Engineer's emails reveal Wivenhoe Dam releases too little, too late to
help Brisbane
* By Hedley Thomas
* From: The Australian
* January 21, 2011 2:13AM
* Emails became increasingly urgent
* Inquiry to examine operators acts
* Water may have been held back too long
LEAKED email communications from a Wivenhoe Dam engineering officer
underline concerns that the Brisbane River flood was mostly caused by
massive releases from the dam after it had held on to water too long
over a crucial 72 hours before the severe rainfall that hit the region
last week.
The emails, which become increasingly urgent in tone as the situation
became critical as the dam's levels rise rapidly, were provided to The
Australian by a source who said the stream of data had convinced him
the river flood of Brisbane could have been largely avoided if the
dam's operators had taken action much earlier, reported The Australian.
A commission of inquiry will examine whether the dam's operators erred
in permitting the dam's flood compartment to be severely limited for a
major rainfall event because of their strategy to let the dam's levels
rise over the weekend of January 8-9.
Start of sidebar. Skip to end of sidebar.
Related Coverage
* Fireworks off: Brisbane flood
* Dams manual made public Courier Mail, 2 hours ago
* Manual for Brisbane dams released The Daily Telegraph, 3 hours
ago
* Engineer warned of dam danger Perth Now, 18 hours ago
* Wivenhoe Dam closes floodgates - for now NEWS.com.au, 1 day ago
* Save or spill conflict for dam bosses The Australian, 2 days ago
End of sidebar. Return to start of sidebar.
According to figures from Wivenhoe's operator, SEQWater, the dam's
capacity went from 106 per cent full on the morning of Friday, January
7, to 148 per cent full on the morning of Monday, January 10, due to
the limited weekend releases. Experts have said this severely
compromised the dam's ability to store additional runoff.
By Monday morning the dam was at 100 per cent capacity for its supply
of water for urban use, holding 1,150,000 megalitres. In addition its
flood compartment, with a capacity of 1,450,000ML, was almost half full.
The dam reached about 190 per cent capacity by Tuesday, when its
operators made huge and unprecedented releases to prevent the system
from collapse.
The emails from engineering officer Graham Keegan, of SEQWater, which
operates the Queensland government-owned dam, were sent to notify
stakeholders about dam strategies, including release rates and likely
impacts. Mr Keegan, who was receiving advice from the Flood Operations
Centre at the dam, advises in an early email at 8.26pm on Saturday,
January 8, that the releases of water that night were 1250 cubic
metres per second (cumecs) and were to be kept to a "maximum of 1600"
at mid-Brisbane River.
The same email notes awareness of the worsening weather: "Forecast for
the next 4 days is for significant rainfall across SE QLD. Possible
scenarios include a reduction in release rate to accommodate potential
flooding in the Bremer River; however they also include larger
releases from Wivenhoe Dam if heavy rainfall strikes our catchments.
Releases may then extend to the week-end or later." By 8.30pm on
Sunday, Mr Keegan's email alert advises the plan is to keep releases
from the dam to 1400 cumecs "for the next 24 hours if possible".
To read more about the leaked dam emails visit The Australian.
Read more: http://www.news.com.au/breaking-news/floodrelief/engineers-emails-reveal-wivenhoe-dam-releases-too-little-too-late/story-fn7ik2te-1225992047316#ixzz1BawpYETy
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