Enernet Global and Exeter-based Tamar Hydro are seeking to develop the Bronte-Brady Mini-Hydro to generate clean renewable energy from the flow of water from Bronte Lagoon through Woodward’s Canal to Brady’s Lake. The 5.4 MW mini-hydro powerplant would take advantage of the existing water flows and infrastructure to deliver a low-impact development.
The Bronte-Brady Mini-Hydro project is located in the Tasmanian highlands on the banks of Brady's Lake adjacent to an existing water release structure supplying water from Bronte Lagoon to Brady's Lake via Woodward’s Canal. The water continues onward into the Derwent hydropower scheme. The location is indicated in the diagram below.
The project will be located near the Brady’s Lake whitewater course and trout spawning channel. Water flows in Woodward’s Canal will be reduced when the mini-hydro is operating, however Enernet’s Project will operate consistent with other stakeholder requirements for water, including:
1. Hydro Tasmania – operational water transport;
2. Inland Fisheries Service – water levels will be maintained as per the Memorandum of Understanding between Hydro Tasmania and the Inland Fisheries Service; and,
3. Whitewater events – water for scheduled whitewater events will take priority.
The mini-hydro plant itself will be located on the shore of Brady’s Lake. The water for the mini-hydro will be supplied through a new intake structure and underground pipeline. The pipeline will cross under the Lyell Highway to an underground penstock that feeds into the turbine house located on the edge of the lake.
The turbine house will hold the two or more Kaplan turbines and generators. The tailwater will be discharged into Brady’s Lake through a concrete lined tail race. Scour of the lakebed will be prevented through the placement of rock.
The project will be connected to TasNetworks’ 22kV distribution feeder adjacent the site via an overhead power line. The access road to the site will be up-graded for construction and on-going maintenance use.
At the end of the project 40+ year operational life it will be decommissioned. This will involve removal of the key infrastructure of the mini-hydro power station and reinstatement of the area.
Enernet will invest approximately $13m to construct the Bronte-Brady Mini-Hydro with Exeter-based Tamar Hydro supporting local engineering, manufacturing and construction jobs. The operation of the mini-hydro will support approximately 2 ongoing jobs in Tasmania.
The construction and operation of the project will have limited impacts on the environment. Enernet is working with the community and stakeholders to identify and minimise these impacts.
• Water levels and draw-down rates in Bronte Lagoon will be managed within the terms of the MOU between Hydro Tasmania and the Inland Fisheries Service;
• Access to the whitewater course and lake shore will be maintained;
• Flows in the whitewater course during spawning will be moderated to better protect eggs and fry;
• Redfin perch will be excluded from entering Bronte Lagoon via the mini-hydro project;
• Lakebed scour and associated turbidity in Brady’s Lake will be prevented through the tailrace design and construction;
Enernet has commenced investigations and planning to achieve development approval and construct the mini-hydro. The key project milestone dates are: