KEY POINTS:
Australia is beginning to feel the political and economic heat of climate change, fuelled by the drought that continues to grip vast tracts of the eastern seaboard.
Water has become the single biggest issue facing the nation's largest cities, its regional centres and the farmland that both feeds its population and earns billions of dollars in export income.
Rivalry for limited and endangered supplies, and fears for the surrounding ecosystems this week burst on Victorian Premier John Brumby as protesters from three separate campaigns united to disrupt the opening of State Parliament and force the closure the public gallery.
Brumby had to be escorted from the building after failing in an environmental statement to lower the heat of opposition to three key projects that included a programme to "drought-proof" Melbourne.
PIPING WATER
As much of Victoria continues to dehydrate in one of the worst droughts in recorded history, the idea of piping water from parched farmland to the suburbs of Melbourne was never going to win hearts west of the Great Dividing Range.
Brumby inherited the scheme from predecessor Steve Bracks, and is pushing ahead with the A$1.8 billion ($2 billion) plan regardless of the fury of irrigators, regional towns and other protesters whose anger has otherwise kept the state out of the Federal Government's plan to take control of the ailing Murray-Darling river system.
The plan is to take water from the foodbowl of the Goulburn Valley and pipe 75 billion litres to Melbourne's big Sugarloaf reservoir, where it will help ease the crisis facing Australia's second-biggest city.
It will tie in with the huge desalination plant to be built southeast of Melbourne, joining others either planned or in operation in Perth, Sydney, the Gold Coast and Adelaide.
There is a major trade-off: a vast upgrade of the Goulburn Valley's old and inefficient irrigation system, which loses about half of the 1200 billion litres of water it carries every year to evaporation and leaks.
The State Government argues that by sealing the system it will save about 225 billion litres of water, increasing supplies to farmers, rural towns and cities, and the 3.6 million people of Melbourne.
The water will be split three ways: a third to irrigators, a third to Melbourne, and the rest to parched wetlands and rivers to help revive their flows and storages.
The Government says that without its help, farmers could never afford the cost of restoring the valley's complex of water channels, and that handing Melbourne a third of water that would otherwise be lost is a small price to pay for much greater protection against drought in the future.
Regional Victoria sees the plan as theft.
Led by local politicians and a protest group called Plug The Pipe, they claim that the already overstretched Murray Darling system cannot afford any further losses, and that Melbourne needs to address its own inefficiencies and seek new supplies elsewhere, notably the planned desalination plant.
They say that like other groups opposing desalination and the dredging of Port Phillip Bay, they have been steamrollered by an "arrogant" Government, and that the plan will ensure Melbourne always has first call on the valley's water.
Irrigators are also furious at the Government's intention to return Lake Mokoan, near Benalla in the state's northeast, to wetlands, cutting off its water.
While farmers say the loss of water from the lake - an artificial storage, dammed in 1971 - will hammer production, the Government argues that about 50 billion litres is lost to evaporation a year.
By restoring the natural wetlands, it says, about 44 billion litres of water a year will be fed into the Murray, Snowy and other rivers.
DESALINATION
The Government has already been taking land by compulsory acquisition for its planned A$3.1 billion desalination plant at Wonthaggi, amid powerful opposition from environmentalists.
It says the plant will produce 150 billion litres of clean water a year from the ocean, dividing it between Melbourne, the southern port city of Geelong, and the South Gippsland region.
Designers also say the plant will be "greenhouse neutral", with the power consumed in its operation offset by an expansion of renewable energy projects either planned or already under way throughout the state.
Seawater will be pumped in through a pipeline extending 1km into Bass Strait, and stripped of its salt by reverse osmosis.
This produces concentrated salt water - containing about twice the normal levels of salt found in seawater - which will be pumped back into the ocean at about 1C warmer than the surrounding sea.
The Government says this will avoid damage to the environment and marine life, which will be further protected by very low intake velocities ensuring even small fish can swim in and out without harm.
The plant, Australia's biggest and one of the largest in the world, will supply about a third of Melbourne's annual water requirements.
But protesters claim the plant is an overly expensive and environmentally damaging option which Victoria does not need.
They say Melbourne's water supplies could be better secured by efficient planning and management, providing a more effective long-term answer than costly new sources.
They are supported by anti-pipeline protesters, who share similar concerns and argue that the city's problems are of water management, not water volume.
Critics also dismiss the Government's claims that the plant will not damage the environment, and are demanding further studies to ensure that marine life will not suffer.
Protest groups, led by Your Water, Your Say, claim that despite Government assurances, the concentrated brine produced by the plant will hammer local fish populations and in turn damage life higher up the food chain, including fairy penguins, fur seals and migrating whales.
Locals are also angry at the compulsory acquisition of land for the 40ha site, and say that even with assurances that no new wind farms or other power plants will be built nearby, a nationally significant, pristine coastline will become an industrial park.
And opponents have argued cheaper, more efficient and less damaging options are available, including piping Tasmanian water across Bass Strait.
DREDGING THE PORT
Although not directly affecting the state's precarious water supplies, the dredging of shipping channels in Port Philip Bay has sparked further fears for the marine environment and united protest group Blue Wedges with anti-pipeline and anti-desalination activists.
The Government says dredging the channels is needed because of a global trend towards larger, deeper and more economically efficient container ships, and that 44 per cent of the world's container fleet could be blocked from Melbourne if the port is not deepened.
It says that every day exports worth A$90 million leave the port, and that dredging will bring direct benefits of almost A$2 billion without damaging the bay's environment.
The A$970 million project has been approved by Federal Environment Minister Peter Garrett, following strengthened conditions designed to protect wetlands and migratory and threatened species of animals and birds.
But court action by the anti-dredging group Blue Wedges has delayed the start of operations by the huge Dutch dredger Queen of the Netherlands, which has been idle at a reported cost of A$250,000 a day since February 1.
An appeal against the dredging will be heard on February 20.
Blue Wedges claims sediment from the dredging will create an environmental disaster as it swirls across the bay with the tides, smothering marine vegetation and disrupting the food chain.
Opponents claim that the impact will damage rivers, fisheries, wetlands and beaches, and possibly hit tourism through large tidal movements.
Blue Wedges disputes Government claims that pollution will be contained, warning that Port Phillip Bay will become a toxic dump.
