Tasmanian waterways: a policy failure on a grand scale

A new scientific survey details severe and chronic failure to monitor the health of our waterways.

A group of Tasmanian scientists – “professional” would aptly describe them except that this is a voluntary group – has begun filling some glaring holes in Tasmanian environmental reporting.

“The Tasmanian Freshwater Project” is one of a number of current environmental investigations by the Tasmanian Independent Science Council. Its first part, looking at the condition of our island’s waterways, is the work of Christine Coughanowr.

On the matter of Tasmanian water resources, quietly-spoken Coughanowr is not a person anyone should ignore. A scientist with more than three decades in water quality management, she helped set up the Derwent Estuary Program in 1999 and led it for 19 years. She has contributed to numerous inquiries into waterways, coastal waters and aquaculture.

Politicians of all colours like to promote the idea that Tasmania is uniquely placed among Australian states to capitalise on an abundant freshwater supply. The Liberals are especially gung-ho, currently proposing a vast increase in irrigation to raise farm-gate production six times over by 2050.

Not only that, but they are working with salmon farmers to double the gross value of the sector to $2 billion by 2030. Plentiful freshwater is essential in the hatching, early growth and lifelong health of farmed salmon. Planned expansion of mining, forestry, tourism and recreation sectors will draw further on our island’s finite supply of water.

Disconcertingly, we know very little about how much water is currently distributed to various users, because most water used in Tasmania is unmetred. We do know that even before the six-fold Agrivision-2050 plan, irrigation is allocated over half of our state’s resource, but we have no real idea how much it actually gets.

We all know that as individual householders we pay TasWater for every drop of water that comes out our taps, but few are aware that those impositions don’t apply to some really big users, whose annual bill for water they take from rivers can be as little as $400 a year.

Coughanowr asks, could the government’s water plans possibly be viable? Or after chronic neglect of programs to monitor the quantity and quality of water resources, are our leaders asleep at the wheel? Her data indicate only one possible answer, and it’s not the first one.

A program to keep tabs on the amount of environmental flow in a river –the flow needed to maintain water quality, prevent silting and sustain habitats – was abandoned in 2014. Since then this work is done only on demand. Some results and recommendations are made available publicly, but more often they are withheld.

Coughanowr cites Tasmanian Irrigation’s plan to double water extracted from the Derwent to send to the dry south-east. The most recently-published Derwent eflow study, released in 2002, concluded that no more water should be taken from the river in summer, yet with no further published study the proposal is proceeding. We’ll have our dry-land lettuces, but for how long?

Flying in the face of the claim about abundant Tasmanian water is a little-reported incident in the summer before last, when the South Esk, one of Tasmania’s largest rivers, stopped flowing at Perth. Its flow remained very low for several weeks. A suggested cause was over-extraction for irrigation, but there has been no formal investigation.

Hand in hand with questions about abundance and flow are a lot more questions about water quality and the health of river systems. Tasmania has a long history of mining pollution, especially on the West Coast, but now we are seeing increasing pollution from farming run-off, including severe dairy farm pollution in far northwestern rivers.

Summer and early autumn sampling below large flow-through fish farms in the Derwent system reveals nutrient levels over 50 times higher than levels upstream of the farms. Growing taste and odour issues in Hobart drinking water pushed the government to put $220 million of public money into a new fast-tracked water treatment plant at Bryn Estyn.

Knowing next to nothing about the true state of our island’s freshwater resources, political and bureaucratic leaders continue to promise a bountiful future enabled by abundant, potable freshwater. That is the height of folly, and policy failure on a grand scale.

Full disclosure: Coughanowr’s review was partially supported by a grant from the Hobart-based Detached Cultural Organisation. As a member of TISC I had access to an advance copy of the review but had no part in its research and writing.

Christine Coughanowr will discuss her review of the state of Tasmanian freshwater at the Fern Tree Tavern tomorrow from 6 pm. Booking on Facebook Events.

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