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Irrewillipe Road Retarding Basin Functional Design

The functional design for the upgrade of Irrewillipe Road Retarding Basin has been completed.

Under the design the upgrade would ensure:

  • Peak flows are managed to help prevent flooding in a manner that makes provision for growth and associated increased runoff in the future.
  • An ability to utilise the storage as a stormwater harvesting and treatment system for reuse within the local area.
  • Extensive upgrade of the surrounding landscape to enhance the recreation and amenity value of the asset

The upgrade is an example of Integrated Water Management, which is an approach that seeks to retain stormwater in the landscape, reuse it where possible and provide a runoff pattern to waterways that better resembles more natural condition.

While this is a very valuable project that would have multiple benefits for the local community and provide a model of Integrated Water Management that could be used to allow more development on the western side of Colac as envisioned in the Colac 2050 plan, the upgrade will be expensive.

It will cost approximately $2.8M. Council matched funding from the State Government and Barwon Water to help develop the functional design and will now work with them to try and secure funding for construction. Further updates will be provided on when construction will commence if and when funding is secured.

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