For some time now the King Rocks dam located on King Rocks Road 30km north east of Hyden has been leaking particularly when the weather warms up. The dam is listed as one of the Strategic Emergency Water Supplies in the Shire of Kondinin and is vested with the Department of Water. Water from the Rock dam is piped to near-by storage tanks for easy access for local farmers.
The Departments Rural Water Program contracted GHD Consultancy to investigate the cause of the leaking and determine the repair and management options available. Core samples were taken along the face of the wall and analysis undertaken to determine the condition, strength and density of the concrete. It was found that the concrete was in good condition considering the age of the structure. The leaking however is caused by movement when the wall heats up and cools down. This movement known as thermal expansion is generating excessive forces on the wing walls causing them to rotate at their bases and has caused the joints between the concrete layers to open. The upper layer of the wall has also lifted leaving an opening at the top of the wall.
Investigations highlighted that remedial works would need to address issues including the thermal movement, entrance of water into the lift joints, overall stabilisation of the wall and reconstructing the top portion of the wall. Cost estimates have been proposed for several repair options and range between $500,000 to $800,000.
Because of the high costs, the Department of Water need to consider whether it is practical to carry out the remedial works and justify the expenditure. They are therefore seeking the opinion of local farmers and community regarding the number of farmers reliant on King Rocks as an off farm emergency water supply. The Department is also open to suggestions of any other alternative cost effective emergency water supply options.
Please contact Alan George at the Shire of Kondinin on 9889 1006, email him at firstname.lastname@example.org or mail your thoughts and ideas to PO Box 7 Kondinin WA 6367.
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