Great Lake

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Great Lake

Postby tasadam » Wed 12 Jan, 2011 7:25 am

Driving back from Hobart on Sunday, I noticed that the area of land between the "old" normal water mark at Great Lake and the current low level, has been so low for so long that vegetation is taking a good hold.
Wondering roughly how much rain would be needed to restore the lake to close to capacity.
I have a suspicion that since Basslink was installed, it is in the interests of those in control to take what they can from it to make power to sell to Victoria, but it sure would be nice to see this lake full again.
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Re: Great Lake

Postby ILUVSWTAS » Wed 12 Jan, 2011 12:42 pm

tasadam wrote:Wondering roughly how much rain would be needed to restore the lake to close to capacity.




Somewhere around QLD levels would probably do it.
Nothing to see here.
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Re: Great Lake

Postby sthughes » Fri 14 Jan, 2011 12:43 pm

tasadam wrote: sure would be nice to see this lake full again.

Indeed, but not again - it would be a first! :D


tasadam wrote:Wondering roughly how much rain would be needed to restore the lake to close to capacity.

Well it seems to be about 3.6 million cubic metres in capacity (including Arthurs) (or is that just above its original natural level?), and is about 33% full. So that means we need about 2.4 million cubic metres to fill it. Now the catchment is quite small so to achieve that I'd guesstimate (after a quick quesstimate of catchment area of 100,000ha) we need about 250mm of rain over the entire catchment (and for it all to run off and none be used). Doesn't seem like much, just shut it off for 3 months over winter. I suspect perhaps my info is wrong! Still it kept me busy for a few minutes. :wink:

Last time I drove through the lake was looking great at it's current level. Much better than the 15% or so a few years back when driving past on a hot windy day there appeared to be dust storms around the bank where there are (were) no plants!
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Re: Great Lake

Postby BarryJ » Fri 14 Jan, 2011 2:19 pm

tasadam wrote:Driving back from Hobart on Sunday, I noticed that the area of land between the "old" normal water mark at Great Lake and the current low level, has been so low for so long that vegetation is taking a good hold.
Wondering roughly how much rain would be needed to restore the lake to close to capacity.
I have a suspicion that since Basslink was installed, it is in the interests of those in control to take what they can from it to make power to sell to Victoria, but it sure would be nice to see this lake full again.

Since the dam height was increased to it's current level, Great Lake has NEVER been full. The highest it has been is 5m or so below full. It is currently 12.9m below full but 18 months or so ago, it was down around 17-17.7m below full.
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