Q5 How fair is it to say its not a natural lake ?

 In my letter to the paper last week,  I should have perhaps put "natural"  in inverted brackets .   As a scientist I find it difficult to know what the commonly used word" natural"  means ( it has philosophical implications too ) because natural processes ( a clearer term)are always adjusting and accommodating to change. I don't accept the common perception that natural means unchanging and final - nature is more about processes and life cycles  than it is  about a static state . Its not sound , for example,  to try and preserve things in a museum as some evidently want to. Natural processes  preserve and protect by seeds and spores and eggs and by adjusting to pressures of change.  Perhaps the most accurate way to describe what we have before us right now  is "not entirely natural" because of the higher water level maintained over the last 30 years at least.

Lunette ( shown in blue) type lake systems are by nature shallow and ephemeral,  and our artificial raising of the water since settlement has meant, that its more like a lake than it would otherwise be.( thankfully no one drained it like they have others )
Some people imagine we can go back in time " to nature",  but I don't think  its that simple or desirable to try and do that . Nature is always changing and life cycles are short in "our lake systems - incl streams and sub surface flows ".  I think its better to ensure that we work with nature not against it ; Better  to move forward than assume we can go back to a time when things were" better".
 
As throughout its history,  the lake forming processes have been a changing and interchanging thing( climate , season , drought, grazing , daming,clearing)
The low lying area around Lake Colac formed when lava flows occurred to the north, west and east and blocked off (filled in old creek channels) the natural drainage to the Barwon River system .
The area became a lake , like so many in this area to the north , in  a very dry period several thousand years ago. The clay floor was exposed during the long summer and blew into the clay lunettes ( shown as blue )