The QCCCE report shown compares the rainfall in the Catchments for the six
years 
2001 to 2006 with the Federation drought era from 1898 to 1903.
The Era followed a major flood in 1898. It is
interesting to compare the rainfall for both periods in both dams catchments.
They qualified their report to the extent that they do
not have the Hydrology for the Federation period and concentrated on Rainfall
comparisons. If it were present, they may well have arrived at a different
conclusion.
You may have read the "Summer V Non-Summer"
information at this button.
The items of interest are the stable relationship of the Summer months 1893 to
1960. The Summer months were around 50% of the annual totals and this was
consistent with all rainfall stations in both the Wivenhoe and Somerset Dams.
This summary of Bureau of Meteorology rainfall data
shows that that they are correct on an overall rainfall basis as the
Federation period received slightly more rainfall.
However
there are two telling points of difference.
The first is the complete reversal of the
Summer and Non-Summer rains in the Federation period.
The second is that an examination of the Federation period
shows
that the months
that were likely to create inflow were decidedly less in volume and count than the current period
2001 to 2006.
In addition, they overwhelmingly occurred in the non-summer
months in both Dams.
Various other points in this web-site confirm that the Summer
Rainfall in the 6 years 2001 to 2006 were quite normal and the balance of the
reported 23.8 percent that did not fall was in the non-summer months that provide
little inflow.
Further, there was an unrelated suggestion confronting Long
Range Forecasters and reported in the C/Mail 9/06/2007 page 5. That the Dams would
fill if this period followed the weather patterns of 1903. It bears comparison.
(C/Mail
9/06/2007 Page 5) .
In the Somerset, the four months of December 2003 to
March 2004 saw rainfall of 673mm compared to the four months in 1903 May
to August was 486mm being the period that the Federation drought
broke. ( the article said May to July. August added for
balance.)
In the 2003/04 period we saw the rise in dam levels of 10 percent in
the Wivenhoe and 27 percent in the Somerset. Hardly "drought" breaking
rainfall and certainly not acknowledged as such by any Authority.
The suggestion does not stand up.
The Wivenhoe comparison for the same periods as above is 578mm
2003/04 to 392mm in 1903.
Conclusion
The Federation drought has been raised by the Climate
Change Centre of Excellence. The hard data of the Bureau of Meteorology rainfall
stations seems to dispute their conclusions and has been presented for your own
observation. I am apparently reading the same
data as the Centre. You will see from my original review of August 2006 under the "Initial
Statistics" button that I concluded the period had received close to 80
percent of average rainfall. Their conclusion was 76.2 percent.
My understanding of Scientists engaged in research is they discipline
themselves to keep an
open mind. The Climate Change Centre of Excellence may well find that the
Federation Drought may reveal more about changing weather patterns
than the last 6 years of Rainfall.
The inclusion of this section has little to do with the
overall conclusions.
My main point of disagreement is that they are classifying the 2001 to 2006
as a drought in the Catchments. To this end they are currently in good
company.
