Wednesday 20 September 2017
Hansard of the Legislative Council
Cataract Gorge, Launceston - Proper Water Flow
Mr FINCH question to ACTING LEADER of the GOVERNMENT in the LEGISLATIVE COUNCIL, Mrs HISCUTT
- (1) Is the Government aware that what remains from the flow of the South Esk River down Cataract Gorge flows through a single concrete pipe for most of the year?
- In answering my earlier questions reference was made to the intended objectives of the Cataract Gorge amenity. Who set those objectives and does the Government agree with them?
- Given that Tasmanians own Hydro Tasmania, has the Government considered compelling it to give Launceston back a proper water flow in Cataract Gorge?
- Can the Government disclose why Hydro is apparently resisting the idea of power turbines at the Trevallyn Dam wall and diverting additional water down the gorge to operate the Duck Reach Power Station?
Madam Acting President, I thank the member for Rosevears for his questions. The answers are:
- There are 2.5 cubic metres per second - known as cumecs - released through Cataract Gorge for most of the year. In addition, Hydro Tasmania has just committed to two kayaking releases each year. Trevallyn Dam also goes on spill when there are high inflows from the catchment. Hydro Tasmania voluntarily releases a nominal 2.5 cumecs flow down Cataract Gorge compared to the legal requirement of 0.425 cumecs.
Significant work has gone into the flow regime over the last 15 years. The flow was increased in 2003 to 1.5 cumecs as part of Hydro Tasmania's South Esk Great Lake Water Management Review . In 2011 the flow increased to 2.5 cumecs after an extensive review conducted from 2009 to 2011.
- Hydro Tasmania sought stakeholder views and reviewed scientific information in 2009‑10 as part of a review of the flow through Cataract Gorge. A stakeholder workshop and public meeting facilitated by Launceston City Council were held. The key objective for the flow that arose from the consultation process was the protection of flora and forna, visual amenity and the maintenance of recreational water quality in Cataract Gorge. A flow of 2.5 cumecs was determined to be the appropriate balance between social, economic and environmental considerations to achieve those objectives.
- The Government agrees that 2.5 cumecs is an appropriate balance to maintain efficient use of the water resource for electricity generation and provide suitable visual amenity and environmental condition in Cataract Gorge.
- As part of the review of the Cataract Gorge flow, Hydro Tasmania assessed the feasibility of electricity generation at Duck Reach using the 2.5 cumecs release. It was determined this proposal was not financially feasible for Hydro Tasmania to pursue. However, there is an opportunity for other proponents to pursue the Duck Reach development using the 2.5 cumecs release.
It is not financially feasible to pursue power turbines at the Trevallyn Dam wall or divert additional water down the gorge to operate the Duck Reach Power Station. Water released from Trevallyn Dam down the South Esk for power generation at Duck Reach and at the Trevallyn Dam wall would generate half the power compared to what the same amount of water would generate at the Trevallyn Power Station. Investment in new infrastructure would increase the cost of electricity generation for less energy output. Hydro Tasmania is required to ensure the most efficient use of the water resource and infrastructure for electricity generation while protecting environmental and social values.