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.
Cooloolabin Dam upgrade
The assessment at Cooloolabin Dam identified a significant upgrade (about $28 million) would be required to meet the relevant dam safety guidelines. 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 the best value for money.
As a short term solution, the water level at the dam was lowered in 2013. In late 2015, a slot was cut in the centre of the spillway to maintain this lower water level and delay the need for a significant upgrade.
Lowering water levels is an industry-accepted practice to best manage the safety of dams either temporarily or in the long term. Lowering the water level in a dam reduces water pressure and loads on the dam wall, and can also create temporary storage to increase its capacity to mitigate floods.
We will start work to upgrade Cooloolabin Dam in 2017-18, as part of Seqwater’s Dam Improvement Program.
The costs and benefits of a number of upgrade options were assessed, following our initial investigations in 2013, and a preferred option has been selected to meet the Queensland Dam Safety Management Guidelines.
The upgrade will involve constructing a filter buttress to reinforce the embankments on either side of the dam’s spillway and the lower part of the largest saddle dam.
We have released an open market tender to select an experienced contractor for the upgrade. Construction is expected to start in October 2017, subject to approvals.
Until October, our focus will be on preparing for construction and putting plans in place to minimise impacts to the surrounding environment and local community.
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