AN OBSERVATION OF THE CONFLUENCE OF STATISTICAL ABERRATIONS, DAM RATIOS, TIMING AND UNCOMMON RAINFALL EVENTS THAT COMBINED TO PRESENT OUR DAMS AS VICTIMS OF A SEVERE DROUGHT. THIS IS NOT THE CASE. THEIR INFLUENCE ON CONCLUSIONS REACHED AND ACTIONS TAKEN.

Author : J. V. Hodgkinson F. C. A. Chartered Accountant : August 2006 to December 2009

The Underlying cause of our depleted dams had the appearance of "drought". However most people would not class 80 percent of rainfall compared with the Bureau of Meteorology long term average 1961 to 1990 as a "drought". This is the case in the catchments. Even less people would class it as a "drought" when closer examination of the rainfall shows that the inflow producing four Summer months had been quite normal with 99.7% in the Wivenhoe and 91.3% in the Somerset catchments. The 20% deficiency was in the low inflow producing eight non-summer months.

This incorrect conclusion of "drought" has clouded the real underlying cause of our depleted dams. It is the random nature of large scale rain depressions and they are our main water supply. They occur on average every 4 years and have the capacity to fill our dams in a few days. The last gap was six years 2001 to 2007 and caused a major and expensive panic. Further evidence is available in the tab DEPLETED DAMS or Click here

Dealing with those large scale events that extend beyond the 4 year average requires a very different approach than dealing with a "drought". The current water resource strategy has ignored the short history of the Wivenhoe dam.

December 2009

Transferred from the HOME page due to the cancellation of the Traveston Dam. Some of this material is still relevant

A lack of understanding of the root cause of our recently depleted dams is continuing to have an adverse effect on the decision making process. The "root cause" was disguised by a statistical aberration. It indicated that it was a "drought" when it was not. It was the temporary departure of high rainfall events in the dam catchments. The high rainfall events are random. Unlike our summer rains, their timing is not dependable.

Rainfall of 300mm in a few days is a flood that can fill the dams from scratch whereas 3 months of 100mm each month is a trickle even though it is the same measurement of rainfall. This type of random action has been occurring since rainfall records were kept. Some published rainfall measurements can disguise this natural occurrence and it is particularly relevant in dam catchments.
Photo : Courier Mail article on rainfall in the catchments 10th February 2007

The people in control of our water supply continue to grapple with the "consequences" of the cause of our depleted dams rather than deal directly with the "root cause". The following decision highlights their actions and it has the strong possibility of heavily impacting on our water supply.

A Major decision of the Government to limit our available water from the Wivenhoe/Somerset dams to 1/3 of all water through those dams, is about to be monitored and enforced.

A brief overview followed by more detailed information

Currently we have 360,000 megalitres available to us each year. It is based by the Government on rainfall over the last 120 years.

The decision by Government, and about to be enforced, is that 66% of all water through the Wivenhoe/Somerset dams must find its way to the Brisbane River mouth. The remaining 34% is for our own use.

The arithmetic of that decision is "if 34% represents our share providing 360,000ML a year that we currently have, then 100% of that water must occur each year to provide that water we already have and ensure that 66% reaches the Brisbane River mouth". The answer is 1,058,823 megalitres. (360,000ML divide by 34% X 100% = 1,058,823ML).

To get an understanding of how much water that is, the Wivenhoe dam capacity is 1,165,000 megalitres. 

So to provide for this Government decision, a volume of water almost equal to the capacity of the Wivenhoe Dam must occur each year. That is the way the Law is written.

Summer rainfall, that we have come to know so well, takes approximately 7 years to fill the dams from scratch to full, provided we do not take any water out. 

To achieve the Government objective, a very large injection from large scale rainfall events must occur. SEQWater describes them as "uncommon events". They have the capacity to fill the dams from scratch to overflow in a few days. For further description see CURIOUS DROUGHT.

The influence of these random large scale rainfall events during their absence has been misunderstood as a "drought". This is still the case observed through correspondence with the Queensland Water Commission. Six of these events appeared at regular intervals to fill and overflow the Wivenhoe Dam from its start in 1986 to February 2001 when they departed. The dams are now 75% full from 4 near-misses in the last 2 years. 
Photo : SEQWater Wivenhoe dam level chart overlaid with high rainfall events

The problem we face is that the Wivenhoe/Somerset dams are inadequate to hold such large quantities of water that occur from time to time. They must provide water, equivalent to the total capacity of the Wivenhoe dam each year irrespective of the seasonal conditions, to meet the conditions which the Government has placed on the Brisbane River.

In a much smaller way, most farmers would tell you that the capacity of their rainwater tanks and dams have to match the rainfall when it happens and be sufficient to carry them through all seasons.

That storage capacity is readily available utilising the Borumba Dam expanded to 2 million megalitres. The Government appointed engineers GHD outlined this in their report when considering all dams and Weirs in South East Queensland. That Dam would be the largest dam in Queensland and larger than the joint Wivenhoe/Somerset dams. It is 60klm over the hill in the Mary Valley.

Photo : Borumba Dam, looking down from ridge 

We will see that the use of the expanded Borumba Dam would provide much more water to South East Queensland than the Traveston proposal and much sooner.

August 2009 Update

Ministers Hinchcliffe (Planning and Infrastructure) and Robertson (Natural resources and water) have responded to a recent meeting with Minister Hinchcliffe and follow-up correspondence. Ministerial portfolios were recently split. They have clarified and simplified their position. 

There is no disagreement that the water that I will identify exists. In fact there is additional unallocated drinking water held in reserve in the current system that is greater in volume than the proposed Traveston Dam Stage one. 

* The Ministers point out that they have legislated an "objective" that 66% of all water that passes through the Wivenhoe/Somerset dams system is to reach the Brisbane River mouth and the remaining 1/3 is for the citizens and guests in South East Queensland.

This means that of the current 76% of water in our dams only 1/3 of that is available to us or 25% of the dams' capacity. 

One may believe that if the Government legislated this requirement, then the Government can change it.

That the Government would not change it under any circumstances was observed when the McMah proposal was eliminated. This statement is supported by the recent letters from the Ministers.

Photos : copies of relevant pages 1 and 2 Minister Hinchcliffe letter to Mr Ron McMah. The 66% was made law in March 2007. Similar letter to me From Minister Robertson. "Mean annual flow" defined in "Brisbane River 66%" tab. All other other matters including the important pumping procedures raised are dealt with in Hinchcliffe Pages 3 & 4 are are not relevant in this section.

Mr McMah (Grazier from Imbil) had proposed access to 80,000ML of surplus water in the Wivenhoe/Somerset system which had been identified by the Government appointed Engineers GHD when considering raising the wall of the Wivenhoe dam. It requires an Environmental Impact Study (EIS) which we welcome. It takes the place of the independent review sought by us.

It was part of his Plan, in conjunction with expansion of the Borumba dam to 2 million megalitres, for further water and storage for lean times via a two-way pipeline to the Wivenhoe/Somerset dams. The Borumba dam is 60klm over the hill in the Mary Valley. The Plan is fully discussed throughout this web-site.

We have reviewed that the majority of this surplus water is flood water not currently capable of being controlled. The use of this major storage to assist in controlling them was not identified to the "Water Resource (Moreton) Plan" originators. The ecological and social advantages and disadvantages of doubling the storage capacity by the use of the expanded Borumba had not been considered when the 66% decision was made. The environmental impact study (EIS) could be expanded to make this a very public appraisal as we have seen with the Traveston proposal.
Photo : Courier mail article where scientists identify that flood water has degraded the water quality in Moreton bay. 22nd October 2009

Access to this water would have eliminated the Traveston proposal with the Mary River running free and, in addition, provided much needed storage and ecological control of the surpluses of the Wivenhoe/Somerset system in the times of large rainfall events.

In all the McMah proposal would have provided 210,000ML in a few years compared to the Traveston of 150,000ML by year 2050. (October 2009. Recently released Environmental Impact Study review by the Coordinator General seems to indicate that the Traveston is confined to stage 1 or 70,000ML)(See Brisbane River 66% below)

Early observations using the Governments figures are that the selected 66% requires a reduction to approximately 59% to complete the McMah proposal. A significant trade-off is better control of water through all seasons for the ecology and us incorporating very large storage facilities. Those facilities would more than double the capacities of the Wivenhoe/Somerset dams.

How the Government's "objective" of 66% is to be achieved and monitored is the subject of the "Moreton - Draft Resources Operational Plan" of January 2009. Government sources confirmed that it is still a draft with expectations of completion by December 2009. That date is almost 3 years after the decision of 66% requirement became law. 

Important note:
A more detailed examination of the 66% requirement is accessed by the "Brisbane River 66%" tag or by clicking this.

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Hinchcliffe Pages 3 and 4

All 4 pages are set down for clarity and my observations are provided

Page 2 :     Mary River 85%

Most of that 85%, if not all, is flood water and, as we have recently seen, particularly damaging to the point where it enters the sea similar to Moreton Bay. It is quite capable of creating a statistical aberration due the method used calculating the "mean annual flow".

More : Mary River 85%

Page 3 & 4 : Pumping and storage
(Minister Hinchcliffe heading "Impact on flood immunity downstream from Wivenhoe Dam")

Full use of the expanded Borumba Dam as a storage facility for the Wivenhoe/Somerset system can be made with or without the use of the flood compartments of those dams. Non use of the flood compartment will take a little longer to bring the joint operation to full capacity.

Raising of the operational level has been discussed by engineers GHD engaged by the Government. What that means is that part of the flood compartment can be used successfully. They did not quantify the volume and it appears from his letter the volume is still to be identified.

More : Pumping and Storage

Pages 2 & 3 :

Consideration of "uncommon events" (Large scale rain depressions)
Dynamics of the Moreton Area
Other developments considerations drawing water from the Brisbane River

Review on "Hinchcliffe pages 3 & 4"

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Click for More on this. It follows the opening remarks.

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Recent water restrictions were caused, not by a dramatic drop in summer rainfall in catchment areas during the rainy summer months, but by an absence of the random deluges upon which we depend.

Dam managers refer to these deluges as "uncommon events" by which they mean the Monsoons, Cyclones and large-scale rain depressions that account for more than half of South East Queensland's inflow into the dams.
Photo: Most likely the most important piece of information offered to the public during the so-called "drought" period.

The term "uncommon events" is a misnomer. If anything, large-scale rain depressions are quite common in the catchment areas. If they were not, South East Queensland would be in far more serious trouble than it is now.

To put it all in perspective, a monsoon, cyclone or large-scale rain depression can fill our dams to capacity within a few days, something that would take nine years on a basis of summer rainfall alone.

Historically, monsoons, cyclones and large-scale rain depressions occur in clusters. There were six in the 13 years from 1988 and four in the four years from 1971. The 34 events in the 111 years from 1841 to 1970 followed a similar pattern.
Photo : All high rainfall events from 1841 to 2006 incorporating Brisbane City flood heights and rainfall 

Sporadic deluges deliver vast quantities of water in a short time. An "uncommon event" filled the then new Wivenhoe Dam to overflowing in 1988 and again in 1989. Since then, "uncommon events" have refilled it four more times, three times to overflowing.

Some sporadic deluges only partially affect catchment areas. I have not factored partial hits into my submission even though, over the past two years, four of them have contributed 49 per cent of the 58 per cent current rise in dam levels.

Whether the result of full-blown or partial events, a potentially rich harvest of rainwater has surged over spillways and into the sea, squandering a surplus that should have been captured and held in reserve.
Photos: Impact of "uncommon events" in the life of the Wivenhoe dam. 

Recent legislation in response to water shortages has mainly focused on the three-stage Traveston Dam proposal, an expensive and ill-advised project that would inundate the Upper Mary Valley.

***Review of Stanley River (Somerset catchment) and Mary River (Traveston catchment) Both are sister adjacent catchments. ***

Since rainfall patterns in the Mary Valley catchment closely resembles those in the Somerset catchment, which is our main water provider, there seems little prospect of the Traveston Dam consistently bridging "dry" periods. Notice that the overall pattern is the same. Periods without "uncommon events" have almost exactly the same rainfall. 
Photo : Summer rainfall comparison Somerset and Traveston catchments.

"Uncommon events" have generally 10 per cent higher rainfall than the Somerset. Unlike the backup Wivenhoe Dam for the Somerset, the Traveston is designed to release major floods. As "uncommon events " are our major source of water, it will be interesting to see how it performs in times without them as happened in the years 1975 to 1988. With the dam not yet approved or built, I do not think I will be on the planet to view the result of such a period.

There is no need to wait that long. Discussions with a CSIRO geologist confirm her paper of two years ago that both of these Rivers were different from the norm. Headwaters rise in the Mt Mee area and turned normally to the coast. A geological anomaly occurred and they began flowing the other way to the west to find their way out to the sea by other means. Both have roughly the same catchments for the dams that they serve, or are to serve. The geologist confirmed that there are no geological impediments to their flow.

The Somerset Dam was in place for the period 1975 to 1988 with the Wivenhoe being commissioned in 1986. The dam inflow records should mimic the proposed Traveston dam. I have requested output from computer models and Somerset dam records. While the QWC is most helpful, those records rest with another Department. (September 2009)

***

The Wivenhoe Dam, built partly as a mitigation measure following the disastrous 1974 Brisbane flood, remains very much the Somerset Dam's junior partner when it comes to delivering a consistent water supply.

The solution is not to build a new dam but to capture the vast volume of water - more than the Traveston Crossing project could ever provide - that is lost whenever an "uncommon event" takes place.

Rather than being dumped over the spillways in the Wivenhoe/Somerset system, surplus water should be piped to the Borumba Dam for storage, available for release into an expanded grid system during times of shortage.

This proposal would entail expanding the capacity of the Borumba Dam to two million megalitres. Government appointed Engineers suggest that the dam's potential capacity could be higher but two million megalitres will suffice for now.

With a short connection to the water grid's Northern Interconnector linking Brisbane's northern suburbs to North Pine Dam and, eventually, to the proposed Traveston Dam, all overflows from major dams in South East Queensland, including the Borumba Dam, could be stored for future use. 

Such a project should be approached carefully. Nonetheless, on the basis of my calculations and research, the cost would be much less and the effectiveness far greater than for constructing the proposed Traveston Dam.

More detailed estimates - including pipes, pumping equipment, access roads, electricity, minor land resumptions, easements and intermediate stations - are canvassed on this website.

Initial advice from engineers suggests that an expanded Borumba Dam and associated pipeline could be built for less than $2 billion - compared with $3.1 billion for the Traveston scheme.

I began researching Queensland's water issues in 2006. I have no commercial or other interest in the outcome of this submission other than as a citizen of South East Queensland.

In compiling this submission, I have used my professional skills as a Chartered Accountant attained over several decades to compile and interpret data, supplementing statistical analysis with interviews with relevant experts.

The contents should be read in conjunction with a submission by Mr Ron McMah who came up with the idea of expanding the Borumba Dam to simultaneously solve South East Queensland's water issues while saving the Mary Valley from inundation.

***************

August 2009 Update

The Minister for Infrastructure and Planning, Stirling Hinchcliffe and the Minister for Natural Resources, Stephen Robertson, have responded to our proposal for a two-way pipeline from the Wivehoe/Somerset dams to a significantly expanded Borumba Dam 

They have provided a clearer view of their position and it is welcomed. The Government's reluctance to capture more water is based on an "objective" that 66% of the water flowing through the Wivenhoe/Somerset system is to reach the mouth of the Brisbane River. It is now legislated and we must conform.

This peculiar "objective" means that, of every three litres of drinking water flowing through the Wivenhoe/Somerset system, two litres must be released into the Brisbane River to find its way into Moreton Bay.

To conform to this objective, a volume of water equivalent to almost the entire capacity of the Wivenhoe dam must find its way into the dams each year on average. The annual yield of the dams has been determined by the Government as 361,000ML annually. As this represents 34% under their objective, the volume required annually is in excess of 1.06 million megalitres. The capacity of the Wivenhoe is 1.17 million megalitres.

While we applaud ecological common sense, we are concerned that the 66% "objective", born in the time when the river was thought to be in a severe drought, may have been skewed by the random nature of "uncommon events". 

For example, major floods of 1890 (5.3 metres), 1893 (8.5 metres) and 1974 (5.4 metres) are included in their calculations. Floods of that size have the capacity to distort percentage calculations presenting a statistical aberration. It also has the element of a short gap of 3 years and a long gap of 81 years. The current gap is 35 years and continuing. The Brisbane River heights used are Brisbane City heights.

What is certain is that the Government's "objective" cannot be achieved without the strong heavy volume and random flows of "Uncommon events" experienced in the life of the Wivenhoe from 1988 to to February 2001. They are our main water supply and environmental concern must be examined in the context of their very short life span of a few days followed by their protracted absence of up to 14 years at times.

The Wivenhoe Dam was brought into operation as a dam for additional storage of the Somerset Dam which sits just above it. It also serves as a flood mitigation dam. While the Somerset is our major supplier of water in normal times, the Wivenhoe catchment can fill the dams from scratch to full and overflow when "Uncommon events" engage its extensive Upper Brisbane River catchment.

Following on the Wivenhoe addition, in the same way, linking of the expanded Borumba dam will more than double the holding capacity of the Wivenhoe/Somerset dams. This will provide greater management control for both the Environment and ourselves and solve most of the problems that they are attempting to grapple with. 
Photo : Courier mail article where scientists identify that flood water has degraded the water quality in Moreton bay. 22nd October 2009

Extraction and storage for later return is provided for under the same Act of Parliament. We remain confident that greater volumes of water can be stored without environmental harm and most likely to its considerable benefit as this newspaper article suggests. We are convinced that statistics, based on the random nature of uncommon events, will confirm our view.

The Ministers and the Acting Executive Director of Regional planning and policy for the Queensland Water Commission have indicated their cooperation in providing these statistics and they have been sought.

We welcome a fair, objective and considered assessment of the ecological implications of our two-way pipeline proposal.

A review of the matters before us is as follows:

 * No-one disputes the availability of the additional 80,000ML of water from the Wivenhoe/Somerset system. Indeed, Government-appointed engineering firm GHD cited this volume when reviewing a 2006 proposal to raise the wall of the Wivenhoe Dam. It will require an Environmental Impact Study (EIS) similar to to stage 1 of the Traveston proposal. We welcome the EIS as it will cover all aspects and serve as the independent review we initially sought. 

 * An expanded Borumba Dam linked with a two-way pipeline from Wivenhoe/Somerset system not only has the capacity to cover all eventualities but also to provide an additional water supply of approximately 50,000ML. This figure is also not in dispute.

 * The available drinking water from the Wivenhoe and Somerset dams has been determined by the Government at 361,000ML annually. So far, only 280,000ML is released annually for consumption.

The so-called "drought" has created a perception that the present 280,000ML cannot be guaranteed if the remaining 81,000ML is released.

It is the random nature of "uncommon events" that has created this perception. Their departure is much more severe than any drought and the retention of 80,000ML will not solve a 13 year period similar to 1975 to 1987 when there was no "uncommon events". The Wivenhoe dam level graph is clear evidence of this statement. 

Our two-way pipeline would ensure continuity of supply with reserves built up in the Borumba Dam in times of plenty. As previously mentioned, the expanded Borumba Dam would be the largest dam in Queensland. 

 * Combined availability totals 210,000ML, or almost five times the output of the recently opened Tugun desalination plant which produces 45,000ML of potable water annually at a capital cost of $1.2 billion.

Another comparison is that 210,000ML is equivalent to the 150,000ML (revised down to 70,000ML)from all three stages of the Traveston project with a completion date of around 2050 plus 2 and 1/2 desalination plants of the four proposed on the North Coast of 25,000ML each. (October 2009. Recently released Environmental Impact Study review by the Coordinator General seems to indicate that the Traveston is confined to stage 1 or 70,000ML)

The cost of our two-way pipeline and Borumba Dam expansion, using engineering advice, is around $1.9 billion. The cost of the Traveston all three stages is $3.1 billion. Two and one-half desalination plant is unknown but the Tugun 45,000 capacity at $1.2 billion is a guide.

 * In reserve is the recycled water plant which may be useful for environmental purposes.

Reliable water supply is a basic human necessity.

Governments have a responsibility to safeguard the environment, but it must also satisfy the needs of its citizens and equitably balance the requirements of both.

                                    *******

To the citizens of South East Queensland

Solving South East Queensland's water problems: a cost- effective proposal based on statistics and history

August 2009 Update

The receipt of follow-up letters from Ministers Hinchcliffe and Robertson mentioned above have clarified and simplified their position.

There is no longer argument that the water we have defined exists, in fact there is more. In addition the hydrology and Engineering reports produced for the people of the Mary Valley and used so effectively to deflect our proposal are no longer mentioned.

The main circumstance on which the Ministers rely is in the preceding section. They have provided us with ample opportunity to request further information to satisfy ourselves and we appreciate that opportunity.

Our critique of the "terms of reference" of the Hydrology and Engineering reports and the way they were produced is no longer required and is excised from the following index.

The remainder is retained as interesting and important background to the lack of understanding of "uncommon events" when dealing with the life of the Wivenhoe Dam. The consequences emanating from their decisions or lack of them has had severe and costly consequences for the citizens of South East Queensland.

                                                       ********

June 2009 :  Following the May 2009 "uncommon event" in which the Premier declared SEQ a disaster area, it is time to make a concise review. It is completely on this Index (Home) page and divided into two sections:-

*  The volume of our available water supply and its individual sources. The section includes the problems that occurred during the life of the Wivenhoe Dam and are still occurring due to a lack of understanding of our major water source, "uncommon events". A great deal of this major resource is now lost over the spillways.

*   More surplus water than the Traveston all three stages. Based on official Engineering evidence, there is more surplus water in the Wivenhoe/Somerset/Borumba expanded, available within a few years at less cost than in the Traveston proposal all three stages to be completed by 2050. We will review the evidence so that you can form your own conclusions. 

As we will see, the May 2009 event only covered the catchments to a limited degree missing the full force of this event. It still gives us a view of the power of an "uncommon event".

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Index : If you click on a document to examine it remember the number of the paragraph. Depending on how your computer is set-up, it may not return you directly to the picture you were examining. When you click the back button to return, it will bring you back to this page. Click on the page numbered underlined index section that you were examining to return directly to it:-

The worst drought in 100 years ?

Examination of the reason for our depleted dams was carried out in the original "Home" page. That page is maintained in CURIOUS DROUGHT Tab where the reason for the depletion is fully examined and flows on to this Index.

The volume of our water supply and how it is misunderstood

1.   A snapshot of our natural and reconstituted water supply
       (1.01) Years to fill the Wivenhoe/Somerset from scratch without withdrawal of water
     (1.02) The story of the Wivenhoe's short life
     (1.03) The most recent May 2009 event plus the three events before it   
2.   Mathematics and frequency of "uncommon events"
    They are observed on average every 3.7 years and only for a few days of high intensity saturation rainfall
3.   Guesswork of "uncommon events" elimination by large storage
4.   Next "uncommon event" on relatively full dams
5.   Decision makers Past and present
6.   The Puzzle and good outcomes of the solution  Original page of this website. 
7.   Final arbiter that will show how our dams and rainfall engage each other With full and overflowing dams similar to the first 13 years of the Wivenhoe, SEQ citizens will be entitled to ask if our leaders know what they are doing. If they do not occur within the time frames outlined, then the same can be asked of me.
8.    Alert to Minister Hinchcliffe in my letter 3 weeks before the May 2009 event
9.   Wivenhoe Dam introduced a new set of circumstances 
10. What exactly are "uncommon events" ?
11. Understanding is more mathematical than hydrological
        the mathematics of a 3.7 year average
12. The circumstances unfamiliar to our decision makers
13. Reaction of our Leaders
       13.01   1989   Ms Goss/Rudd/Swan/Garrett
       13.02   1996-2007   Premiers Beattie and Bligh
       13.03   2005-2006   Premiers Beattie and Bligh
14. Remaining plank of "Emergency" legislation
15. The advantages of the proposal (the Ron McMah plan)

Comparison of the McMah plan with the Traveston, all three stages

            The mechanics of the proposal 

            How much additional water and where do we store it?

           16. Original proposal
           17. Scope larger than first thought
           18. Additional water available Wivenhoe/Somerset
           19. Additional water available  Borumba Dam
           20. Purpose of the Borumba Dam expanded to 2,000,000ML
           21. Satisfy Most People
           22. Flood water collection and pumping
                   
            23  Support of Prime Minister's Senior policy advisor
            24. Uncommon events the ultimate arbiter of our proposal v Traveston

"Uncommon events" that measure up to the rainfall requirements of SEQWater and listed in the picture on right, have the capacity to fill our dams from scratch to overflow in a few days. The picture on the left is a comparison with other sources of our water supply and the years that it would take them to fill an empty dam.

It is the overflow from "uncommon events" that we are concentrating upon. Government appointed Engineers GHD identified an additional 80,000ML\a available if the Wivenhoe dam wall was raised (their findings in the second section). This is flood water not now retained. It did not proceeded due to complications with existing infrastructure. This is a minimum volume available as it does not count flood water that most certainly would overflow even the raised dam wall. 

Back to INDEX

The story of the Wivenhoe for its short life of 23 years from commissioning in 1986, is told in this picture with the wide border. A click on it and you will see that there are 6 events of such magnitude that they filled the brand new dam from scratch and refilled it four times, three of them to overflow. 

One cannot fail to notice that they are our main water supply. After a quite normal gap of 8 years, four small events retrieved the situation to 74% full. These four small events, derived from near misses of low pressure systems over the catchments, were well below the qualifying standard set by SEQWater. Most were not far enough west to engage the Upper Brisbane River catchment known as the Wivenhoe. 

Back to INDEX

The most recent May 2009 event failed to qualify as an uncommon event. As we have all experienced this May 2009 event, it gives one an appreciation of the volume of water produced by the events in the short life of the Wivenhoe. This recent May 2009 low pressure system had Premier Bligh declaring "the worst drought ever recorded" over and promptly declared SEQ a disaster area. 

As we have seen in the curious drought tab, the "worst drought" was simply the erratic nature of "uncommon events" with summer rain in the catchments quite normal. Unfortunately the May 2009 event left the dam catchments short on rainfall , as occasionally happens. The excellent rain failed to come west sufficiently to cover the Upper Brisbane River, Wivenhoe, whole of catchment This is viewed in this picture with comparisons with the 6 that occurred in the life of the Wivenhoe.

It had the capacity to rival the experience of the Wivenhoe and overflow the dams but performed to a limited degree.

These four small events, which produced 49% of the 57% rise in our dam levels, plus the 6 majors events in the short life of the Wivenhoe are concrete evidence that "uncommon events" large and small are our major water supply.

The frequency of "uncommon events" prepared by me from the Bureau of Meteorology records shows that that they are frequent and not uncommon. 

The observation of "uncommon events" is more mathematical than hydrological. They are observed on average every 3.7 years and only for a few days of high intensity saturation rainfall.  Because "uncommon events" are such a large portion of our water supply and their behaviour somewhat erratic, in the case of our catchments, hydrology has little bearing in determining our available water supply.

 This is starting to be recognized by the QWC's change to a stochastic approach (best guess under the circumstances, Wikipedia) when establishing the yield or available water supply from the Wivenhoe/Somerset dams. 

The guesswork is eliminated by having storage in the Borumba Dam, expanded to 2,000,000ML or almost twice the size of the Wivenhoe and larger than the Burdekin, for all major dams in SEQ as they overflow with substantial loss of available water. This is a far superior outcome in water volume and cost than the Traveston proposal.

Back to INDEX

With the Dams currently at 75% level, summer rainfall and the desalination plant should maintain the level around that figure. The next "uncommon event" that measures up to those 6 events in the life of the Wivenhoe will heavily overflow the dams and bringing the Traveston proposal into serious question.

Back to INDEX

In my view, we have had a succession of leaders and those responsible for our water supply appearing to have not fully understood, or were not aware of, the relationship of "uncommon events" and the Wivenhoe/Somerset system. The 19 years of decisions or no decisions are interrelated and have subsequently proved costly and disruptive to the citizens of SEQ. 

As a consequence the people of the Mary Valley needlessly face the same predicament. In addition the people of SEQ will permanently lose a valuable asset due to a major storage facility in the Borumba dam being lost in the dam wall footings  in stage 2 of the Traveston proposal.

Before my mate Bernard from one of the Sunshine Coast ALP branches gets upset, I have to say that I found the problems that they faced more difficult to solve than a Rubik Cube. The Bureau of Meteorology facts were not agreeing with my eyesight of a depleted dam. 

The folks involved were, and some still are, pragmatic politicians who rely on the opinions of the electorate. I will present the facts on which I formed my view so that you may form your own opinion.

Back to INDEX

The puzzle is complex. It is laid out in the CURIOUS DROUGHT tab being the original Index (Home) page and tens of thousands of visitors to this site are familiar with it with 78% adding it to their "favourites". The essential elements are that there is two types rainfall that fill our dams.

When we examine the solution to the puzzle we will find that more water can be collected and stored between the Wivenhoe/Somerset and the Borumba dam, just over the hill from the Wivenhoe/Somerset, than the Traveston proposal all three stages. The Mary River will run free and partial flood mitigation of Gympie will occur. 

An added bonus will occur if the short connection from the Borumba to the Northern Interconnector is made, then all major dams in SEQ will have access to storage.

The final arbiter to my conclusions in this website will be "uncommon events" themselves. When the next "uncommon event" fills the Dams to overflow, people will be entitled to observe whether our Leaders know what they are doing. If it does not occur within the periods outlined in this website, the same can be asked of me. 

With the Dams full, the following "uncommon event" will overflow the dams. My position, if not already clear, will become obvious to all and, in my view, the expensive and irreparable forward planning will come under serious questioning. - I wrote those two paragraphs before the May 2009 event. As illustrated above, if the low pressure had been a few kilometres to the west it would have been complete with the dams overflowing, instead those paragraphs are still current. 

Extract from my letter to Hon. Mr S. Hinchliffe, Minister for Infrastructure and Planning, sent on the 23rd April 2009 three weeks before the May 2009 event

"The way I see it, the difficulty for you and all who support the Traveston is that on the mathematical certainty of the return of the “uncommon events” the dams will overflow. That by itself should have people in SEQ questioning if those in charge understand what they are doing. Historically there has been 11 “uncommon events” within 1 year of each other (April 1988 & April 1989 for example) and there will be a tremendous loss of water over spillways with full dams. In my view justification of the Traveston will be under severe stress and storage in the Borumba Dam together with its additional yield, vindicated."

I am conscious of Machiavelli's sixteenth century observation that "you cannot win against the Government". His view was that one would make enemies of those who support the status quo and for those who might like a change, they are not sure how it will affect them. 

However King Canute found he could not win against the "tide". For this exercise substitute "tide" with "uncommon events". The "tide book" is called "Frequency of uncommon events" and appears in the first paragraph. The tide came in in May 2009 and the tide book indicates a reasonable chance that a much higher tide in the catchments will come in again within one year and a 70% chance within 3.7 years.

The addition of the Wivenhoe Dam to SEQ water supply in 1986 generated a set of circumstances that were unfamiliar to our decision makers. Discussions with an Engineer, whose name appears on the dam plaque, confirm that the Dam is both a storage dam and a flood mitigation dam. The Somerset was inadequate to hold the waters of the coastal Stanley River catchment and now releases into Wivenhoe. 

The inland Upper Brisbane River, with 23% less rainfall, feeds directly into the Wivenhoe and is very much the junior partner in normal times even though its inefficient catchment is three times larger than the Stanley River catchment. It comes into its own at flood time with 250mm to 300mm whole of catchment producing an enormous volume of water and working in conjunction with the Stanley River can fill the dams from scratch.

Our Dam managers, designated as SEQWater to save confusion with the new corporation Seqwater, have publicly told us that these dams need what they call "uncommon events" to fill these large dams. It seems that our past Hydrologists, recognized as world class in my readings, were aware that Summer Rain was inadequate for our needs even with the Wivenhoe dam in place. They proceeded with the Wolfdene Dam, situated on the Logan River, after the Wivenhoe was commissioned in 1986. 

The Wolfdene was cancelled in December 1989 as a direct result of our decision makers being unfamiliar with the new circumstances. It is an acknowledged error. This error was first recognizable in 1992 with the dam levels dropping to 70%. It is further discussed a little later on this page.

The main contributor to our water supply are "uncommon events" and summer rainfall. An understanding of how both interact with our dams is essential in providing a base for decision making.

It is necessary to have a clear understanding of "uncommon events". The effects of Monsoons and Cyclones are rare, however large scale rain depressions are comparatively common and they pay little attention to what time of the year they occur. SEQWater points out that 350mm of rainfall in the Stanley River whole of catchment (Somerset) and 300mm in the Upper Brisbane River whole of catchment (Wivenhoe) is required to create an "uncommon event" that will fill both dams from scratch in a few days. 

The Wivenhoe is the main reservoir of both Rivers. My examination of rainfall data from all rainfall stations in the catchments showed that the "Wivenhoe" catchment twice only in the twentieth century exceeded the 300mm. It was necessary to reduce the requirement to 250mm to match the frequent "uncommon events" in the "Somerset" catchment.

They are an essential element in our water supply and without them our water supply would be in serious trouble.

It is my view, and it is worth restating, that the lack of understanding of "uncommon events" is more mathematical than hydrological. Hydrology determines the point at which the dam will fail to deliver on historical data (HYNF). We are interested in major events contribution to our water supply and more importantly their overflow of the dams which is now lost. 

Rainfall of 400mm in a few days is an uncommon event whereas 4 months of rainfall at 100mm a month provides just a trickle into the dams. 

Major events that happen every 4 years is something that the human mind can comprehend. Examples are the Olympic Games or World Cup Soccer. The difficulty comes when it becomes an "average" of 4 years and those events occur anywhere from 1 to 14 years apart to produce that average. It is a mathematical equation that most of those events will occur in less than 4 years and very few in the region of 14 years.

The whole process of identification and timing leans towards Mathematics for answers.

The attached Dam level Graph of the Wivenhoe supplied by SEQWater shows the impact of "uncommon events" in the short life of that dam. 

The attached "frequency of uncommon events" designed by me from official Bureau of Meteorology records, records their timing and severity for the 160 years from 1841 to 2000. The summary on the right hand side reveals that storage for a 14 year period is required. A  task easily performed by an expanded Borumba Dam which we will examine. 

With 70% of uncommon events occurring within 3.7 years, there is a significant surplus of water under any conditions as occurred in the life of the Wivenhoe (see graph just above) where 6 events occurred. There was sufficient water to fill it from scratch and to overflow many times. 

And so it is in relation to our water supply in SEQ that all facets of the equation came into play and, in my view, our best brains were, and still appear to be, oblivious to the actions of "uncommon events". I refer to to the 23 year life of the Wivenhoe Dam 1986, being the date commissioned, to 2009 and also the period before the dam back to 1974. Those events were:-

1974...............................1988..89......92......96......99....2001................2009

The dam level chart above tracks the effects of these 'uncommon events" which are our main water supply.

You will note that the period 1974 to 1988 was the longest gap recorded since 1841. When read with the dam level graph, you will also note that 1988 and 1989 filled the dam from scratch to overflow, refilled the dam four times, 3 to overflow, and finally recording 2009 as an event without the accompanying dam overflow.

We have just missed 4 events which failed to come fully into the catchments. They were August 2007 brushed the Coast, May of 2008 stayed out to sea and more recently cyclone Hamish also staying out to sea. The April 2009 and, as witnessed above, the May 2009 events did not fully come into the catchments.

The soon to be Premier Mr Goss and his chief of staff Mr Rudd (now PM) went to the 1999 election with the cancellation of the, well underway, Wolfdene dam on their platform. The Wivenhoe was filled to overflow by the 1988 and 1989 events and cancellation seemed logical. As they won the election, it was a collective decision and is now an acknowledged error.

The prior gap in "uncommon events" from 1974 to 1988 being 14 years was ignored and by 1992 the dam levels had dropped to 70%. It was clear then that summer rain was insufficient for our needs and, without "uncommon events", dam failure was inevitable. "uncommon events" obliged with continual overflows thus keeping the prospect from view. In February of 2001 they went on their quite normal walkabout thus exposing the 1989 error and the inaction over the intervening years to eliminate this possibility.

Premier Beattie had the reasonable attitude to water that there was plenty of it and it was not high on his agenda. "uncommon events" had refilled the dams and cloaked the looming problem. The following dam level graph tells us of the unfolding problem. 

In February 2001 the dams were full from the last "uncommon event". The fall of 22.0% in 2002 did not create any fuss. The 2004 year saw above average Summer rainfall limiting the drop to 2.1%. In 2005/06 the realisation of the magnitude of the problem was there for all of us to see in the depleted dams and it appeared that a major drought was underway in the catchments.

Our Leaders classified the depleted dams as "the worst drought in 100 years". Unfortunately they were the victims of a statistical aberration. You will see in    Bureau of Meteorology and Decision Makers that rainfall in he catchments had been comparable with the long term average in the summer months but there was a deficiency of 20% in the low water producing non summer months. 

The statistical aberration was that rainfall in the catchments had never been lower than 80% of the long term average as verified by the Bureau email in the sections mentioned. So good rainfall could and did end up in the lowest decile being the lowest on record. The decile map, promoted and used to verify the "drought" was that aberration. 2.8 million people in SEQ, including me, believed this to be the case until I checked the facts available in the Bureau of Meteorology.

Again "uncommon events" were the key. This graph shows the rainfall in 6 years lots, being the period of the "worst drought" , that almost one half of the 20th Century had experienced the same condition. Those left of centre did not have an "uncommon event" with one exception out of the 24 "uncommon events of the 20th century. The remaining 23 are on the right. 

While they impact on the overall rainfall to a degree less than expected, the explanation is that 400mm in a few days being an "uncommon event" is not the same as 4 months of 100mmm. It is the intensity of the rainfall that creates the "uncommon event".

With little room to move, the reaction was the Grid system which was basically the only alternative as "uncommon events" could not be relied upon to intervene nor were they perceived as the answer as the situation was believed to be caused by a "drought". We have seen since four events (January and November 2008 and April and May 2009) that were significantly below the standard set by SEQWater but filled 49% of the 57% of the rise in dam levels from 18% to the current 75%. There were other good initiatives such as raising the Hinze Dam wall, water tanks and public education.

Premier Beattie announced that he did not wish to have a situation that we faced occur again and formed the Queensland Climate Change Centre of Excellence (QCCCE) to avoid unexpected climatic events. They proceeded to produce "the drought to 2007" which is examined in the Federation Drought tab. Their formation is evidence that the underlying nature of the perceived "drought" was not understood.

Premier Bligh has declared "the worst drought on record" officially over (May 2009) In 2007 a decile map was used to convince us that our depleted dams were the result of drought whereas the percentage map for the same water shows 80% with Bureau records revealing the deficiency of 20% was in the low water inflow producing non summer months.

 Hardly a drought in anyone's language. It is my view that the "worst drought" had the appearance of being scripted, produced and directed by those who should have perceived the problem in the first place, placing a great deal of unnecessary stress on the Premier and residents of SEQ particularly those in the Mary Valley.

For the record, the Bureau of Meteorology easily accessible record maps show that for the last 2 years the drought map showed no drought in SEQ. The decile map that the Premier distributed to all SEQ homes in 2007 to convince us of a bad drought, showed average rainfall compared to the long term average. The percentage map showed average rainfall compared to the long term average. Coupling  dam levels with "drought" and ignoring the evidence of the hydrological situation is an interesting scenario. 

In my view, it is Premier Bligh's commitment to "the worst drought in 100 years" that has suppressed the view of the underlying causes, the recognition of which may have produced a better result and not left us with the following legacy.

The remaining major plank of the "emergency legislation" was and is the Traveston Dam proposal. It is a three stage approach stretching out to 2050 at an approximate cost in today's terms of $3.1 billion including main road relocation for an all up water supply of 150,000ML annually. Stage 1 (70,000ML), on which the Environmental impact study (EIS) is encountering problems with Environmental concerns, has been delayed by the Coordinator General.

  Based on official Engineering evidence, there is more surplus water in the Wivenhoe/Somerset/Borumba expanded, available within a few years at less cost than in the Traveston proposal all three stages to be completed by 2050. 

We will review the evidence so that you can form your own conclusions and also review how the Premier Bligh's guarantee to the people of the Mary Valley of this comparison was handled and its outcome. 

 * The mechanics of the proposal
 *  The use of the Hydrology and Engineering reports, and amendments thereto, by all sections of Government and our evidence of the lack of precise and agreed "terms of reference", usual in such reports, which contributed to the negation of  important aspects of those reports.

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* How much additional water and where do we store it?
     * Original proposal
     * Scope larger than first thought
     * Addition water available
         * Wivenhoe/Somerset
         * Borumba dam expanded
     * Satisfy most people
     * Flood water collection and pumping

There is not much point in determining a problem if one cannot offer a solution. As we shall see, the surplus water is proven by Engineers but where to store and return it to the system at a later stage? 

Earlier Mr Ron McMah, a grazier from Imbil in the heart of the Mary Valley, had, at a public meeting, put a proposition to current Premier Bligh that the Borumba Dam be increased to a capacity of 2,000,000ML or twice the size of the Wivenhoe (see photo from ridge looking down at the dam). The Engineers say that it can be increased beyond that capacity if required. The additional collection from the Borumba together with surplus water from the Wivenhoe/Somerset would, in his opinion, exceed the yield from the Traveston Stage 1 which would not be necessary.

He added that Weirs in the Mary Valley should be investigated to complement any shortfall in the proposal but later withdrew that aspect in his EIS on the Traveston. The other aspect was the storage of water from the Wivenhoe/Somerset system in times of plenty for later return. ( it is this aspect on which the Ministers now rely. Subsequent to that meeting it was enacted, 5 months later, that 66% of all water that flows through that system is to find its way to the mouth of the Brisbane River). For an update read the Up-date August 2009.

The Deputy Premier Bligh gave him an "iron clad look-you-in-eye guarantee" that if it stacked up then that would be the way that they would go. Premier Beattie toured the Borumba Dam with Mr McMah.

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I was unaware of Ron McMah's plan having been drawn by curiosity to examine "the worst drought in 100 years". The solution required large storage and I was directed to Ron by a friend of long standing Trevor Herse from the Gold Coast. Trevor and I together with Ron in July 2007 followed the review of the dam on the same path as taken by the review of Premier Beattie. This project has been a joint effort of the three of us for the last two years since that review with this website first appearing in August 2007.

The combination of the available flood water from "uncommon events" from the Wivenhoe/Somerset system under this research plus the available water from the expanded Borumba to contain the "uncommon events" not only surpassed stage 1 of the Traveston but exceeded the entire three stages of the Traveston proposal.  

There is some possibility that some or all of the proposed four desalination plant to be installed in the north coast will not be needed saving up to my ballpark estimate of $3.0 billion based on the $1.2 billion Tugun desalination plant.

We will now proceed to see if the plan "stacks up" and follow it with a through with a detailed analysis of objections raised by Government sources. Bear in mind that an independent review, free of those who do business with the  Government, was part of the McMah proposal.

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Here we have factual calculations by Engineers GHD that conducted a "desktop" review of all Dams and Weirs in SEQ. Examination of the Wivenhoe was based on Department of Natural Resources and Water (DNRW) Historical Yield No Failure (HYNF) conducted in December 2005.

They considered the additional water that could be harvested by raising the dam wall of the Wivenhoe in their section "Augmentation of the Wivenhoe Dam". You will see from the tabulation on page 667 attached that an additional 80,000 Megalitres (ML) on an annualised basis could be achieved. They also advised of the difficulties faced by raising the wall and it did not proceed. Note: the yellow addition is mine for convenience.

HYNF indicates the minimum volume that can be retained without failure based on past rainfall. What we are measuring here is basically flood water from "uncommon events". There is therefore a great deal more water that flows over the raised wall extending the lowest volume significantly higher than 80,000ML on an annualised basis.

The backup to this evidence is the Wivenhoe Dam itself. Six events not only filled the brand new dam but overflowed 3 out of 4 times that it was replenished.

On its own, the Wivenhoe/Somerset far exceeds the Traveston stage 1 of 70,000Megalitres annually.

At our meeting with the now Minister Hinchcliffe in late January 2009 the QWC representatives stated that the yield of the Wivenhoe/Somerset included the flood water. The Minister seemed to agree. It is simply not possible to include in the yield that water that now goes over the dam wall and is not capable of being retained at flood time. It is a proven excess somewhere in region well above 80,000 Megalitres on an annualised basis. (Refer to Up-date August 2009 for an up-to-date position)

We will now examine the purposes and contribution of the Borumba Dam expanded to 2,000,000ML being twice the size of the Wivenhoe.

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The Borumba Dam is 60klm over the hill from the Wivenhoe/Somerset in the adjacent Mary Valley. It is currently a small dam with a capacity of 46,000ML and a yield of 32,000ML. 

The same Engineers GHD in their "desktop review" section on this dam in 46 page review commencing on page 532 concluded that the dam wall could be raised as high as 320 metres above sea level ( Page 539 3.12.13). However, at 230 metres above sea level (about 100 metre wall) the calculations on their graph indicate a capacity of 2,000,000ML or a little under twice the size of the Wivenhoe and larger than the Burdekin dam. 

1. A primary two way connection to the Wivenhoe/Somerset. A small secondary connection to the Northern Interconnector would provide storage for all our main dams in SEQ.

2. Yield in the dam expanded to 2,000,000ML increases from 32,000ML to 82,300ML. Of the additional 52,300ML, 30,500ML is identified by Engineers GHD based on NRM & Water HYNF calculations of February 2006 for a dam of capacity of 460,000ML and carried out specifically for this study (second picture - both yield and study base first 2 lines). The yellow calculations are mine to assist in reading. 

Raising the dam wall to 2,000,000ML will produce a further 21,800ML based on existing stream flows and other evidence as "uncommon events" will not be retained by a dam of 460,000ML. It has a smaller catchment but is hard rock, deep and with little seepage. For example the 1999 event, being the same as recorded in the Wivenhoe/Somerset, had the equivalent of one half of Sydney Harbour go over the dam wall in a single day of a 5 day event. There is supporting evidence at the Borumba Dam tab.

3. The Mary River would run free. When the Borumba (52,300ML) is considered in conjunction with the Wivenhoe/Somerset (80,000ML) and the yet to be identified significant surplus beyond the HYNF calculation, there is at least the equivalent and, most likely significantly in excess of, the whole Traveston proposal. The Traveston proposal is for three stages totalling 150,000Megalitres and to be built finalising in 2050 at an approximate cost of $3.1 billion including main road relocation.

4. There is the added benefit of flood mitigation in Gympie. The expanded dam to 2,000,000ML will withhold 36% of these flood flows from uncommon events being the estimated flood flows from Yabba Creek on which the Dam is situated. See Hydrology Mary V.

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Although it was not my primary intention to stop the Traveston proposal, we have a responsibility to the Mary Valley people to utilise all our resources before prevailing on their way of life. A joint use of the Borumba Dam expanded to 2,000,000ML is all we ask. This seems to satisfy most people. The Borumba is the second stage of the Qld Government's Traveston proposal. "Save the Mary" people have a link to this website and senior conservation people have approved of this site.

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In this area we were assisted by an Engineer who has his name on the Wivenhoe Dam Plaque. He provided extensive calculations on pumping aspects which he has since updated. The GHD report mentioned prior in relation to the Augmentation of the Wivenhoe was also helpful in assessing the operation of holding and pumping these large volumes of water.

The plan is extensive and laid out in Final Solution and EIS tab in order to minimise this index page. The plan is contained on pages 27 to 41 of my EIS lodged under the alternatives section of the EIS on stage 1 of the Traveston.


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We have the support of a Senior policy advisor to the Prime Minister whom we have kept informed from well before his election to Governing party. The support is on the basis that we have asked "An independent review of our material and their material and if there is something in it then a more detailed review be conducted". He has pointed out that it is the State Government responsibility but has conveyed his support to the Minister.

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As I have said previously, uncommon events themselves will be the ultimate arbitrator. The vision of them overflowing the dams and the water wasted will be powerful in persuading the citizens in SEQ that storage was the correct answer. Depleted dams can be attributed to any number of factors and the one selected "worst drought in 100 years" has a case to answer when the facts are applied.

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