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.

May 2009 : No change from last update.

This section is designed to draw attention to the decision making process of our Leaders on the entering into and emergence from a rare period of "uncommon events" in the life of the Wivenhoe Dam. In my view they are quite similar, one being made in a time of "plenty" and the other when the "plenty" was withdrawn.

Once the myth of the "worst drought in 100 years " is dealt with and uncommon events are understood, the decision to cancel the Wolfdene Dam comes into stark perspective.

The Dam was cancelled in early 1990 shortly after a change of Government in December 1989. The Wivenhoe dam had been in operation for four years. 

Wivenhoe was clearly a storage and flood mitigation dam for the Somerset and was positioned below the Somerset on the Stanley and Brisbane Rivers junction. The chart outlining the Summer Rains for the last 96 years supports this contention. In its own right it provides little to our water supply except for infrequent "uncommon events". The Somerset has a much more efficient catchment although much smaller in capacity and catchment area. Nevertheless, with higher rainfall, it provides most of our water supply. Reference the "Wivenhoe Dam" button .

The Water Engineers and Hydrologists were obviously aware of this. The Courier Mail has made mention of a Key advisor on water being a world class Engineer and Hydrologist involved in research and recommendations for all of the State's major Dams including the Wivenhoe and Wolfdene dams. 

The Government had purchased all of the land required for the Wolfdene dam. In dispute were a few blocks on the thirty year mark. Reference is direct contact with the Dam Manager at that time though our common interest in school activities. He and his Chairman were removed shortly after the New Government took over.

I understand the Wolfdene Dam was to be a major Dam in the category of the Wivenhoe as described in the pages of the Courier Mail. It was to be located just south of Brisbane.

The Gold Coast Bulletin leaves one in no doubt as to their position on the cancellation of the Dam, the reasons why and who they believe is responsible. The Bulletin appeared unaware that the people mentioned went to the 1989 election on the basis of cancellation of the Wolfdene Dam and supported by the Liberal Party.

The Gold Coast Bulletin has arrived at a conclusion that they lost control of their water asset, the Hinze Dam, because of the lack of planning of the people mentioned. The Bulletin appeared unaware of uncommon events in the same way that our current leaders are. The past decision makers mentioned on their front page appear to have overlooked, or have been completely unaware of the implications of the natural occurrence of uncommon events of 1988 and 1989 referred to later in this section.

To add further balance to this subject, SEQWater operations manager drew our attention to four uncommon events occurring in the years 1986 to 2001. 1986 was the start of the Wivenhoe and the inflows of 1992 and 1999 were readily identified by him. See the last three paragraphs.

In  1988 in the single month of April, a non-summer month, a high Rainfall of 440mm occurred. Being a non-summer month is rare in itself. It was followed by a similar event in April of 1989 of 564mm. These events were sufficiently large to fill the dams. At that early stage the Dams were full and overflowing.

The last of these two events were seven months before the election.

In retrospect, this very high level may have been sufficient to draw incorrect conclusions against the advice of the Engineers and Hydrologists. This advice must necessarily have been present when the land purchase was proceeding.

This was followed up by the large inflows of 1992, 1996 and 1999 which filled the dams and buried the view of heavy and steady population growth's requirements and the implications of the cancellation of the Wolfdene dam.

Conclusion

The Wolfdene Dam cancellation is central to - entering into and emergence from a rare period of "uncommon events"

We have seen that the cancellation of the Wolfdene dam has denied us the provision of water except on a restricted basis. The decision relates to the entering this rare period of 5 uncommon events in 12 years.

We are now seeing that as we emerge from this period, our current leaders attribute it to a "drought" with all the decisions being made on this basis.

The solution lies in the harnessing of the surpluses from these uncommon events. This web-site provides the solution.