Author : J. V. Hodgkinson F. C. A. Chartered
Accountant : Aug 2006 to November 2013
The principal thrust of this
This is my review based on official
statistics and documents. It is done in conjunction with Ron McMah, grazier
of Imbil and Trevor Herse, retired of the Gold Coast
May 2009 : These calculations were carried out on the basis of "business as usual". Restriction on water use and conservation of water has altered the balance. The four small "uncommon events" that missed their mark in the catchments but still filled the dams by 49% on their own have consolidated this statement which appears as the last paragraph in this section.
"There will be no reserves to counteract real droughts until Uncommon events again occur at some time in the future and are successfully managed."
Calculation of shortfall of our normal requirements without water restrictions
This calculation is relatively straight forward.
The Capacity of the Wivenhoe and Somerset are known and over a period of 6 years with 365 days per year the shortfall is 480ML per day.
After adjustments for water restrictions in 2006 and minor rainfall adjustments, the "business as usual" requirement from these two Dams is 522ML per day.
Rainfall provided 481ML per day to make up the overall requirement of 1003ML per day. This is calculated in "Requirements" button.
The title of these projects is listed on the Water Commission's web-site as " Water Supply Emergency Projects" together with the date of the updated assessment.
As a starting point I have attached my assessment of new water as at April 2007. It shows a new water total of 372ML per day. This assessment includes recycled water and excludes the water being redirected from current Dams and Weirs and in particular the Southern Regional water pipeline.
Shortfall to achieve normal status
The above requirements show a shortfall of 522ML per day. The water grid at present summaries as 372ML per day. The balance not met is 150ML per day.
The delayed projects are now dealt with.
The Depart of Natural Resources fact sheet of March 2006 is examined. I understand that since this issue the Dam size had been reduced with the water pumped when available into the grid system. As it is the same water, the fact sheet is useful.
The sheet advises that it would be prudent to have the Dam completed as early as 2015 with commencement around 2010.
The areas to be supplied are the Beaudesert Shire, Logan City and the Gold Coast. The Gold Coast may not be in this study.
The Dam capacity when full was to be 104,000ML. The inflow into a Dam of that size would be around one third which gives it a provision of 94ML per day. However, the Noosa Shire Council submission to the Senate Committee suggests 14,000ML or 38ML per day. This would apply from year 2015 unless otherwise revised. The fact sheet is missing this essential fact.
Proposed Traveston Dam
The Traveston Dam on the water grid appears to service the North Pine area. This area has been excluded from our requirements calculation as I am dealing with the Wivenhoe/Somerset Dams system.
You will see that over extended periods of many years, the Wivenhoe will be basically empty. We have seen that in the current period where, with normal summer rains and no uncommon events, the Wivenhoe/Somerset system has been drained. The proximity of the Mary Valley catchment to the head waters of both the Brisbane and Stanley rivers is an item of considerable interest from the point of view of harnessing surplus waters from uncommon events.
There are a number of minor projects that will alleviate some of the problem. In so doing some create hardship in the areas concerned. Of special interest to me is increased output from Stradbroke Island. It will require close monitoring to ensure that the ecological balance is not disturbed. I understand this has been reconsidered.
The Lord Mayor of Brisbane has recognized that the rainwater tanks had to be linked into the systems to be effective in requirement reduction.
It is obvious from the above that the absence of "purified" recycled water would leave the Water Grid totally inadequate. A very successful PR campaign was mounted and the public convinced to a point where the vote was cancelled.
What is of interest is the comments on rainfall that accompanied the press release on "no vote". It is dealt with in "Rain 2001-2006" button which includes the actual monthly rainfall of both Dams and you can judge the accuracy of those comments.
In essence, the new water in the "Grid" excluding the proposed Traveston Dam will make up the shortfall between normal Summer rainfall and our requirements. There is no provision for increased requirements of our population growth until the Mary Valley question is settled. It will be either the Traveston Dam proposal or the expanded Borumba Dam to harvest the surpluses from uncommon events. At this point our Leaders have no regard for the Borumba proposal and their PR machine is working overtime on the Traveston site. Both of these proposals are considered elsewhere in this web-site.
There will be no reserves to counteract real droughts until Uncommon events again occur at some time in the future and are successfully managed.