In southern Victoria, as in the rest of Australia, we have historically relied on rivers to supply the water we need in our homes and our towns. Rivers have been a source of life and joy for generations.
But as our water demands have grown and a hotter, drier climate has reduced the water available, we have had to turn to other sources. In 2020, 25 per cent of our water came from the desalination plant at Wonthaggi and 10 per cent came from recycled water. So our problem is that both trends - increasing demand and decreasing supply - are intensifying.
Advertisement
Compared to the historic average, the amount of water flowing into our rivers, lakes and wetlands has declined by as much as 21 per cent over the past 10-15 years. Under a medium climate change scenario, these declines may continue by a further 8-22 per cent by 2065. Under a high scenario, that could rise a further 40 per cent.
The Victorian government's Sustainable Water Strategy deals with the next 10 years of water management for southern Victoria. This is a region stretching from the Great Divide to the coast, from East Gippsland to the Otways. The strategy considers how the amount of water flowing into our rivers has declined, how demand will grow and how competing uses must be balanced with the essential needs of the landscape.
We already have a preview of declining water supplies - somewhere between 8 and 40 per cent over the next 45 years. But as Victoria's population grows, demand might be 1.7 times higher over the same time period.
On the current trajectory, by 2065, over half of the water southern Victoria needs does not currently exist. The Sustainable Water Strategy is founded on one key premise - rivers cannot give up any more water to meet future demand. It is based around a strategy of water substitution.
That essentially means that if we manage to grow water supplies with greater use of stormwater, desalination and fit-for-purpose recycled water, then those sources can substitute water taken from rivers (known as extraction). Water that used to be taken from rivers would then be free to flow.
This is a reasonable approach for addressing growth in consumer usage in our homes and cities. But in this deal, water for rivers is far from guaranteed. Instead of a plan to increase river flows, waterways are dependent on the leftovers after industries and cities have had their fill. What's worse is that any water saved for rivers is already playing catch-up with the impacts of climate change (currently a 21 per cent decline in water supply). That's not good enough. Rivers need a better answer to the question of their long-term survival than 'maybe'.
As it stands, the Draft Sustainable Water Strategy presents a big 'maybe' to the future of southern Victorian rivers.
- Tyler Rotche
We need enough water to let rivers be rivers, and that means ensuring connectivity. In order to achieve connectivity, rivers need to be connected from upstream to downstream, from the channel to the floodplain forests over the banks, and between surface water and groundwater. Connectivity for our rivers is essential for many reasons. These include allowing fish, turtles and platypus to move freely, as well as allowing life-giving sediments to keep moving, bringing adjoining wetlands and riverside forests to life, recharging groundwater supplies.
As it stands, the Draft Sustainable Water Strategy presents a big 'maybe' to the future of southern Victorian rivers.
If we can grow our water supplies to sustain nearly double today's demand, then maybe there will be some water leftover to flow through rivers.
What we need instead is a plan that works backwards from waterway health. This is the approach that was put forward (but only half-heartedly implemented) in the Murray-Darling Basin Plan.
A responsible plan would begin by using the best science to identify an 'environmentally sustainable level of take' - a baseline for how much water needs to be kept in rivers for them to thrive over the long-haul. Not just river survival but ensuring the foundational conditions of a healthy waterway. Next, we need to take actions that reduce extraction, so enough water is kept in our rivers.
It requires a sensible and courageous government that recognises the current level of privatisation of our water cannot go on in a drier climate. Some water will need to be bought back from license-holders to confront historic over-extraction. Right now, this isn't even on the table.
Finally, this water needs to be protected, so rivers always have a fair share of their own water. This demands reform of the 'Environmental Water Reserve' in Victoria's Water Act.
While this is a much bigger scope than the Sustainable Water Strategy alone - it won't happen without laying out ambitious priorities in the Sustainable Water Strategy now.
