Thousands of red gums on the brink of death have been saved — temporarily at least — after 17 billion litres of water were released from dams to boost Victoria's ailing Murray wetlands.
The water sparked an immediate response from the environment. Hundreds of frogs spawned, waterbirds arrived and tortoises laid eggs.
Many of the areas targeted had not seen water for two years. Numbers of waterbirds have dropped by two-thirds during the 11-year drought.
About 10,000 red gums — some 500 years old — would have been dead within a year had the environmental flow not occurred, said Dr Jane Doolan, from the Department of Sustainability and Environment.
Water has flowed through the wetlands and creeks for two weeks.
Recent studies have found that 70pc of red gums in northern Victoria are dead or dying.
This month's watering will cover only 900 hectares, or 1.4pc of the State's river red gums.
The environmental allocation consists of 6 billion litres from the Murray-Darling Basin Commission's Living Murray program and 11 billion litres from Victoria's pool of environmental water.
It is flooding the Gunbower Wetlands north-west of Echuca; Little Lake Boort west of Echuca; the Lindsay-Walpolla site in the Mallee; and the Reedy, Kinnaird, Black and Moodies swamps near Shepparton.
State Environment and Climate Change Minister Gavin Jennings said the water had prevented ancient forests from turning into red gum graveyards.
"Some of the river red gums were alive when Columbus discovered the Americas," Mr Jennings said.
"They are part of all Victorians' heritage."
The Murray remains bleak, however. Dried-up wetlands and creeks in the lower parts of the river in South Australia have started to turn acidic and leach heavy metals, including high amounts of aluminium and arsenic, zinc and lead.
The $12.9 billion water package to save the Murray has been finalised, but water specialist Mike Young, from the Wentworth Group of Concerned Scientists, has warned that time is running out and the Federal Government must act quickly to use $3 billion to buy back the 1500 billion litres the river system needs to be healthy.
The Bureau of Meteorology winter forecast for the basin, released last week, suggested another dry El Nino phase could be on the way and there was little hope of good rainfall.
The Basin Commission's chief executive, Dr Wendy Craik, described the situation as not terribly optimistic, but dam levels were slightly higher now than at this time last year.
It is hoped the northern Victorian environmental water will help threatened species such as the regent parrot, the inland carpet python, the barking owl, the painted snipe, the white-bellied sea eagle and the growling grass frog.
It is hoped the royal spoonbill, the great egret and the glossy ibis will benefit from the watering in the Gunbower Wetlands.