Sunwater: How spillway work has impacted risk of dam failure
Sunwater has outlined how much it projects the risk of Paradise Dam failing has changed since lowering the spillway.
While the Essential Works at the dam are ongoing, the spillway has been reduced and a 600mm concrete crest has been added with passive steel anchors installed through the dam's roller compacted concrete layers.
According to Sunwater the Essential Works are a short-term risk reduction measure while a longer-term dam remediation plan is confirmed and will reduce pressure on the dam wall in a significant flood event.
"With the completion of work on the dam spillway, the risk of dam failure has been reduced to a 1 in 5000-year event," a Sunwater statement read.
"Prior to the start of the essential works, the dam failure risk was 1 in 200-year event, such as the community experienced in 2013.
"The Paradise Dam Emergency Action Plan will be amended in consultation with the local disaster management groups."
A Sunwater spokesperson told the NewsMail further planned ancillary works will continue throughout 2021.
"These planned activities include quality assurance work, construction of a new fishway and concreting downstream of the dam to provide interim protection against scour.
"They are expected to be completed by late 2021, weather dependant.
The spokesperson said the total budget for the essential works was $100m.
Sunwater thanked the Bundaberg community for its patience throughout the process.
"Sunwater understands the importance of water security certainty to the Bundaberg region and is doing all it can to ensure there is as much water available as possible for irrigators and the community," Sunwater's statement read.
"No final decision about the height of the dam has been made.
"An options report and recommendation will be provided to the Queensland Government, which is expected to make a decision about the long-term future of Paradise Dam by the end of 2021."
The NewsMail understands roller compacted concrete testing, anchor trials, geotechnical, hydrology and water demand studies are underway and set to inform the assessment of the options for Paradise Dam.
"Sunwater is gathering as much information as possible to confidently inform the report and recommendation," the statement outlines.
"We need to ensure we get the best outcome for the future of the dam and the community and customers.
"The decision can't be rushed."