Local concerns
It would appear from the budget announcements that Tillegra Dam is now a foregone conclusion with $33M being allocated this financial year presumably for preliminary investigation and design.
We have all heard that Dungog Shire will benefit from the Dam and I again ask the proponents of the project to descibe what these benefits are and how we as ratepayers will profit by its construction.
Having observed first hand the noise and environmental damaged created by high speed boats, water skiers and surf ski riders in similar water ways I cannot imagine that there will be too many benefits from this type of recreational use of the dam.
Certainly the collection of plastic lunch wraps, cardboard food cartons, plastic bottles and broken glass, emptying rubbish bins, cleaning toilets and BBQ’s may provide a weekly income for someone in the local area. There will also be an opportunity for local residents to adopt a section of road to keep it tidy and perhaps form a Tillegra chapter of the annual Cleanup Australia organisation. This may be the benefits that the proponents have in mind.
On a more serious note there are major concerns being raised by many people in the shire regarding the proposed construction of Tillegra Dam over a known geological fault that has the potential to cause the dam to fail with devastating results. It is considered that this aspect is so important that a mandatory pre condition for the project should be a totally independent, open and transparent investigation by world recognised geological and structural engineering experts to determine if the area is suitable for the such an enormous dam.
In many areas where known geological faults exist (including areas of Sydney) local councils insist on geotechnical investigations before approving construction of a residence and in most cases houses built in fault zones are limited in height to single storey. Tillegra will be the height of a sky scraper and so far it would appear the full extent of the fault and remains unknown.
The risk to such a structure built within a fault zone must be considered extreme particularly as it is required to withstand the pressures of billions of tons of water.
Before construction of the dam is allowed to proceed the safety concerns of downstream residents need to be addressed and there are compelling reasons for the involvement early in the planning stage of SES, Workcover and other agencies to develop with the proponents a comprehensive risk management (disaster) plan well in advance of the dam filling. It is suggested that something more sophisticated than providing those people residing below the dam with air horns to warn people in Dungog of a breach in the dam wall will be required.
There are many other issues that we as residents of the shire and indeed others outside the shire need to understand before this second major dam is constructed in the area including the effects on the following:
(i) property insurance premiums
(ii) property values
(iii) viability of businesses
(iv) long term future of Dungog
(v) health and welfare of those residents living in the knowledge that a breach of the dam wall would mean that everything in the path of the wave front including Dungog Town would be wiped from the face of the earth
The effects of our most recent storm and local flooding would pale into insignificance by comparison to the failure of such a dam wall.
There is no strength in the argument that the dam will regulate the flow of water in the Williams River in the the time of flooding because if the dam is already full (like Chichester was at the time of the latest storm) then water will flow over the spill way unchecked with the same result as occured a couple of weeks ago. For the five or so years that the dam takes to fill the Williams will be deprived of water, all the tributaries will be sucked dry with the strong likelihood of increased salination below Seaham.
The establishment of a so called Tillegra Dam Consultative Group has deliberately ignored the impact of this dam on the wider community and perhaps should be disbanded and a new group formed that is truly representative of all people affected by its construction and presence including those from other shires.
Geoff Berry
Wallarobba
Letter to Editor Dungog Chronicle 27 June 2007