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This website, developed since 2007, has reached a point where,
with dams full, it may be useful to reflect on events so that the acknowledged
errors of the past may be avoided in the future. Failure to do this in the
period 1989 to 2001 following the cancellation of the Wolfdene Dam, produced a
catastrophic period 2001 to 2007. It was incorrectly blamed on a multitude of
things but the main underlying excuse was the non-existent "drought"
in the catchments, proof of which will follow.
This examination covers a wide range of topics that includes
such matters as:-
* Determination of
our water supply including high rainfall events known by SEQWater as "Uncommon
events". Mr Drury's relevant statement: " You do need large
"Uncommon events" to fill large dams. You do not fill them every
year."
* Impact of our main water supply "Uncommon events"
on Dam levels,
* The
"drought" of 2001 to 2007,
*
Cancellation of the Wolfdene Dam,
* The use
of "decile maps" distorted by statistical aberration to convince us of the existence of that drought,
* Population
increase normal and predicted. No sudden up-lift.
* The
certainty of 2001 to 2007 type period happening being overlooked with the resultant high cost and
expensive alternatives not now required,
*
Rainfall in the context of Climate
Change,
* The Traveston Dam debacle and the ignored alternatives,
* The use of
statistical aberrations by including the floods of 1890 and 1893 which
significantly and permanently affect the allocation of water between us and the
ecology. The use of this aberration, if allowed to stand, will eventually force us to use a further
three highly expensive desalination plants to compensate. (Work
in progress 05/06/10. Awaiting answers to correspondence)
INDEX
Click on subject
* "Drought" of 2001 to 2007
* Uncommon events are our main water supply
* Consequences of the miss-interpretation of the action of these
events
* Traveston Dam and alternative proposal
* You cannot take water out of the
Wivenhoe/Somerset system! (true or false?)
1. Yield of the Wivenhoe/Somerset.
2. Complications introduced by the Water
Resource (Moreton) Plan 2007 enacted in March 2007.
"Drought of 2001 to 2007"
This is sometimes known as the "Millennium
drought".
The Bureau of Meteorology
tab offers the following:
* E-mail from the Melbourne office confirming that rainfall in the
catchments for the years 2004 to 2006 was close to 80% of the
long term average
1961 to 1990.
* Summary of Bureau rainfall stations in the catchments that show the 4
summer months were within a few percent of that long term average. They receive
53% of all rainfall. The 20% deficiency was in the low-flow non-summer
months.
* The use of the "decile" map 2001 to 2006 showing "lowest
on record" when the percentage map that I had them produce for the same per
showed 80% of the long term average for the same rainfall and period.
Due to the statistical aberration that rainfall in the catchment for 6
year periods had never been lower than 80%, naturally the "decile" map
recorded 80% as "lowest on record".
Photo : E Mail from Bureau of Meteorology
The Decision Makers Tab
offers the following:-
* Promotion by them of the "Decile" map as "proof" of
drought conditions in the catchments and ignoring the "percentage"
map. There is no question that most of Queensland was drought declared at that
time.
* Six year periods of the twentieth century show that there was nothing unusual
in the 2001-2007 year period. Those to the left of centre are without a high
rainfall "Uncommon " event and those to the right of centre included a high
"Uncommon" rainfall event.
Photo: "Percentage" map that corresponds with
"drought" map.
The Federation Drought Tab offers the
following. It is supported by Rainfall 2001-06:-
* Comparison of the Federation period 1898 to 1903 with the period 2001 to 2007.
It was carried out by the QCCCE (Climate Change Centre of Excellence) on the
basis of "rainfall" as they concluded that a "hydrological
basis" could not be achieved. You will see that:-
* On the basis of "rainfall" it fails because of the lack of
concentrated rain in the "Federation" period and
* It confirmed that the rainfall in the catchments for the period 2001 to 2006
was 76.2% of the long term average.
* The IQQM model is used to explore the hydrological pre-development flows in
the Federation" period contradicting the QCCCE advice that it was not
possible. The model is enshrined in law (Water Resource (Moreton) Plan 2007).
Photo : Comparison of rainfall
What was common to both periods was the absence of
"Uncommon events" being highly concentrated rainfall as outlined
above. They both exceeded the 3.7 year average of these events.
The QCCCE is an organisation that is difficult to deal with.
No one person appears in charge and my enquires seem to end up in the Department
of Environment and Resource Management or its fore-runner Departments with
different names. That Department is also responsible for the IQQM computer model
which must, by law, calculate the hydrological pre-development flows.
The Depleted Dams Tab
Assists in drawing together the above and adds additional
information.
* Rainfall stations in the catchments that have existed for approximately 100
years are examined to view to 4 summer
months December to March and the 8
non-summer months. The percentage is 53% to the summer months.
Photo : Summer rainfall V Non-summer
* Population growth. There is no
sudden uplift that caused the dam levels to drop. Population was predictable and
was
predicted.
Photo: Population growth
Climate change can be
examined by combining rainfall in 30 year lots similar to the method used by the
Bureau of Meteorology in comparing rainfall. Both catchments are shown. The
situation appears constant.
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Uncommon Events are our main water supply
Being large scale rainfall events such as monsoons,
Cyclones and large scale rain depressions.
The Uncommon Events
Tab offers the following observations.
* Rainfall comparison of 5 rainfall stations in the catchments comparing the
recent February/March 2010 rainfall with the rainfall of the other major inflows
in the life of the Wivenhoe Dam.
* The inflows in the life of the Wivehoe now verified by the Government IQQM
computer model.
* The dam level graph of the Wivenhoe Dam highlighting the major inflows.
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Consequences of the miss-interpretation of the action of these
events
Additionally the Uncommon
Events Tab offers two main photos that point to miss-interpretation of
their actions.
*The second last photo, being the Wivenhoe Dam levels,
shows that the cancellation of the Wolfdene Dam was decided at a time when the
dams were full by the April 1988 and April
1989 Uncommon Events. This is an
admitted error that ultimately cost billions of dollars and disrupted peoples
lives.
* The same photo shows that "Summer rainfall" was inadequate by itself
from as far back as 1992. It shows how dependent were upon "uncommon
events"
* The last photo is of the frequency of "uncommon events"
compiled from flood gauges and flood information available on the Bureau Of
Meteorology Web-site. While the average of these events is 3.7 years, with most
below this average, it is a mathematical certainty that those above will extend
for several years above the 3.7 year average.
Photo : Dam levels during life of the Wivenhoe dam
This was the root cause of the depleted dams in the 2001 to
2007 period. A gap of six years was experienced. A convenient statistical
aberration was use to justify the term "drought" thus hiding from
view-
* the error of judgment by not providing for such a period and
* the understanding of what was needed to correct the
situation.
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Traveston Dam and alternative proposal
* This three stage dam was the main thrust of the answer to
"drought-proofing" South East Queensland.
* Its ultimate demise was attributed to two fish and a turtle. My understanding
from the people of the Mary Valley through their publications, was that it was much more than that and is now
of historical significance.
* Mr Ron McMah, grazier of Imbil, put an alternative to the then Deputy Premier
Anna Bligh to raise the Borumba Dam from the present 46,000ML capacity to
2,000,000ML and add a pipeline from it to the Wivenhoe/Somerset for storage as
the capacity of the Wivenhoe/Somerset was inadequate to hold the flood waters of
that system. She agreed at a public meeting at Gympie, that was the way they would proceed if it
"stacks up".
* The proposal and
the appendix to it has been lodged
with the Queensland Water Commission who called for submissions of the draft
South East Queensland Water Strategy. While the Traveston has been scrapped it
still has relevance in elimination most, if not all, of the proposed
desalination plants
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You cannot take water out of the
Wivenhoe/Somerset system! (True or false)
The approach of the Queensland Water Commission to the McMah
proposal made it doomed to failure in a very short time. The Hydrologists and
Engineers were both advised that there was no water available from the
Wivenhoe/Somerset system. They prepared their report on that basis excluding the
necessary Wivenhoe/Somerset and pipeline. The Engineers did provide a costing
for a similar size dam wall approximating a dam of 2,000,000ML which was useful.
* There are two possible reasons for that advice being :-
1. The yield of the Wivenhoe/Somerset was insufficient or
2. The Water Resource (Moreton) Plan was to be introduced to Parliament
and it became law 3 months after both the Hydrological and Engineering
assessments had been completed.
We will cover both as they are both relevant.
1. Yield of the Wivenhoe/Somerset.
* This was determined by SEQWater, the dam managers in 2001
and 2002 annual reports at 446,900ML Currently the "allocations" are
286,000ML for our use in SEQ. This leaves 160,900ML available and no requirement
for desalination plants.
* However, the QWC in their draft strategy arrived at 373,000ML. This 87,000ML
discrepancy has not been explained. 
My
question to the Department of Environment and Natural Resources was
explained as an "allocation". It clearly is not. However, they are
uncertain of maintaining even this 373,000ML yield in the face of their belief in the "Millennium
drought". They have adopted a "stochastic" approach which the
cynics in Wikipedia describe as "best guess in the circumstances".
* The McMah proposal explains that in only two short periods in the last 120
years did this condition occur and is quite easily handled in the Borumba
Appendix. This then releases 83,000ML and contravenes the statement
"You cannot take water out of the Wivenhoe/Somerset system".
* We will also see that the same method will provide a further 50,000ML
available and identified by Government engineers.
2. Complications introduced by the Water
Resource (Moreton) Plan 2007 enacted in March 2007.
* Minister Stephen Robertson made it clear to me in his
letter of the 6th August 2009 that the
principal constraint of the proposal was that 66% of all water in the Brisbane
River system had to reach the Mouth of that River.
He referred to the Technical Advisory Panel's advice.
* Our share of the water calculated by that
panel is set out in that section. The calculation is based on two things:
1. The percentage of
the pre-development flows and
2. The years used to calculate the average flow
known as the "Mean Annual Flow (MAF)".
While the 66% is accepted, the use of the calculation period
of the 111 years 1890 to 2000 appears to dissent with their own literature. It
includes the floods of 1890 and 1893 which when compared to a base of 113 years
1894 to 2006, we find that the use of that now permanent percentage based on
1890 to 2000 converts to 75% for the ecology and denies us 130,568ML annually
or the equivalent of 3 desalination plants of the Tugun size.
This is more fully discussed on Water
Share including graph of the pre-development inflows which clearly shows
the distortion created by these two floods.
Correspondence with two of the most senior professors is
ongoing. (June 2010)
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*******************************************
All comments welcome. Contact
hodgkin@powerup.com.au
Official statistics record over 32,000
separate computers have accessed this web-site with over 70% retaining it in
their "favourites". The hit counter reset itself on one revision and
the correction is beyond me. A great number of readers directly access the site
via the tabs that interest them. The counter is retained for those
interested.
February 2007. Output from the
Government IQQM computer model, covering the 111 years 1890 to 2000, has proven Mr Drury correct. In essence 300mm of
rain in the catchments in a few days is a flood and, in the right circumstances,
can fill the dams from scratch. On the other hand 3 months of 100mm a month is a
comparative
trickle. These facts can be buried in official overall rainfall statistics the
use of which in dam performance can and did throw up statistical aberrations.
records from 1841 reveal that
they occur on average every 3.7 years with most below that average. Therefore
those above can extend well above that average such as the recent period of 2001
to 2007.
