Copeton upgrade not affected by rising dam level
20 December 2011
With the Copeton Dam water level reaching 90 percent today, State Water has reaffirmed the upgrade works will not affect normal dam operations.
Stakeholders of the dam were updated on the upgrade works last Thursday at the regular community construction liaison group meeting on site at the dam.
State Water Copeton upgrade site co-ordinator Duncan Wilson said a cofferdam had been built around the construction area to protect the works from water in the storage.
“As consistent with our other upgrades the contractors at Copeton constructed a cofferdam which is a structure to keep water away from the works and allow the water level of the dam to rise and fall as normal,” Mr Wilson said.
“The Copeton upgrade is to ensure the dam can safely pass extreme floods and the operation of the dam will not be impacted by the project during or after construction.”
A 250-metre-wide spillway is being constructed by Macmahon Contractors to allow Copeton Dam to safely pass more water to preserve the dam wall should an extreme flood occur.
“At the community liaison group meeting Macmahon reported that 440,000 cubic metres of material has been excavated from the new spillway area which is in line with their schedule.”
The bypass road which will divert traffic around construction works on the new spillway is scheduled to be operational after the December/January school holidays to ensure minimal disruption over that period.
State Water will continue to monitor the water level of the storage and if the dam is forecast to reach 100% of its capacity then State Water may make controlled releases to mitigate peaks in downstream water levels.
Copeton Dam is not surcharged above 100% capacity, except in very large flood events, so once full capacity has been reached any inflows must be released into the Gwydir River.
Floodplain landholders downstream of the dam are advised to review their own flood plans and consider their actions in preparation for Copeton Dam approaching full supply level.
For information about storage levels and river heights visit the NSW Water Information website www.waterinfo.nsw.gov.au.
Media contact: Jane Urquhart State Water (02) 6841 2087 or 0429 449 711
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