacity of a dam or the fact that we have rules that run the river and confine it nearly all the time to within its banks," she said.
"So we just want to test the boundaries of those rules."
"Understanding what the issues are and what might be done to address those and then whether you move into an implementation phase in a couple of years time."
The Tumut River Landowners Association wants a speeding up of works to stop erosion from rapid fluctuations in river levels for environmental and irrigation releases.
Spokesman Peter Luders says the only thing that works is rocking the banks but a new management plan has limited the practice.
Mr Luders says governments who have committed so much to the Basin Plan should consider spending money rock walling the Tumut River to stop the erosion of metres of valuable river flats.
"They could have done it very comfortably indeed, if they'd had a mind to do it," he said.
"By not doing it you're creating a devastating affect on the environment."
"We've now got massive gravel bars all through the river."
"All of the erosion of the river banks creates these bars."
"They tend to produce islands in the centre of the river and that increases the rapidity of the erosion."
"They can use the material in that and push it up against the bank and it could be a very, very cheap source of erosion control."
The Wakool Landowners Association is frustrated with the MDBA's consultation on the constraints and is fearful that flooding of river farms will be the outcome.
Spokesman John Lolicato says after 15 meetings this year with the Authority, there's only now a realisation that the impact of higher flows is going to be significant in the Edward-Wakool system.
"We've provided an awful lot of information over that period back to May and we just don't seem to be making any difference," he said.
"There's a political imperative there to get this water down and logic and common sense doesn't seem to take any place."
"Like we've been involved with this process since the Living Murray days and we've pointed out the fact that the river can only sustain so much water before it goes out of bank."
"And when it goes out of bank is when it creates third party impacts."