Sopping catchments are replenishing Victoria’s dams at a phenomenal rate, with Melbourne’s water storages likely to top 80 per cent of capacity by year’s end - their highest level in 15 years.
Statewide, the picture is similarly bright, with no region going thirsty.
The rebound from the worst drought on record has made for stunning recoveries at Lake Eppalock, which ran dry in 2007 but is now nearing capacity, and at Lake Eildon and Lake Hume.
Water in the Coliban system, which feeds Bendigo, has increased from a skinny 10 per cent five years ago to the mid-90s; Ballarat’s supply is nine times greater; Geelong’s has risen fourfold.
A wet summer and autumn has ensured that sodden catchments are making the most of winter rains with the run-off into Melbourne’s key four storages - the Thomson, Upper Yarra, O’Shannassy and Maroondah dams, which harvest up to 90 per cent of Melbourne’s needs - already having exceeded the winter average of 175 billion litres.
Stream flows have been so impressive that the Thomson, critical for drought-proofing the capital, is at 65 per cent, with no water drawn from it since October 2010. In one week earlier this month, it ”banked” around 20 days’ supply.
”It’s our superannuation, if you like,” says Melbourne Water’s Nicolas McGay. ”It’s for the long term. The other nine Melbourne storages are our daily withdrawal accounts.”
Typically, the ”filling season” of winter and spring lifts Melbourne’s total supply by almost 10 percentage points, and winter rainfall in the catchments is already tracking above average. Currently, the supply is nudging 73 per cent of capacity, after falling to a low of 25 per cent on June 25, 2009. The trajectory suggests it will cross levels last reached in 1997, although Mr McGay will only say that the storages are ”in a great position”. ”They’ll certainly rise from here.”
The transformation from the despair of the drought years has been marked by bolstered environmental flows and an easing of water restrictions, as well as the development of myriad regional projects that link supplies. The turnaround has come despite the demands that regenerating forests post-Black Saturday have put on rainfall in Melbourne’s catchment, a third of which was burnt, and well ahead of completion of Victoria’s Wonthaggi desalination plant.
So good has been the statewide revival that water is being released from the Dartmouth Dam - the Goliath of the state’s water infrastructure at four times the size of the Thomson - as well as the Hume and Eildon to make room for future stream flows and rain, and as a means of mitigating flood risk.
Even so, water chiefs are not inclined to crow, with memories seared by the spectacular fall in storage levels during the worst of the dry years. In just 18 months from 2007, Melbourne’s water supply halved, plunging from above 60 per cent to just 29 per cent.
Graeme Turner, the executive director of water resources for the Department of Sustainability and Environment, acknowledges an uncertain future. ”We do plan for severe droughts and we generally get a reasonable recovery after them,” he says. ”But history doesn’t tell us what’s ahead. There are no guarantees.”
At the height of the drought, 436 Victorian towns were subject to restrictions, 291 of them on the most extreme stage four. Today, the water consumption of 26 centres (including Melbourne) is restricted, with the current highest level imposed (stage three) applying to just two - Sebastian and Raywood, which are just north of Bendigo and in the process of being connected to that city’s supply.
Although Melburnians’ daily water consumption for all uses (residential, business and industry) has been creeping higher since the drought broke, it remains around 22 per cent lower than in the ”profligate” 1990s - 998 megalitres a day versus 1320 million megalitres in the years 1992-98.
