Lake Manchester Dam Safety Upgrade
Leed increased the primary spillway capacity to cope with large floods


The 26,000 ML Lake Manchester Dam north of Ipswich is Queenland's fourth oldest dam, originally completed in 1916. It is one of a number of dams supplying water to the South East Queensland Water Grid.

The dam required an increase in primary spillway capacity to cope with potential flood events and to meet the guidelines established by the Australian National Committee on Large Dams (ANCOLD). 


The primary spillway upgrade involved:

  • construction of a 7,000 m3 reinforced concrete and shotcrete spillway including ground and rock anchors
  • 80,000 m3 of bulk earthworks at the left abutment including drilling and blasting
  • design and installation of a steel coffer dam upstream of the existing spillway
  • demolition of the existing spillway


  • The challenging terrain made access very difficult and was an important consideration when developing the drill and blast plan
  • The high temperatures required measures to lower concrete temperatures both before and after each pour
  • A special concrete mix design was developed for the higher temeratures encountered


  • The project works were successfully staged to allow the spillway to operate during the wet season
  • A drilling solution was designed to maintain the structural integrity of the existing dam during drilling and blasting works
  • The project was succesfully delivered to a high standard and with no Lost Time Injuries.

“I have been working with Leed on ANCOLD dam upgrades since 2003. Their performance has been both exceptional and without a single safety incident or accident”

Richard Rodd, Managing Director and Principal, Richard Rodd & Associates, October 2017.

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