Tuesday 15 August 2017
Hansard of the Legislative Council
Special Interest Matters
Cataract Gorge, Launceston
Mr FINCH (Rosevears) - The seemingly eternal argument over the volume of water that should flow through Launceston's Cataract Gorge has been going on for far too long. It is time for some progress towards a satisfactory arrangement, but that does not seem to be happening.
It all started when what was then the Hydro-Electric Commission built Trevallyn Dam on the South Esk River in the 1950s and diverted water from the gorge to the Trevallyn Power Station at Riverside, in my electorate of Rosevears, and then let it flow sideways into the Tamar through the Riverside Tailrace.
This certainly put all the water back into the Tamar, but at the wrong angle to flush out the silt which had been going into it for time immemorial. It has long been argued that Hydro should allow more water to flow down the gorge. Before Hydro was given control of dams and rivers, the flow through Cataract Gorge was between 20 and 100 cubic metres per second, and most of the time, the median flow was 50.
In 1955 the gorge flow was reduced to less than half a cubic metre per second, and that was a brutal cut. This was increased slightly to the present 2.5 cubic metres in 2003.
The former HEC's takeover of water had a disproportionally harsh impact on Launceston. Unlike in every other region, there was a serious environmental and economic price to be paid, without any compensation or offset. A long-time advocate for the Tamar, who would be well known to some members in this Chamber, Jim Collier - and certainly those who read the letters to the editor would know that name; he is a warrior for the Tamar -
Mr Dean - Very passionate.
Mr FINCH - He says the Tamar's upper reaches, particularly in the Yacht Basin at the entrance to the gorge looks nothing more than a festering sewer at low tide. He is correct. We can go down there and see this for ourselves. You might remember, member for Windermere, when we had the select committee inquiry I chaired some years ago, that the evidence that stood out for me was from Les Dick. The member will remember he talked about the way he removed the silt from the Tamar. He battered it from the sides down towards the centre to make sure that aesthetically we had that wonderful appearance of water in the Yacht Basin. We missed out on that beautiful flow that should come down through the gorge, aesthetically pleasing as it was, and of great appeal to tourists. It is interesting to note the Cataract Gorge area in Launceston was the secondmost visited and wanted‑to‑see attraction for tourists. It would be down to the sixth or seventh in Tasmania. There has been a price paid.
The state Government recently established the Tamar Estuary Management Taskforce to make recommendations on the health of the Tamar. Unfortunately, at its first meeting when the question of water flow was raised, cost came into the argument. While one of the taskforce's early jobs is to try to address the problem of raw sewage flowing into the river after heavy rain, TasWater is not represented. That aside, the water flow down the gorge is crucial to the health of the upper Tamar.
What can be done to increase the flow? Recent history has shown that Hydro will not help willingly because that would mean reducing power generation and thus income, its bottom line. What if there were a positive economic argument? The Launceston City Council wants a tenderer to develop the Duck Reach Power Station and its historic site in the gorge. One potential tenderer, Tamar Hydro
, has carefully looked at the numbers to see what is possible. Its project would require the continuous release of 8 cubic metres a second from the Trevallyn Dam to a power station at the dam wall. This water will then be released down the old river course where 6 cubic metres a second would then be diverted to the old Duck Reach tunnel. It is still there. It is still in working condition. It could be used for power generation from a new plant at the refurbished Duck Reach Power Station. Eight cubic metres a second of water instead of the present 2.5 cubic metres a second would flow down Cataract Gorge, cleaning the river and the estuary. With the raking taking place by the Launceston Flood Authority, we can see there is some success, but they need the flow of water coming down the gorge. This seems to me to be a win-win situation, and we have a state election coming up.