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| The back-up generator used during the floods at Wivenhoe Dam. |
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| A page from the Wivenhoe Dam incident log. |
WIVENHOE Dam staff were forced to use an "unreliable" 25-year-old diesel generator to operate the gates at the dam wall when power was lost during the worst of the 2011 floods crisis.
That was because Seqwater had failed to act on its engineers' recommendation to junk it months earlier. The unit remains in service, 21 months after it was identified as requiring "immediate" replacement.
Previously unseen incident logs from Wivenhoe, obtained by The Courier-Mail using Right To Information laws, captured the unfolding drama as a handful of junior staff battled crises on multiple fronts.
They showed the back-up generator at the dam wall was fired up at 9am on January 11, 2011, when all mains power was cut by floodwaters, and remained in use until power was restored 36 hours later.
It was during this period that the operators' strategy changed from protecting downstream properties to saving the dam. It was also when the massive releases were made that flooded Brisbane and Ipswich.
The logs showed staff made frequent calls to Energex asking how soon the power would be restored.
One entry reads: "Energex waiting for break in weather, will heli deploy staff." Another notes simply: "Energex doing something."
"They weren't happy with that (generator) being the only source of power at the wall," a person involved in the crisis told The Courier-Mail.
There was no mention of back-up power at the dam in the findings of the $15 million flood inquiry. The logs from the wall, which Seqwater says it handed over to the inquiry, were never discussed in hearings.
The documents showed there were also communications failures as fax lines, over which directives were received from the flood operations centre in Brisbane, were cut.
"Water ingress" affected some equipment and operators took inventories every few hours of how much fuel was left for the generator.
The diesel generator unit is the main emergency source of high-voltage power to open the dam gates and for lighting and other services at the dam. Its replacement was the top recommendation of a five-year maintenance survey of the dam led by principal dam safety engineer John Tibaldi in September 2010.
"The main issues found during the inspection relate to ensuring the ongoing reliability of the standby diesel generator," the report said.
"This unit is now over 25 years old and appears to be approaching the end of its useful working life."
Under "General recommendations" the report concluded: "Replace the Standby Diesel generator as it is no longer reliable".
The work was given a "criticality" rating of one, defined as "rectification required immediately, that is, within one month".
Seqwater said this week: "Following the (September 2010) report and ahead of the 2010-11 wet season, the standby generator was serviced as part of an ongoing maintenance program and capable of operating as required."
Seqwater said it had "begun planning the procurement" of a new generator after the 2010 report. It blamed flood repairs for holding up the work.
A new generator was now part of the 2011-12 works program, with a budget of about $280,000, it said.
"It should be noted that works identified in the 2010 report are not critical to the ongoing operation of Wivenhoe Dam," the company said.
But it said a further back-up generator had been added since the 2011 floods.
