Environment
Degradation of the Gorge
Hydro Tasmania’s Cataract Gorge environmental flow review
I am aware many members of the community share mutual concerns for the Cataract Gorge and Tamar River,
As part of my concerns I am, in good faith, participating in Hydro Tasmania’s Cataract Gorge Environment Flow Review.
As a ‘stakeholder’ in that review I recently received an update from Hydro Tasmania relating to the Review’s progress.
I have attached that update and invite you to have a read through noting and taking into account my following comments:
1. TRIAL FLOW RELEASES; here Hydro say the trial flow released from Trevallyn Dam “…were chosen as they are considered to be the most likely potential flow options from an environmental, social and economic perspective.” Hydro then go on to say: “The 2.5 and 3.0 cumecs were chosen as the stakeholder workshop identified most support for base flows in the order of 2.5 cumecs.”
Now I attended the workshop and I don’t recall the most support for an increased flow being in the 2.5 cumecs range.
I certainly do remember discussion ranging anywhere between 5 and 10 cumecs, I did however get the distinct impression at the workshop that the Hydro would prefer a much lower figure and suspect that they are pushing that as their much preferred flow rate!
IS THE WOOL BEING PULLED OVER OUR EYES, IS THIS REALLY JUST THE HYDRO GOING THROUGH THE MOTIONS WITH THE REQUIRED FLOW REVIEW WITH THE OUTCOME ALREADY DECIDED?
You may remember I wrote an earlier missive expressing just those fears some time ago, this update has simply confirmed those fears; what do you think?
2. THREATENED PLANT SPECIES: Here the update states: “…with six species (including one recently considered to be extinct) located between the 1.5 cumecs flow level and the 3 cumecs flow level. An increase in flow would potentially have a negative impact on these six species.”
Now in relation to this I ask:
HOW DID THESE SIX SPECIES MANAGE TO SURVIVE PRE TREVALLYN DAM (1955) WHEN THE AVERAGE FLOWS WERE CERTAINLY MUCH HIGHER THAN 3 CUMECS?
I will be asking this of Hydro in my response to their update but in the meantime WHAT DO ‘YOU’ THINK?
3. MACRO INVERTEBRATES:
NO MENTION is made of the effects an increased flow would have on macro invertebrates, we were advised in a presentation given on behalf of Dr Peter Davies at the workshop, and as shown in the final workshop report, also attached, and received from Hydro (‘Aquatic fauna of Cataract Gorge’ PRESENTATIONS: C2, P30, 33, 34) that only 42 per cent of macro invertebrates were observed of what could have been expected in one section of the Gorge, in other words they have diminished by as much as 58 per cent!
Now this is serious stuff and, in my opinion, is certainly a gauge on just how bad environmental degradation in the Gorge is, yet this important report appears to have been quietly forgotten; ‘swept under the carpet’ as it were!
I have ‘very’ credible information from a ‘very’ credible scientific source that low Gorge flows are mainly responsible for this significant reduction among macro invertebrates so once again …over to you!
4. FINALLY can I remind you that in April 2008 Hydro Tasmania increased the flow through the Cataract Gorge to 6 cumecs for just a few hours to flush out the appallingly high levels of bacteria in the Tamar Basin, these levels were so much above recreational guidelines organisers of the impending state school sailing championships about to be held in the Basin felt they would have to cancel the event.
The ‘flush’ was successful and the championships went ahead.
Remember that flush was 6, yes, 6 cumecs, twice the highest flow rate the Hydro even appear to be thinking about so even if they do increase the flow rate to that 3 cumecs, believe me, it will be a complete waste!
I will be raising my concerns in my response to Hydro’s update but my voice is just one and without your help nothing more than a voice in the wilderness, IF we all express similar concerns maybe together we can achieve something!
In closing I would like to say THANK YOU so much for having stuck with me right through to this stage, I sincerely appreciate it and look forward to receiving a response from you.
Before I sign off completely though I would like to point out that Hydro Tasmania are required to hold 5 yearly reviews on Gorge flows but it seems to me this one is taking so long it will be time to start the next one before this one is even completed or …is that the idea!?
IF you would like to do something about this please write, or email, your concerns the new CEO of Hydro Tasmania:
Chief Executive Officer,
Roy Adair
Hydro Tasmania,
GPO Box 355,
HOBART 7001
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