Sunday, October 5, 2008

Beach scapes - old and new

This post presents several photos of the Days Bay beach from 1987/8 and also 2008 - approximately 20 years apart. This is a very short time frame for looking at beach erosion and replenishment. However, one of the interesting things is the relative lack of sand on the Days Bay beach 21 years ago and it illustrates how the sand comes and goes.

The photo below was taken in 1987
This photo was taken October 2008
The photo below was taken 1987, before the EBC
undertook remedial work.

This photo was taken a year later - 1988, after the EBC
had done sand replenishment and Pingau planting.The Council also extended the storm water pipe
seawards
by one length of pipe as it was thought the
stream outflow
was also contributing towards erosion.
Note the height of the sand where the pipe
leaves the bank. Photo 1988
The next photos were taken at the beginning of October
2008
. The top photo is of the new 'replacement' wall.
The extra length of pipe placed in 1988 has been removed.



It is possible that the presence of more shingle on the Days Bay beach today is simply a removal of sand exposing older gravelly material rather than new deposits brought into the harbour by the action of the southerly storms. This is given some weight when one looks closely at the colour and type of coarse material showing up. It has considerably more brown coloured material than the hard grey rock being brought in to the harbour from the south.

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