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Tuesday, March 14, 2006

The Kangaloon Aquifer - The SCA's pamphlet

Here is a link to a pamphlet about the Kangaloon Aquifer, which the SCA was handing out at the Robertson Show on Saturday. This document is extremely vague in its assertions on two critical issues: The age of the groundwater, and whether it is linked to the groundwater that feeds the springs in Robertson and the Kangaloon Range, and other basalt hills in the Southern Highlands.

Is this a separate resource to others in the
Southern Highlands?
The high volumes of available groundwater and very low salinity suggest that the groundwater resource in the Upper Nepean sandstones is separate to the other areas to the south, south west and west of Kangaloon.

Hmmm, “Interesting”. The salinity issue is related to the presence of the Wianamatta Shale in the region, for (apparently) if there is leakage of groundwater through the shale layer, it can increase salinity in the Aquifer. (So I have read elsewhere in the SCA website.) But I am puzzled by the reference to high volumes indicating that the Kangaloon Aquifer is not related to the basalt-based springs in the Robertson and Kangaloon hills. After all, we are in the highest rainfall area in the State.

Will my springs and bores be affected?
Most groundwater users in the area access springs for their water. Springs occur in the higher basalt areas of the catchment and are not connected to groundwater in the sandstone. They will therefore not be affected by SCA
production bores and borefield pumping.

Hang on! In half a page, they have moved from claiming that indications suggest that the groundwater resource … is separate …to “Springs occur in the higher basalt areas of the catchment and are not connected to groundwater in the sandstone.”

A categorical statement, to support their proposal, without a scrap of evidence! Worse, it is contradicted by earlier Government studies.

It is my understanding that the basalt rocks which form the hills of Robertson and Kangaloon and many of the typical green hills of the Southern Highlands, were extruded up (in a volcanic process) through the older Sandstone layers (which one sees on the escarpment), and through the Wianamatta Shale layer. The basalt is heavily fractured rock, and so it is permeable, allowing water which falls as rain in the local area to seep down through the basalt, through the shale and into the sandstone layers.

I am not a geologist, but in April 1998, the (then) Dept of Land and Water Conservation produced a paper: “Aquifer Risk Assessment Report”. On P6, there is a table “Sydney South Coast Region”. Within that table there is a category “Medium Risk Aquifers”. It lists:

Southern Highlands Fractured Rock (aquifer) (approx. Wingecarribee Shire LGA boundary).

I am more persuaded by the DLWC scientific assessment of all of the aquifers in NSW than the self-serving propaganda put out by the SCA, to justify a political decision by the Government of the day to drain the Kangaloon Aquifer, and in so doing, let itself off the hook with the proposed Desalination Plant at Kurnell.

More about the age of the groundwater later.


Anonymous said...

Hi, Just to add to this groundwater saving sydney idea. We live on the other side west of you, HighRange and have recieved a letter from Department of Natural Resources (DNR) simply asking for our permission for Water testing our bore that is used for domestic use. Our water is very drinkable but should we be worried that they are gathering information for the SCA or Sydney Catchment Authority, so they can find more locations for more bores to water Sydney. We will recieve a water quality report free of charge. They state that it is not related to the SCA's investigation of groundwater.
Who do you trust?

Denis Wilson said...

Glad you found my site. We all share the same problem - as you said: "who do you trust?".

Frankly, these aquifer issues affect districts and regions, not just individual properties. So, if they are "looking for water", they will find it somewhere or other. I would be inclined to tell them they may proceed a little further, but meanwhile ask as many questions as you can, about what they are doing, why, who has commissioned whatever study they are conducting, (preferably a writtten explanation). Also, tell them you want a written report of their findings, etc.

You could also ring Peta Seaton's office, to ask her advice, (I assume you are within her electorate, but I am not absolutely sure) and to see if she is aware of any water studies being conducted in your area, etc. As you will have seen from other blog entries, Peta Seaton has been involved in the Kangaloon Aquifer issue. Her Electorate Officer is very helpful.