THE inter-governmental agreement to return water to the Snowy River was a well-constructed sham, according to the Environmental Defenders Office.

The revelation has sent governments ducking for cover with the NSW, Federal and Victorian governments all failing to respond to the claim.

The Snowy River Alliance has labelled the situation "a national disgrace" and says the river is "in its death throes".

SRA has also called for a Senate review "in light of what seems to be a legislative fraud perpetrated on the Australian public".

Legal advice provided by the EDO to SRA said governments were not legally bound to the environmental objectives in the relevant agreements.

"It appears that the legislative and contractual framework governing the present Snowy Scheme has been carefully crafted in an attempt to ensure there is no legally binding obligation on the relevant governments . . . (regarding environmental flows and outcomes)," the advice said.

Snowy River Alliance chairman John Gallard said the Snowy received 4 per cent of natural flow this year when the agreements had specified 15 per cent.

"The three governments have deceived the Australian public and the Snowy River communities," Mr Gallard said.

The Bracks Government had provided written assurance to SRA in 2002 - seen by The Weekly Times - that the agreements were "legally binding", but refused to provide a copy of the legal advice it said it had sought.

Mr Gallard said if the Victorian Government did not now produce the advice, it would "prove the Bracks' Government gained power fraudulently by misleading the community over the Snowy".

The EDO advice also said the Snowy Heads of Agreement was unlikely to qualify as a legal "agreement", as was the Snowy Water Inquiry Outcomes Implementation Deed.

Independent MP for Gippsland East Craig Ingram, who was involved in negotiating the deal, said he and SRA had chosen the compromise - the "political deal" - rather than a legal challenge testing constitutional law.

He said the Victorian and Federal Governments could force NSW to honour much of the agreements via legal avenues.