The Eastern Sub-Station
Western Power propose to build a sub-station in the Perth hills in the Shire of Kalamunda/Mundaring area. Initially they will develop a 4 hectare site to contain a switchyard, however this has the potential to expand to a total of 20 hectares including another switchyard as well as transformers. Western Power say they may not develop it further, however they are currently seeking a 20 hectare site in the Perth hills suggesting that the addition of transformers and a bigger switchyard is a very real possibility.
The Study Area
Western Power identified a wide area which they deem appropriate for the sub-station to be established. Areas which are in this Study Area include: Carmel, Bickley Valley, Hackett's Gully, Paulls Valley, Pickering Brook and Piesse Brook.
You can download a detailed map of the Study Area here from the Western Power website:
http://www.wpcorp.com.au/documents/currentProjects/easternTerminal/All%20Constraints.pdf
The Study Area encompasses vast areas of State Forest and National Park and almost all of the Study Area is a Priority 1 or Priority 2 water catchment area.
Western Power has informed us that the Shire of Kalamunda has refused to allow the sub-station to be built in National Park, although building in State Forest is seemingly permitted.
The Water Authority has stated to Western Power that they can not build the sub-station in the P1, P2 or P3 water catchment areas. This would seem that almost the entire Study Area is precluded from development – however Western Power will continue to push for a site within this area because of previous rulings allowing sub-stations with transformers to be built in P1 areas.
Why Here?
The eastern sub-station would be linked to 2 existing lines that run through this area. On the Study Area map provided by Western Power, this station would need to link to the dark blue line and the yellow line. The sub-station would need to be built close to these lines to ensure that further corridors of wires are not needed to be erected to connect the system. However, as you can see on the map, these lines intercept and follow a similar path North-West for quite a distance out of the boundary of the Study Area. Western Power informed us the cost of the project would be much higher if they were to build a sub-station out of the Study Area – the decision is purely economical and the environmental impact is not a factor in their decision.
Water Catchment
Almost the entire Study Area is a water catchment area – most of which is classified as Priority 1 or Priority 2. Especially now in times of lower rainfall and increasing population, water is seen as a precious resource and ensuring future water sources for Perth and indeed the state of WA has been a challenging and important task the government is undertaking.
Our water catchment areas must be protected from these types of developments – especially from a sub-station development which has the potential to contain toxic substances. Yes, Western Power will have measures in place to attempt to stop leakage from seeping into the ground, and therefore into our drinking water, however no measures are completely assured to work. If a leak was to occur, this would not only contaminate the drinking water of Kalgoorlie-Boulder but also the drinking water of local residents who are not on scheme water and rely on their bore water for their household use.
Die Back
Die back, Phytophthora cinnamomi, is a fungal disease that kills 40% of plant species world wide. It attacks the roots starving plants and trees of water causing death. There is currently no way of killing this fungus and the only management strategy is to regularly inject each individual infected tree and spray infected areas with phosphonate – the trees, plants and surrounding soil remain infected with die back, the phosphonate simply boosts the plant’s natural defences.
Die back is a very big problem in the Perth hills and indeed it is now spreading to parks and local gardens in Perth itself. A significant cause of the spread of dieback is human activity and restricting such activity is imperative to halt the spread of this devastating fungus. Construction, heavy machinery and clearing of forests can contribute significantly to the spread – all of which is necessary when building this sub-station. Measures, such as spraying down machinery, can be used to assist in stopping the spread from one site to another, however all it takes is a pinch of infected soil to be transferred for the infection to spread.
Other options?
Western power identified 8 transmission solutions to assist in boosting power to Perth metropolitan area, these are:
1. Establish a 330 kV transmission line from Landwehr Terminal to South East Terminal.
2. Establish South East Terminal and reinforce Landwehr Terminal.
3. Establish South East Terminal and provide additional reactive support at Guildford Terminal.
4. Installation of SVC at Northern Terminal to defer option 2.
5. Series compensation of the 330 kV bulk transmission network.
6. Establish a 330 kV transmission line from Collie to Easter n Terminal.
7. Installation of SVC at Northern Terminal to defer option 6.
8. Establish a 500 kV transmission link to the metropolitan area.
Western Power identified option 6, the building of an Eastern sub-station as “the best economic solution”. The environmental impact of this or any other project was not taken into consideration when deciding on the solution. In fact, it is only once Western Power chose this particular option and then went onto identify a Study Area that an environmental consulting firm was brought in to evaluate the impact this may have on the “Study Area”.
Should it not be that the environmental consulting firm (Environmental Resources Management (ERM)) help choose an appropriate Study Area in conjunction with Western Power, as they have the expertise in evaluating the impact of such a development? Instead, Western Power have directed ERM to the wider study area they must look within, and ERM must then identify an area within that where the sub-station should be built.
The Impact
The hills are a 30 minute drive from Perth city and increasingly becoming an area of tourism. With rolling hills, beautiful forest, bush walking, wineries, gourmet food, restaurants and accommodation the Perth hills have much to offer and is becoming a holiday destination for the people of Perth as this area offers all the benefits of the South West region without the long drive.
With so little forest left and with so little development in this area it is imperative that this area be protected and valued for what it is and what it can offer – not only for those that live in the area but for those that come to appreciate the Perth hills.
