Concern Over Griffith Determination of Salty Groundwater

In the recent meeting in regard to fitting a one-way valve, Griffith responded in the meeting minutes by stating;

  • The data from the vertical profiler indicated there is a direct link to tidal patterns in both the deeper sections and the upper sections of the lake and the blocking of the exchange pipe would not reduce saltwater inflow due to this direct link.

The diagram below shows the profiler data and the variations in salt levels – Griffith are stating these changes relate to tide levels showing significant groundwater input pushed in by the tides.

Unfortunately these assumptions ARE INCORRECT!

If you break down the data into days you can see that the peaks occur at THE SAME TIME EVERY DAY. See daily lines on diagram.

Tidal patterns advance by approximately 1 hour every day so if these variations were related to tidal variations they would occur at different times of the day but they do not!

The conclusion is that THESE VARIATIONS DO NOT RELATE TO ANY TIDAL PUMPING OR GROUND WATER INTRUSION AND THAT ANY ASSUMPTIONS BASED ON THIS ARE ALSO INCORRECT!

The result is that Griffith have not progressed further and investigated the influence of the canal and ran modelling on the effects.

The result is that the review of the one-way valve by Alluvium has been compromised by not just misleading but incorrect data and assumptions.

The fact that Alluvium highlighted only medium confidence in their review due to no modelling if a further indication of a compromised assessment.

So where is the evidence of significant groundwater?

The Care Group have requested clarification over these important findings and will advise if these observations are correct.

Please see link to minutes of Meeting – Minutes