A proposal to significantly boost environmental flows to the Snowy River was blocked in Cabinet by former NSW primary industries minister and ALP powerbroker Ian Macdonald before his sacking, Crikey has learnt.

The Mowamba Viaduct, which connects the Mowamba River, a tributary of the Snowy downstream from Jindabyne, to Lake Jindabyne, is one of the biggest obstacles to efforts to halt the steady degradation of the Snowy River under the $425 million inter-governmental agreement between the Commonwealth, NSW and Victoria.

Since then, NSW has systematically subverted the agreement.

Crikey understands that, before Macdonald’s sacking by Nathan Rees on November 17, water minister Phil Costa took a submission to Cabinet that the Mowamba Viaduct be decommissioned, albeit not immediately.  The viaduct, which delivers up to 40GL of water a year from the Snowy to the Snowy Hydro Corporation, was decommissioned from 2002-06, but recommissioned — some say having been expanded — thereafter, with the intention of “repaying” Snowy Hydro environmental flows sent down the Snowy during the decommissioning period.  The Mowamba water is used to operate a mini-turbine at Jindabyne Dam.

Snowy Hydro’s insistence on the Mowamba “repayment” continues to deprive the Snowy of high-quality, seasonally and naturally variable water flows, leaving the river closer to degradation now than when John Howard, Bob Carr and Steve Bracks signed the original IGA to “save” the Snowy.  Carr and Bracks announced the closure of the viaduct in 2002, only for NSW to announce it would be recommissioned in 2005, shocking Bracks, who said his understanding was that it would remain non-operational.

In response, Macdonald, then primary industries minister, declared that NSW had never agreed to permanently decommission the viaduct.

The decommissioning has long been a goal of Snowy campaigners disgruntled that the IGA, and hundreds of millions of dollars, have not prevented the further degradation of the river.

Costa’s Cabinet submission was said to have been defeated when Macdonald, a long-time supporter of Snowy Hydro, strongly objected to the proposal.  Macdonald has been a dogged advocate for Snowy Hydro’s interests for years, backing its hare-brained cloud-seeding project and its privatisation, which was derailed by the Howard government.

Macdonald was sacked by  Rees as part of the then-Premier’s unsuccessful attempt to purge his ministry in November.  On Tuesday he was appointed by Kristina Keneally to the ministries of mineral and forest resources, state and regional development and the Central Coast.  Costa was reappointed to the water portfolio but lost his former regional development portfolio to Macdonald.