Call to reinstate Gorge to more `than a mere trickle': More power, but no more water

Launceston Examiner
Friday 18/4/2008 Page: 1

A MINI power station below Duck Reach in the South Esk River is being investigated by Hydro Tasmania. But it appears that the scheme, which if built could cost around $2 million, would not result in the release of any more water through Launceston's Cataract Gorge. Hydro corporate affairs spokesman David Jeffrey said yesterday that the company was looking at a number of ways to improve efficiency and the mini hydro scheme was one of a number of ideas.

"This is really, really, early days and we have put it on the list of things to look at over the next six months," Mr Jeffrey said. "If it was feasible we would look at it further... but at the moment it is a bright idea on the list to look at." Mr Jeffrey said the Federal Government's Mandatory Renewable Energy Target scheme could "tip the balance" in Hydro's favour to build a 1.5MW station that would provide enough power to supply 900 homes.

A similar station at Lake Parangana, in the North-West, cost Hydro $1.5 million in 2002. Mr Jeffrey said a new station would not lead to an increase in water flow through the Gorge. Hydro releases 1.5 cumec from Lake Trevallyn to "maintain environmental quality" in the Gorge. "If it were to be a goer, it would use the existing environmental flow that's put through the Gorge area. It wouldn't be increased," Mr Jeffrey said.

Since the agreement that requires Hydro to release a minimum of 1.5 cumec, the Meander Dam has become operational - putting a more consistent flow of water into the South Esk River, which flows into Lake Trevallyn. At the height of summer, the Rivers and Water Supply Commission must release 20ML a day, or 0.23 cumecs, from the Meander Dam to meet its environmental flow requirements. In April, the RWSC must release 70ML a day, which equates to 0.8 cumecs.

Because of recent rainfall, the RWSC decided to increase flows from Meander Dam to 4.5 cumecs, but Hydro has not released any of that extra water through the Gorge. However, after concerns about water quality in the upper reaches of the Tamar River, Hydro decided to increase its flows to 6 cumecs for a four-hour period today to flush-out the yacht Basin. The 4.5 cumecs from the Meander Dam added to the Hydro's environmental flow of 1.5 cumecs adds up to the 6 cumecs - which the Hydro said would be released at a value of $5000.