In 2012-13, we commissioned an independent review of our 26 referable dams, which found improvements are needed at a number of our dams to meet the Queensland dam safety guidelines into the future.
We have prioritised a program of dam upgrades in a staged approach to give us time to scope, design and plan, while maintaining public safety, security of water supply and delivering best value for money.
Ewen Maddock Dam is one of a number of dams in South East Queensland scheduled to be upgraded as part of our regular ongoing maintenance.
Ewen Maddock Dam was built in two stages in 1976 and 1983 across Addlington Creek, a tributary of the Mooloolah River. Located on the Sunshine Coast, Ewen Maddock Dam is part of the SEQ Water Grid.
In 2012, stage one upgrades at the dam involved the installation of pressure relief wells along the left abutment of the dam wall, and construction of a 1.5 metre weighting berm on the downstream toe area.
Ewen Maddock Dam Safety Upgrade
The stage two upgrade work is set to begin from August 2019 and will include strengthening the existing embankment and raising the dam wall to increase its floodwater capacity. Work is expected to take up to 18 months, subject to weather conditions and other unexpected delays.
Currently, the water level within the lake is at about 90 per cent of the Full Supply Level. During the upgrade we will need to lower the water level of the lake to about 50 per cent of the Full Supply Level. Lowering water levels is an industry accepted practice to manage dam safety and bank stability during upgrades. The lake will return to the current Full Supply Level following project completion and adequate rainfall.
For the safety of the public, all on-water recreation, access to the designated swimming area, access to the multi-use trails from Maddock Park, and the recreational use of Maddock Park will be closed for the duration of the upgrade work. Access to the multi-use trails from alternate locations will be maintained where possible.
The upgrade work will not impact on water supply security which will be maintained by the SEQ Water Grid.
You can stay up-to-date with the progress of the Ewen Maddock Dam Safety Upgrade by subscribing to our e-updates below.
We apologise for any inconvenience this work may cause, and we thank you for your patience during this essential safety upgrade.
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