What KAEP said...
Piping or channelling water from the top to the bottom of Australia has certain engineering challenges that cannot be overcome with wishful thinking: silt, evaporation and energy being the toughest ones. I think all detailed analysis has come to the "way, way too expensive" conclusion...though maybe not for this specific version: (devil is in the details!)
I'd love to see an analysis of the ocean pipe to Lake Eyre...an inland sea would change things quite a bit! I wonder if tidal flows could be used to "ream" the pipe/tunnel until it became a channel.
How deep and large would the inland sea be? (will check Sea Level contour for interest.)
Terra-forming dreams are such fun!

Hi Ozandy, yes - don’t believe the knockers or the advocates; just a few checks will suffice to bring you onto one side or the other.
Sea-level contour is indeed a good place to start. Some other essentials are:
what area does that cover for the lake; what annual evaporation rate holds sway for that area; what annual rainfall for it; what is the concentration of salt in sea water; what volume of sea water is needed annually to maintain the lake. And give a thought to rate of increasing salinity.

Having done those checks, and come to a decision after just a modicum of thought and simple calculation - consider that it has been put forward as a practical component of the whole scheme.

I was expecting one or 2 posts from knockers, who would site some 5mm long invertebrate in the bed of these rivers that might be harmed.

Hell, I was way off. We've got knockers coming out of the woodwork, with even less real reason.

I reckon those who brought the idea of the Snowy project to us would probably lynched, if they were around today. We really can't stand anyone with a real vision, rather than a yen for a trip back to the caveman society.

I won't be around to see it, but I wonder what the Chinese will do with the place, after the take over. I reckon with a bit of intelligent engineering, they will get the place to support 100 million quite quickly, then export enough food for another 100 or so million soon after that.

Hi colinsett. Do you know of any such proposals that have had that sort of analysis done?
Filling Lake Eyre using tropical rainwater *appears* to be non-viable due to details, but what about KAEP's ocean pipe from Port Augusta?
An inland sea seems to be more viable than a "fresh" Lake Eyre...but I'd like to see the models and the numbers.
All evaporation losses will be replaced provided the flow rate from the ocean is sufficient (evaporation powered hydro?)...but would it clog, would the inland sea salt up and become a dead foul smelling bog? Would it foul the aquifers...or improve them. An inland sea would certainly change local weather, but how?
Smart to be pretty careful messing with nature on this scale!

Ozandy, I had hoped that you and others would have done the checks independently - I have no expertise. However, there are a few items which are hard to sidestep:
what is regarded as the shoreline of Lake Eyre is about 9 metres below sea-level. That has been estimated to cover 6,500 square kilometers.
Average annual evaporation there is 3.2 metres; annual rainfall less than 0.2metres.
As a result, average annual evaporation would take 6,500X3 divided by 1000; i.e., roughly 20 cubic kilometers of (desalinated) water.
Salt concentration in seawater is very roughly 3 per cent. As a result, somewhere near 20X3 divided by 1000 cubic kilometers of salt (at approx. 2 tonnes/cubic metre) would be added, on average, annually to the lake.
That is for a lake at contour level minus-nine. Drainage pipes are considered to be in danger of silting up if the gradient is less than 1:100. For a Lake Eyre seawater pipe, the gradient (to -9 contour over a 400 km distance) would be 9:400 (about 1:450). I will leave it to the advocacy experts to estimate what size pipe, and circumstances, would be needed to supply the 20 cubic kilometers of water needed each year

Sorry colinset...limited time at work. Debugging makes my brain soggy.
Nice preliminary model, but why assume -9M level when it could go all the way to 0? Vastly more evaporation, but also more depth/volume and constantly renewed from the ocean pipe which is (presumably) less likely to silt than a river/canal. I assumed it would fill until "full" at sea level.
With salt going in and not going out it could end up very salty...but then again the local precipitation would change so all bets are off.
The real questions: Why? Who pays for it? What if it goes bad?
Nature does experimental stuff all the time, but engineers can be sued!