Are new dams an answer to the water crisis?

The Burrendong Dam empties at speed because water sharing plans allow it to.

The New South Wales and federal governments say that building new dams and raising the walls of others are the answer to the state’s water crisis. But are they? Water experts advise that such large infrastructure projects do not necessarily save water, but instead divert water to irrigation, potentially killing rivers and leaving communities more vulnerable to water insecurity.

Ninety NSW towns faced the prospect of running out of water last summer. Farmers in the nation’s food bowl (the Murray-Darling Basin) faced ruin as water prices soared. As the water market prioritises supply to those able to pay the price, in the Upper Darling River nearly 80% in the northern catchment ended up in the hands of two corporate irrigators.

At the same time, the Baaka (Darling River) ceased to flow, the Menindee Lakes became a dustbowl and millions of fish rotted. While the fish kills received significant attention, little was given to the people who rely on river flows for their survival.

Such is the enormity of the inland water crisis that whole communities were left without safe drinking water. Conditions in some Aboriginal communities are now so bad that senior researchers from the Jumbunna Indigenous House of Learning, Ruth McCausland and Alison Vivian, say that life expectancy in Wilcannia on the Baaka is as low as 37 years for men and 42 for women.

The federal and NSW governments have decided to allocate $1 billion to build more dams and raise storage capacity at Wyangala Dam in central west NSW and Dungowan Dam near Tamworth. They also want new dams built in drought-stricken northern NSW.

But will more dams turn around the Murray-Darling Basin water crisis? A brief look at the water management failures would suggest not. 

Enough dams already

As The Australia Institute’s Maryanne Slattery put it: “It may seem obvious, but building new dams doesn’t make it rain. Even if it does rain, we already have plenty of empty dams where the water can go."

Mel Gray of Healthy Rivers Dubbo told Green Left that Burrendong Dam, one of the biggest in NSW, empties at speed “because the rules in the water sharing plan allow it to — encourage it too," despite its enormous capacity of 1188 billion litres. The Burrendong dam supplies 70% of Dubbo’s water needs (8 billion litres a year) and has nearly bottomed out three times. “In the summer of 2019/20 plans were in place to suck the dead water from the very bottom of the dam," Gray said.

“The river below [the town of] Warren [north-west of Dubbo] was allowed to dry up and that was followed by the massive deaths of native fish, turtle, mussels and other wildlife. People below Warren were left with no access to water from the river for their domestic and stock needs.”

Healthy Rivers Dubbo is also opposed to plans for a new weir at Gin Gin on the Macquarie River, saying it will result in a 25 billion litres a year loss of water for the environment. 

The NSW government knows that the Macquarie is over allocated, Gray said. “It is evident from NSW’s 2014 State Infrustructure Strategy that while Burrendong is one of the biggest dams in state, the irrigation industry has developed to a size where the natural capacity of the river has been exceeded. There is simply too much water being sucked out.

“The most effective, common sense way to address water security issues in the Macquarie Valley is to look at the glaring problems with the rules in the water sharing plan, not to pour many tens of millions of public dollars into a monstrous structure that will only benefit a privileged few.” 

The over allocation of water from rivers in NSW is a key concern for scientists, who have just published their views in the Journal of Hydrology. Lead author Celine Steinfeld, a member of the Wentworth Group of Concerned Scientists, said: “It was clear that water in the Macquarie had been over allocated”. Much of the problem is created by a “credit rule” which guarantees water allocations of projected inflows that are highly variable and declining rapidly. “The credit rule is essentially allocating clouds — water that hasn’t even fallen in the catchment yet,” Steinfeld told the Sydney Morning Herald on June 6. These problems are repeated across the state.

International studies confirm that the supply-demand cycle, where increasing water supply leads to higher water demand, is a problem. “Over-reliance on reservoirs increases the potential damage caused by drought and water shortage,” said Professor Giuliano Di Baldassarre of Uppsala University in Sweden in 2018.

Expensive

Dams are also expensive. The upgrade of Dungowan Dam near Tamworth involves raising its capacity from 6 to 22 gigalitres. The additional 16 gigalitres is estimated to cost $480 million, or $30 million per gigalitre. To put that in perspective, the Department of Agriculture and Water Resources budgets $3 million per gigalitre for its current water recovery, according to a cost analysis conducted by The Australia Institute.

More often than not, dams in regional Australia do not provide value for money. Over the past 30 years, only private dams, each several square kilometres in size and financed by the government’s water efficiency grants schemes, have been built. Politicians do not like to talk much about these dams, given that they do not help drought-stricken towns, struggling rivers and down-stream water users. Any such state-funded infrastructure project would require higher environmental and economic assessment benchmarks, as well as public consultation and scrutiny.

The National Water Initiative states that all water infrastructure proposals must “continue to be assessed as economically viable and ecologically sustainable prior to the investment occurring”. But the NSW government is determined to circumvent lengthy environmental approvals, land purchases and business cases to begin the construction of these new public dams by 2021.

Altering rivers

The World Commission on Dams (WCD) argues that: “Dams fundamentally alter rivers and the use of a natural resource, frequently entailing a reallocation of benefits from local riparian users to new groups of beneficiaries at a regional or national level.

“In too many cases an unacceptable and often unnecessary price has been paid … especially in social and environmental terms, by people displaced, by communities downstream, by taxpayers and by the natural environment.”

Among the environmental concerns associated with large water storage is the damage they cause to water quality within the storage and downstream. These include raised salinity and deoxygenation, which leads to toxic blue green algae blooms which impact on the human health, livestock and wildlife.

Significant changes to floodplains and river flows have also badly affected aquatic life, habitat and wetlands. Director of the Centre for Ecosystem Science at the University of NSW Professor Richard Kingsford has raised the alarm over the viability of the internationally significant Macquarie Marshes where 3000 hectares of reed beds burned in the 2019 bushfires. The loss and degradation have caused a significant drop in the population of native water-dependent species.

The case for building new dams runs counter to the terms of the Murray-Darling Basin Plan. If more water is diverted, for example via a new dam, then an equivalent amount of water needs to be taken out of irrigation somewhere else. If that does not happen, the government is reneging on the Basin Plan, opening itself to potential legal challenges by affected water users.

Inspector General of the Murray-Darling Basin Plan Mick Keelty, in his recent report on the basin, highlighted a 50% decline in inflows in the past 20 years, likely to be due to climate change. 

The ARC Centre of Excellence for Climate Extremes released a report in May confirming that there will be longer, more frequent and intense droughts. Meanwhile, governments have been at pains to silence or ignore public discussion of the impact of climate change, saying that natural causes are to blame for lower inflows.

“When working out how much water to sell every year, the NSW government does not take into account any rainfall and inflow data from before 2004,” Gray said. “It chose to only look at last century’s rainfall patterns, when it was a lot wetter. Many communities in the Murray-Darling Basin hold fears over their future, with more frequent and extreme weather events.”

The inconvenient truth for governments is that there is no going back to pre-1950s weather conditions. Their failure to stop the corporate over-extraction of water from rivers, or to enforce national water sharing rules, combined with the lack of climate policy, means that the water crisis will intensify. Building dams is 1950’s thinking: more dams will only dig us into a deeper hole.

[Tracey Carpenter is an activist with Water for Rivers.]

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