Even if we could afford the pumping and piping costs, the extra water would only last a few hours at this time of year . While the lake remains a permanently large open water body, its evaporation volumes will be huge . Drying out is part of its life cycle
The 50 or so megalitres a day ( The daily volume out of Geelong area) would only add a few centimetres a month and cost a fortune to get here .
Pipes alone would have to be at least 750 mm diameter( some would argue less, but the friction would be higher ) with multistage pumping and very high risks of failure because of the huge energy and heads involved .
Even at 20 cents per KW, the pumping cost alone would be over a million dollars a year.
Total yearly evaporation from the lakes surface is at least 1300mm We don't notice the lake dropping because our 700 plus rainfall comes over a wide part of the year (like this year ) and we do get some runoff . The runoff is not nearly as much as we used to get-- see previous posts where the permanently changed character of the catchment runoff capability is described.
To raise a cubic metre of water( one tonne ) up one metre takes,in theory a kilowatt of power .In practice any pump will use more than that to do it
Lake Colac is 115 metres above sea level.
We have a wonderful but very large lake, but it remains an unpredictable unreliable and changing deathtrap while we try to maintain its height across all sectors, all of the time. Its water is so rich that it will grow anything in it, in the brief moments when the wind stops.
Vote at your local corner store to get Vicroads to , at the very least, investigate properly the cost of earthworks that would work to save and improve the Lake . Maybe you have questions. List them below
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