On the face of it
A close-up of the smiley face Photo: ACTEW Corporation
My eyes glaze over as Steve Ryan, the quality manager of the enlarged Cotter Dam, proudly explains, ‘‘The roller compacted concrete mix is prepared at the twin batch plants over there and then moved via this specialised conveyor belt system down the right-hand abutment. When the wall is complete it will contain over one million tonnes of concrete.’’
Sure it all sounds impressive, but I’m not here to be educated on the ins and outs of slapping together a concrete wall – even if it is going to be the highest of its kind in the country. No, I’ve come to the Cotter for a tour of Canberra’s biggest construction site in the hope of a close-up view of Australia’s biggest rock smiley face.
Steve finally gets the message that I’ve heard more than enough about the dam’s engineering challenges and I convince him to drive me to the secret smiley face which ‘‘he’s heard about...but not seen’’.
Aerial view of fish habitat at enlarged Cotter Dam - can you make out the smiley face (centre and to the right)? Photo: ACTEW Corporation
On the way past the site office he picks up Sarah Wilson, the project’s graduate environmental scientist, and also an aerial photo of the site in which you can clearly see a face smiling up at you from among long lines of rock – a partially completed artificial fish habitat.
‘‘When the dam is complete and the reservoir begins to fill, the macrophyte reed beds that the endangered Macquarie perch currently use as shelter from predators such as diving cormorants will be inundated,’’ explains Sarah. ‘‘Results of a trial showed that in the absence of reed beds, the fish prefer artificial rock reefs over other forms of artificial habitat and as a result there is seven kilometres of rock reef being constructed around the enlarged reservoir.’’
Steve drives as close as he can to where he reckons the smiley face should be. We jump out of his ute and start walking along the intersection of two of the rock reefs.
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‘‘They are being built in continuous lines at various different levels, so no matter the water level in the enlarged dam, there will be habitat for the fish to hide in,’’ says Sarah as we stumble over the first three-metre high by about two-metre wide rocky reef.
But it’s not just a matter of piling the rock up in reefs. It’s almost like the aquatic version of dry stone walling. The rocks themselves have to be a certain size (0.8-1.2 metres) and arranged in such a mazelike way that a fish can easily hide in them. Ever the stats man, the fluro-vested Steve chimes in with ‘‘Once the seven kilometres is complete we expect to have used more than 52 tonnes [of rock].’’
Eventually we reach the smiley face. It’s a good five metres in diameter and while you probably get a better appreciation of it from looking at an aerial photograph, seeing it up close and personal reveals it even has eyebrows and blue nostrils.
Macquarie perch - what will they think of the smiley face? Photo: E Beaton, ACT Government
Now, while the smiley face definitely isn’t part of the rock reef’s approved design, Steve says, ‘‘There are no plans to remove it.’’
As to its origins? ‘‘Most believe that when the contractor responsible for building that particular part of the rock reef had two lines of rock meet, for a bit of a laugh, he put a smiley face in as the intersection point,’’ says Steve. ‘‘No one seems to know who actually did it.’’
I hope it does stay, for not only does it provide a focus on the ingenious work undertaken to protect our native fish species but it also has the potential to become, dare I say it, the ‘‘face’’ of the enlarged dam.
Sarah Wilson takes a rest on the smiley face's nose! Photo: Tim the Yowie Man
Perhaps airlines could adjust their flight paths so that on approach to Canberra they fly directly over the creative rock formation. A giant smiling face – now that would be a much more enticing first impression for visitors to Canberra than seeing the Parliament House flagpole, wouldn’t it?
The only catch might be when the dam fills and the rock reefs, including good old smiley, are completely submerged. To counter this, maybe when Steve and his men have finished with the dam wall they could turn their attention to constructing a 40-metre or so high rock snorkel for smiley? Now, that would be an engineering feat to crow about.
Have you got a suggested nickname for the smiley face? If so, please let me know.