Posted by: maximos62 | March 1, 2010

#Coogee the #Avoca of its day: the Destruction of Australia’s Coastal Zone

Growing up in Coogee has left me with a life long interest in the sea. My grandfather was a man who was fascinated by the sea.  Walking along Coogee’s coastline he taught me to see the beauty in sea and shore.

Coogee was the Avoca of it’s day.  A beautiful stretch of coastline, of sandstone cliffs and fixed dunes of pleistocene sands covered by coastal heath.  Once a way through the Lachlan swamps was found and regular steal tram connections established, it attracted great interest from domestic tourists.

Coogee Beach from the north. Both the famous dome and a steam tram are visible

Sheltered by Wedding Cake island from the large Tasman swells, Coogee was the ideal late Victorian  coastal playground.   Soon plans were established to improve the beach areas for tourists. Coogees subdued sheltered surf, sitting in the lee of Wedding Cake Island.

Coogee’s benign waters were to be improved with the construction of a pleasure pier, much like the famous pier in Brighton, back in England, and a shark net top enclose the southern half of the beach.  Mt mother often spoke of these times.  She was six when the pier was opened.

Coogee's pleasure pier, some time in the early 1930s

One of the earlier examples of inappropriate coastal development, the forces of nature dealt with the problem. The pier was extensively damaged in heavy seas during 1934.  Even the calm waters of Sydney could turn on a decent swell. I still remember, as a boy in the 1950s and 1960s, when there was a heavy storm and the sand was shifted out to sea, the foundations of the old pier were sometimes uncovered.

The Central Coast
When my family moved to the Central Coast, just north of Sydney, I came to know another stretch of coastline. My brothers surfed the beaches from Broken Bay to The Entrance, their sons and daughters also carried on the interest.  My son and daughter in-law joined Avoca surf club sustaining the tradition and their children have followed.  None of this is particularly surprising amongst east coast Australian families, many have an intense interest in the sea.  Conversation about the sea is common and knowledge of the sea widespread, so too is knowledge of it’s processes, of powerful forces of erosion and deposition, of rips, reefs, rivers of sand and swells.  So when my son sent me this link to a YouTube video this afternoon, I realised that it could be about many things.  Watching the video alarmed so now I’m burrowing more deeply into the issues that the video raises.

I know little of HMAS Adelaide but I’m surprised that it’s to be sunk off Avoca as a diving attraction.

Having a father who was a marine engineer meant that as a child I made many visits to the hot noisy engine rooms of ships. I still recall these strange places, full of vibrations, odours and pipes bound with asbestos bandages. Engine rooms weren’t healthy places, but of course conditions have improved and I’m sure any hazards have long been dealt with in the Adelaide. From a toxicological I’ve no objection to old ships being sunk as diving attractions provided they pass all appropriate envirionmental tests but what I am concerned about in this case is just where the wreck is to be sunk and precisely how it’s likely impact on the marine environment has been assessed.

So far I’ve looked briefly at a Report on Seismic and Sidescan Sonar Investigation Scuttling of Ex- HMAS Adelaide Avoca, NSW. This report has a map showing the approximate scuttling location.  The first thing I notioce is that the ocean bed material here is fine to medium gloden sand with varying shell content.  Beaches aren’t merely the sand we see when we walk along them, they are dynamic systems an interaction between sand winde and watwer.  These golden sands that lie on the bottom are part of the dynamic beach system, in other words, part of the sand reservoir for Avoca beach. The sand reservior must be free to flow.  The modelling that I see in the report is a snap shot that relies on sand waves as indicators of sand movement.  Any serious testing of coastal processes requires a more dynamic approach. While the study models what it claims to be the impact on waves, it has little to say about sand movement, about the impact of the scuttling on beach erosion and replenishment.

It seems that more active observation is required. The report does have an Addendum, necessary because of concerns raised by Avoca Beach board riders.  This does focus on waves but not the total hydrological system in operation. A more dynamic approach is needed.

I can’t claim to be an expert on coastal morphology, certainly it’s a discipline that I teach to secondary students and something I’ve studied at a tertiary level, but I’m not a scientist and don’t have the tools to conduct anything more than a critical read of the environmental impact materials published on line. Although not an expert I’m conscious of the need to ask questions and also conscious of just how knowledge of coastal processes has spread in the Australian community, through experience. Surfers in particular, often have an intimate knowledge of coastal processes.  It was the comments of a surfer in the video about the scuttling of HMAS Adelaide that caught my attention. What she says rings true.  There are too many questions unanswered for me.

I call upon the NSW Government stop the scuttling.  I’m not confident that appropriate dynamic modeling has been conducted.  Let’s slow down, the last thing we need is another environmental mess.


Responses

  1. I think you have hit the nail on the head. I think most people are happy with the idea of a ship being scuttled to make a dive site. We are all confident that the necessary precautions have been taken to remove PCBs, toxic heavy metals and other environmetal nasties.

    I think what everyone is most concerned about is the scuttling location only 1.7km off Avoca Beach in a water depth of only 32m. Until late last year we were all being told that the site would be off Terrigal, then suddenly the location changed to be off Avoca. Most locals feel that there has been an inadequate investigation of the likely impact of the wreck on waves and the movement of sand on the sea floor.

    There is a public meeting on Saturday 6th of March at 10am at Avoca Shark Tower to discuss the matter further. But with a planned scuttling date on 27th March, time is running out to get a more thorough investigation conducted.

    • I’m glad there’s a meeting. I’ll try and get to it.

  2. […] public and as case in point we’ve had several matters in the news quite recently, namely the plans to sink exHMAS Adelaide off Avoca, addressed elsewhere in this blog and the grounding of the Shen Neng 1 […]


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Categories

%d bloggers like this: