How would you go about turning a salt lake into a fresh water lake?
Say 10 km^2 in area.
What problems, solutions?

Brainstorming ideas.

• Bulldoze the salt off.
• Wait until it evaporates enough so that the water is nearly saturated, then pump it off.
• Wait until it’s near full then sink a layer of plastic to the bottom. When it dries, roll the plastic off.
• Use a floating boom to skim the NaCl crystals off the surface as they form. Then sell it.
• When full of nearly fresh water, plough it to get salt up from the deep bed, let the clay settle then pump the rest off.
• Plough it when dry, then sieve the big lumps of salt out.

How low would the salt concentration have to be in a lake in order for the water to be considered “fresh”?

mollwollfumble said:

How would you go about turning a salt lake into a fresh water lake?
Say 10 km^2 in area.
What problems, solutions?

Brainstorming ideas.

• Bulldoze the salt off.
• Wait until it evaporates enough so that the water is nearly saturated, then pump it off.
• Wait until it’s near full then sink a layer of plastic to the bottom. When it dries, roll the plastic off.
• Use a floating boom to skim the NaCl crystals off the surface as they form. Then sell it.
• When full of nearly fresh water, plough it to get salt up from the deep bed, let the clay settle then pump the rest off.
• Plough it when dry, then sieve the big lumps of salt out.

How low would the salt concentration have to be in a lake in order for the water to be considered “fresh”?

A widely used measure for fresh is less than 0.5 parts per thousand of salt. Seawater typically has 35 ppt.

Don’t we already have enough salt, you want more man

mollwollfumble said:

How would you go about turning a salt lake into a fresh water lake?
Say 10 km^2 in area.
What problems, solutions?

Brainstorming ideas.

• Bulldoze the salt off.
• Wait until it evaporates enough so that the water is nearly saturated, then pump it off.
• Wait until it’s near full then sink a layer of plastic to the bottom. When it dries, roll the plastic off.
• Use a floating boom to skim the NaCl crystals off the surface as they form. Then sell it.
• When full of nearly fresh water, plough it to get salt up from the deep bed, let the clay settle then pump the rest off.
• Plough it when dry, then sieve the big lumps of salt out.

How low would the salt concentration have to be in a lake in order for the water to be considered “fresh”?

• chose a water body that is not super-saturated.

Add lots of fresh water and continuously recycle it through a large reverse osmosis plant to extract all the dissolved material.

mollwollfumble said:

How would you go about turning a salt lake into a fresh water lake?
Say 10 km^2 in area.
What problems, solutions?

Brainstorming ideas.

• Bulldoze the salt off.
• Wait until it evaporates enough so that the water is nearly saturated, then pump it off.
• Wait until it’s near full then sink a layer of plastic to the bottom. When it dries, roll the plastic off.
• Use a floating boom to skim the NaCl crystals off the surface as they form. Then sell it.
• When full of nearly fresh water, plough it to get salt up from the deep bed, let the clay settle then pump the rest off.
• Plough it when dry, then sieve the big lumps of salt out.

How low would the salt concentration have to be in a lake in order for the water to be considered “fresh”?

Less than 2 parts per thousand (ppt) for agriculture, some 16/300 of the strength of seawater.
Less that 0.5 ppt counts as “fresh water”, more than that counts as “brackish”.
Typically 0.1 ppt for drinking water.

Or in terms of Total Dissolved Solids in drinking water (from South Australia)

• less than 600 mg/L is regarded as good quality drinking water.
• 600 to 900 mg/L is regarded as fair quality.
• 900 to 1200 mg/L is regarded as poor quality.
• greater than 1200 mg/L is regarded as unacceptable.

Unless I misunderstand, 1200 mg/L is 1.2 ppt.
So would want to aim for a salt concentration (all salts) in the lake of 1.2 ppt or below.

Michael V said:

mollwollfumble said:

How would you go about turning a salt lake into a fresh water lake?
Say 10 km^2 in area.
What problems, solutions?

Brainstorming ideas.

• Bulldoze the salt off.
• Wait until it evaporates enough so that the water is nearly saturated, then pump it off.
• Wait until it’s near full then sink a layer of plastic to the bottom. When it dries, roll the plastic off.
• Use a floating boom to skim the NaCl crystals off the surface as they form. Then sell it.
• When full of nearly fresh water, plough it to get salt up from the deep bed, let the clay settle then pump the rest off.
• Plough it when dry, then sieve the big lumps of salt out.

How low would the salt concentration have to be in a lake in order for the water to be considered “fresh”?

• chose a water body that is not super-saturated.

Add lots of fresh water and continuously recycle it through a large reverse osmosis plant to extract all the dissolved material.

Good idea.
Reverse osmosis typically has high bypass, eg. 1 litre of salty water becomes 0.9 litre of more salty water and 0.1 litre of fresh water. Is that what you want or the other way around, eg. 0.9 litre of fresh water and 0.1 litre of very highly salted water? The second seems better.

Not sure about lakes but I remember seeing a program, on the ABC I think, about someone reducing the ground water salinity by pumping it into evaporation ponds and recovering the salt for export. I believe the intent was to drop the salt level down deeper which would improve the quality of water accessible by plants. I don’t know how successful this was…

Obv, this would depend on its elevation, relationship to other bodies of water, inflow and evap.

If the lake were at the core of an elevated endorheic basin such as the Bulloo , you would do it by directing more flows into it (diverting more tributaries) and blasting away at some hills on the south side so that water would flow to the MDB.

If it were more like a minor lake with the Eyre Basin, then again you’d direct more flows to it and also build up a levy around it so that it would become a freshwater feeder lake that ultimately fed lake Eyre itself.

However, if it is the basal lake of an endorheic basin, depressed below sea level, such as lake Eyre itself, then you might be shit out of luck. If you were determined to do this as part of some supervillain plan, then you would need to seriously direct enough flows i to the EB such that it fills to the the point that it spills out into the MDB: I think that would be somewhere in south Australia or western Victoria about 150 m abovr sea level. I have not done the maths to see how much new water you’d need to divert in there to overcome evap to that extent. You’d destroy ecosystems, communities, and agriculture, all to satiate your need for this colossal monument…

mollwollfumble said:

Michael V said:

mollwollfumble said:

How would you go about turning a salt lake into a fresh water lake?
Say 10 km^2 in area.
What problems, solutions?

Brainstorming ideas.

• Bulldoze the salt off.
• Wait until it evaporates enough so that the water is nearly saturated, then pump it off.
• Wait until it’s near full then sink a layer of plastic to the bottom. When it dries, roll the plastic off.
• Use a floating boom to skim the NaCl crystals off the surface as they form. Then sell it.
• When full of nearly fresh water, plough it to get salt up from the deep bed, let the clay settle then pump the rest off.
• Plough it when dry, then sieve the big lumps of salt out.

How low would the salt concentration have to be in a lake in order for the water to be considered “fresh”?

• chose a water body that is not super-saturated.

Add lots of fresh water and continuously recycle it through a large reverse osmosis plant to extract all the dissolved material.

Good idea.
Reverse osmosis typically has high bypass, eg. 1 litre of salty water becomes 0.9 litre of more salty water and 0.1 litre of fresh water. Is that what you want or the other way around, eg. 0.9 litre of fresh water and 0.1 litre of very highly salted water? The second seems better.

Maybe reverse osmosis is nit the best way to go. Maybe heating and evaporation instead. Boil off most of the fresh water and have a smaller residual of hypersaline brine. Let’s assume the invention of some solar oven that can do this onlarge enough scale.

Or invent some other process. Cool some grains of sand or iron filings or something else in liquid nitrogen or something like that to get them real cold. Then tip them into a pool of water at almost freezing point.They act as nucleation points and ice instantly form around them. Ice floats up to the surface where it can be scraped off and let into some other pond to melt. The grain of sand or iron filings sink to the bottom and can be recovered and re-used. Might take a bit of energy to do this :)

dv said:

Obv, this would depend on its elevation, relationship to other bodies of water, inflow and evap.

If the lake were at the core of an elevated endorheic basin such as the Bulloo , you would do it by directing more flows into it (diverting more tributaries) and blasting away at some hills on the south side so that water would flow to the MDB.

If it were more like a minor lake with the Eyre Basin, then again you’d direct more flows to it and also build up a levy around it so that it would become a freshwater feeder lake that ultimately fed lake Eyre itself.

However, if it is the basal lake of an endorheic basin, depressed below sea level, such as lake Eyre itself, then you might be shit out of luck. If you were determined to do this as part of some supervillain plan, then you would need to seriously direct enough flows i to the EB such that it fills to the the point that it spills out into the MDB: I think that would be somewhere in south Australia or western Victoria about 150 m abovr sea level. I have not done the maths to see how much new water you’d need to divert in there to overcome evap to that extent. You’d destroy ecosystems, communities, and agriculture, all to satiate your need for this colossal monument…

ou could use one of the many endorheic salt lakes in the Western Australian wheatbelt or goldfields. As long as you have the means and enrgy for mass desalination. Draw salty groundwater from the surrounding agricultural areas, thus lowering their water table and improving the lands subject to dry land salinity. Desalinate that groundwater and use the fresh water as you please. You might even be able to extract some useful minerals from it.

mollwollfumble said:

How would you go about turning a salt lake into a fresh water lake?
Say 10 km^2 in area.

So is it a mm deep or a km, it makes a bit of a difference to the solution set.

mollwollfumble said:

How would you go about turning a salt lake into a fresh water lake?
Say 10 km^2 in area.
What problems, solutions?

Brainstorming ideas.

• Bulldoze the salt off.
• Wait until it evaporates enough so that the water is nearly saturated, then pump it off.
• Wait until it’s near full then sink a layer of plastic to the bottom. When it dries, roll the plastic off.
• Use a floating boom to skim the NaCl crystals off the surface as they form. Then sell it.
• When full of nearly fresh water, plough it to get salt up from the deep bed, let the clay settle then pump the rest off.
• Plough it when dry, then sieve the big lumps of salt out.

How low would the salt concentration have to be in a lake in order for the water to be considered “fresh”?

Sometimes you say the strangest things.

roughbarked said:

mollwollfumble said:

How would you go about turning a salt lake into a fresh water lake?
Say 10 km^2 in area.
What problems, solutions?

Brainstorming ideas.

• Bulldoze the salt off.
• Wait until it evaporates enough so that the water is nearly saturated, then pump it off.
• Wait until it’s near full then sink a layer of plastic to the bottom. When it dries, roll the plastic off.
• Use a floating boom to skim the NaCl crystals off the surface as they form. Then sell it.
• When full of nearly fresh water, plough it to get salt up from the deep bed, let the clay settle then pump the rest off.
• Plough it when dry, then sieve the big lumps of salt out.

How low would the salt concentration have to be in a lake in order for the water to be considered “fresh”?

Sometimes you say the strangest things.

He’s getting a tv show hosted by Bill Cosby “mollwollfumble says the darndest things”

sibeen said:

mollwollfumble said:

How would you go about turning a salt lake into a fresh water lake?
Say 10 km^2 in area.

So is it a mm deep or a km, it makes a bit of a difference to the solution set.

Not my thread, but I declare 4 – 8 m depth to be ideal.

party_pants said:

sibeen said:

mollwollfumble said:

How would you go about turning a salt lake into a fresh water lake?
Say 10 km^2 in area.

So is it a mm deep or a km, it makes a bit of a difference to the solution set.

Not my thread, but I declare 4 – 8 m depth to be ideal.

Why?

roughbarked said:

party_pants said:

sibeen said:

So is it a mm deep or a km, it makes a bit of a difference to the solution set.

Not my thread, but I declare 4 – 8 m depth to be ideal.

Why?

So you can grow plants that need sunlight, so the fish (which you’ve also stocked) have somewhere to hide during the day. Deep enough to go boating. Deep enough so it doesn’t get huge temperature variations during the day.

For most of inland WA the evaporation rate is about 2-3 m per year. You want to have a bit of a buffer so that the place doesn’t evaporate away into nothing in one season and kill all of your fish and plants.

(Yes, I have been thinking about this idea long before Moll started this thread :) )

Saltlakes don’t just happen, there will be a reason and unless you can stop this source, then there is no hope of changing one into a freshwater lake. In WA the most common source is from a limestone or from paleohydrothermal activity.

PermeateFree said:

Saltlakes don’t just happen, there will be a reason and unless you can stop this source, then there is no hope of changing one into a freshwater lake. In WA the most common source is from a limestone or from paleohydrothermal activity.

limestone substrate

PermeateFree said:

Saltlakes don’t just happen, there will be a reason and unless you can stop this source, then there is no hope of changing one into a freshwater lake. In WA the most common source is from a limestone or from paleohydrothermal activity.

There is just so much salt down there and nowhere near enough fresh water to change the situation. We could make Lake Eyre a lot deeper and it would still be salty.

It’s not going to be a fresh water lake unless there are outflows. If you are pouring water in and the only egress is evap, it’s a salt water lake.

There are plenty of examples in the real world of fresh water lakes becoming salt lakes but not many of the reverse, recently. One temporary example was the North Aral Sea. As the Aral Sea was drying up because most of its inflow was diverted for agriculture, there was a spell after the North Aral became separated from the South Aral, and the North Aral started to become more fresh as it became in effect a feeder for the lower lying South Aral. However, now the SA has completely dried and the NA is a basal salt lake with no outflows.

dv said:

It’s not going to be a fresh water lake unless there are outflows. If you are pouring water in and the only egress is evap, it’s a salt water lake.

There are plenty of examples in the real world of fresh water lakes becoming salt lakes but not many of the reverse, recently. One temporary example was the North Aral Sea. As the Aral Sea was drying up because most of its inflow was diverted for agriculture, there was a spell after the North Aral became separated from the South Aral, and the North Aral started to become more fresh as it became in effect a feeder for the lower lying South Aral. However, now the SA has completely dried and the NA is a basal salt lake with no outflows.

Yes but the outflow would need to take up most of the lower MDB.

roughbarked said:

dv said:

It’s not going to be a fresh water lake unless there are outflows. If you are pouring water in and the only egress is evap, it’s a salt water lake.

There are plenty of examples in the real world of fresh water lakes becoming salt lakes but not many of the reverse, recently. One temporary example was the North Aral Sea. As the Aral Sea was drying up because most of its inflow was diverted for agriculture, there was a spell after the North Aral became separated from the South Aral, and the North Aral started to become more fresh as it became in effect a feeder for the lower lying South Aral. However, now the SA has completely dried and the NA is a basal salt lake with no outflows.

Yes but the outflow would need to take up most of the lower MDB.

Mmm.

dv said:

roughbarked said:

dv said:

It’s not going to be a fresh water lake unless there are outflows. If you are pouring water in and the only egress is evap, it’s a salt water lake.

There are plenty of examples in the real world of fresh water lakes becoming salt lakes but not many of the reverse, recently. One temporary example was the North Aral Sea. As the Aral Sea was drying up because most of its inflow was diverted for agriculture, there was a spell after the North Aral became separated from the South Aral, and the North Aral started to become more fresh as it became in effect a feeder for the lower lying South Aral. However, now the SA has completely dried and the NA is a basal salt lake with no outflows.

Yes but the outflow would need to take up most of the lower MDB.

Mmm.

Well, what does the math say?

roughbarked said:

dv said:

roughbarked said:

Yes but the outflow would need to take up most of the lower MDB.

Mmm.

Well, what does the math say?

You really going to nerdsnipe me into working this out?

dv said:

roughbarked said:

dv said:

Mmm.

Well, what does the math say?

You really going to nerdsnipe me into working this out?

No. You already have a fair idea of how much land would have to go under.

> You really going to nerdsnipe me into working this out?

Can I nerdsnipe you into this metric units conversion

Suppose a lake has a catchment area of ~10,000 km² and rainfall of about 100 mm/yr.

What’s that come to in gigalitres per year?

mollwollfumble said:

> You really going to nerdsnipe me into working this out?

Can I nerdsnipe you into this metric units conversion

Suppose a lake has a catchment area of ~10,000 km² and rainfall of about 100 mm/yr.

What’s that come to in gigalitres per year?

Check this. 1 GL of water = 1 mm of rain over an area of 1000 km²

mollwollfumble said:

> You really going to nerdsnipe me into working this out?

Can I nerdsnipe you into this metric units conversion

Suppose a lake has a catchment area of ~10,000 km² and rainfall of about 100 mm/yr.

What’s that come to in gigalitres per year?

1,000

mollwollfumble said:

mollwollfumble said:

> You really going to nerdsnipe me into working this out?

Can I nerdsnipe you into this metric units conversion

Suppose a lake has a catchment area of ~10,000 km² and rainfall of about 100 mm/yr.

What’s that come to in gigalitres per year?

Check this. 1 GL of water = 1 mm of rain over an area of 1000 km²

yes.

The other question I have is why the need for the lake to be fresh water? Maybe brackish water of around 10 ppt might be just as good. Unless you plan to grow something in the lake that is specifically fresh water.

If you were going to use the fresh water for agriculture you’d be better off building massive arrays of storage tanks and forgetting about the lake altogether. A shallow lake being just about the worst configuration for evap oration.

Michael V said:

mollwollfumble said:

mollwollfumble said:

> You really going to nerdsnipe me into working this out?

Can I nerdsnipe you into this metric units conversion

Suppose a lake has a catchment area of ~10,000 km² and rainfall of about 100 mm/yr.

What’s that come to in gigalitres per year?

Check this. 1 GL of water = 1 mm of rain over an area of 1000 km²

yes.

Thanks.

Feeding rainfalls and catchment areas from Idriess scheme.

Rainfall from the Idriess scheme onto the enlarged Lake Eyre + Bulloo River catchment area is 250,000 GL / yr, up by 54%.

Rainfall from the Idriess scheme onto the enlarged Warrego River + Paroo River catchment area is 90,000 GL / yr, up by 90%.

I wasn’t expecting such as massive increase in water. The increase in area of the enlarged Lake Eyre + Bulloo River catchment is only 10%. But this increase in area is in high rainfall districts.

party_pants said:

The other question I have is why the need for the lake to be fresh water? Maybe brackish water of around 10 ppt might be just as good. Unless you plan to grow something in the lake that is specifically fresh water.

If you were going to use the fresh water for agriculture you’d be better off building massive arrays of storage tanks and forgetting about the lake altogether. A shallow lake being just about the worst configuration for evap oration.

Why? For trees and wildlife, such as kangaroos, and any agricultural projects. The salt lakes in Australia are very recent geologically speaking. When aborigines first arrived they would have been almost all fresh water.

mollwollfumble said:

party_pants said:

The other question I have is why the need for the lake to be fresh water? Maybe brackish water of around 10 ppt might be just as good. Unless you plan to grow something in the lake that is specifically fresh water.

If you were going to use the fresh water for agriculture you’d be better off building massive arrays of storage tanks and forgetting about the lake altogether. A shallow lake being just about the worst configuration for evap oration.

Why? For trees and wildlife, such as kangaroos, and any agricultural projects. The salt lakes in Australia are very recent geologically speaking. When aborigines first arrived they would have been almost all fresh water.

No, I mean what is your purpose behind creating this lake? What’s it for?

sibeen said:

mollwollfumble said:

How would you go about turning a salt lake into a fresh water lake?
Say 10 km^2 in area.

So is it a mm deep or a km, it makes a bit of a difference to the solution set.

Yes. It does.

party_pants said:

mollwollfumble said:

party_pants said:

The other question I have is why the need for the lake to be fresh water? Maybe brackish water of around 10 ppt might be just as good. Unless you plan to grow something in the lake that is specifically fresh water.

If you were going to use the fresh water for agriculture you’d be better off building massive arrays of storage tanks and forgetting about the lake altogether. A shallow lake being just about the worst configuration for evap oration.

Why? For trees and wildlife, such as kangaroos, and any agricultural projects. The salt lakes in Australia are very recent geologically speaking. When aborigines first arrived they would have been almost all fresh water.

No, I mean what is your purpose behind creating this lake? What’s it for?

Jet skis.

mollwollfumble said:

party_pants said:

The other question I have is why the need for the lake to be fresh water? Maybe brackish water of around 10 ppt might be just as good. Unless you plan to grow something in the lake that is specifically fresh water.

If you were going to use the fresh water for agriculture you’d be better off building massive arrays of storage tanks and forgetting about the lake altogether. A shallow lake being just about the worst configuration for evap oration.

Why? For trees and wildlife, such as kangaroos, and any agricultural projects. The salt lakes in Australia are very recent geologically speaking. When aborigines first arrived they would have been almost all fresh water.

Just where do you get this enlightenment?

PermeateFree said:

mollwollfumble said:

party_pants said:

The other question I have is why the need for the lake to be fresh water? Maybe brackish water of around 10 ppt might be just as good. Unless you plan to grow something in the lake that is specifically fresh water.

If you were going to use the fresh water for agriculture you’d be better off building massive arrays of storage tanks and forgetting about the lake altogether. A shallow lake being just about the worst configuration for evaporation.

Why? For trees and wildlife, such as kangaroos, and any agricultural projects. The salt lakes in Australia are very recent geologically speaking. When aborigines first arrived they would have been almost all fresh water.

Just where do you get this enlightenment?

From the slogan “Think globally, act locally”.

But in this case from reading about camels getting bogged crossing Lake Amadeus as they fell through the thin crust of salt. Which made me wonder about how thick the crust of salt actually is.

As for “recent geologically speaking”, from the megafauna fossils along the shores of salt lakes.

mollwollfumble said:

PermeateFree said:

mollwollfumble said:

Why? For trees and wildlife, such as kangaroos, and any agricultural projects. The salt lakes in Australia are very recent geologically speaking. When aborigines first arrived they would have been almost all fresh water.

Just where do you get this enlightenment?

From the slogan “Think globally, act locally”.

But in this case from reading about camels getting bogged crossing Lake Amadeus as they fell through the thin crust of salt. Which made me wonder about how thick the crust of salt actually is.

As for “recent geologically speaking”, from the megafauna fossils along the shores of salt lakes.

I have spent a lot of time around saltlakes as often rare plants can be found near them. As I said before a limestone substrate is responsible for many saltlakes as salts leach into them after rain. These limestones particularly far inland were formed when inundated by the sea, which alone would take you back many millions of years. Others come from the a softer limestone substrate leached by the rain from windblown coastal sands that would only be tens of thousands of years, extending back over at least the last two Ice Ages.

Still other saltlakes have been formed by hydrothermal activity when tectonic earth movement has pressurised aquifers forcing saline water to the surface, which probably would have flowed for many years. There are many interesting things about saltlake, most of which are poorly known.

PermeateFree said:

mollwollfumble said:

PermeateFree said:

Just where do you get this enlightenment?

From the slogan “Think globally, act locally”.

But in this case from reading about camels getting bogged crossing Lake Amadeus as they fell through the thin crust of salt. Which made me wonder about how thick the crust of salt actually is.

As for “recent geologically speaking”, from the megafauna fossils along the shores of salt lakes.

I have spent a lot of time around saltlakes as often rare plants can be found near them. As I said before a limestone substrate is responsible for many saltlakes as salts leach into them after rain. These limestones particularly far inland were formed when inundated by the sea, which alone would take you back many millions of years. Others come from the a softer limestone substrate leached by the rain from windblown coastal sands that would only be tens of thousands of years, extending back over at least the last two Ice Ages.

Still other saltlakes have been formed by hydrothermal activity when tectonic earth movement has pressurised aquifers forcing saline water to the surface, which probably would have flowed for many years. There are many interesting things about saltlake, most of which are poorly known.

Tell me more.

party_pants said:

roughbarked said:

party_pants said:

Not my thread, but I declare 4 – 8 m depth to be ideal.

Why?

So you can grow plants that need sunlight, so the fish (which you’ve also stocked) have somewhere to hide during the day. Deep enough to go boating. Deep enough so it doesn’t get huge temperature variations during the day.

For most of inland WA the evaporation rate is about 2-3 m per year. You want to have a bit of a buffer so that the place doesn’t evaporate away into nothing in one season and kill all of your fish and plants.

(Yes, I have been thinking about this idea long before Moll started this thread :) )

Thanks. That makes great sense.

dv said:

Obv, this would depend on its elevation, relationship to other bodies of water, inflow and evap.

If the lake were at the core of an elevated endorheic basin such as the Bulloo , you would do it by directing more flows into it (diverting more tributaries) and blasting away at some hills on the south side so that water would flow to the MDB.

If it were more like a minor lake with the Eyre Basin, then again you’d direct more flows to it and also build up a levy around it so that it would become a freshwater feeder lake that ultimately fed lake Eyre itself.

However, if it is the basal lake of an endorheic basin, depressed below sea level, such as lake Eyre itself, then you might be shit out of luck. If you were determined to do this as part of some supervillain plan, then you would need to seriously direct enough flows i to the EB such that it fills to the the point that it spills out into the MDB: I think that would be somewhere in south Australia or western Victoria about 150 m abovr sea level. I have not done the maths to see how much new water you’d need to divert in there to overcome evap to that extent. You’d destroy ecosystems, communities, and agriculture, all to satiate your need for this colossal monument…

OK, so flush it out rather than truck it out. That’s definitely sensible. Let’s check the math.

A truck (single rather than double) can carry what, say 30 tons of salt.

> Say a lake 10 km^2 in area.

One load would be 3 tons per square km, or a thickness of … at a density of 2.17 ton/m³ is a thickness of … that’s only 1.4 microns thick. Which is way thinner than anything realistic.

So yeah, trucking salt would not be a smart idea. Damn. Have to flush it out.

And trucking brine out would be a much worse option.

Or bury salt? Geosequester it in plastic? 2,170 tons of salt would be a cube 10m * 10m * 10m, that’s a container that is definitely within reach of a bulldozer and the cost of plastic lining isn’t too large. Hmm.

You do know that people have been talking about this since they discovered Lake Eyre in the first place?
There is too much salt and it is never going to flush away because there isn’t enough fresh water and even if there was, it would all evaporate faster than it could be put there.

mollwollfumble said:

PermeateFree said:

mollwollfumble said:

Why? For trees and wildlife, such as kangaroos, and any agricultural projects. The salt lakes in Australia are very recent geologically speaking. When aborigines first arrived they would have been almost all fresh water.

Just where do you get this enlightenment?

From the slogan “Think globally, act locally”.

But in this case from reading about camels getting bogged crossing Lake Amadeus as they fell through the thin crust of salt. Which made me wonder about how thick the crust of salt actually is.

As for “recent geologically speaking”, from the megafauna fossils along the shores of salt lakes.

The thin salt is simply what is deposited on the surface by the last evaporation. It is only ever thin on the surface but unless the trees are put back, you’ll be able to mine salt for hundreds of years and still have a salt problem.

roughbarked said:

mollwollfumble said:

PermeateFree said:

Just where do you get this enlightenment?

From the slogan “Think globally, act locally”.

But in this case from reading about camels getting bogged crossing Lake Amadeus as they fell through the thin crust of salt. Which made me wonder about how thick the crust of salt actually is.

As for “recent geologically speaking”, from the megafauna fossils along the shores of salt lakes.

The thin salt is simply what is deposited on the surface by the last evaporation. It is only ever thin on the surface but unless the trees are put back, you’ll be able to mine salt for hundreds of years and still have a salt problem.

Only ever thin on the surface? Do you mean thousands of separate layers of mud then salt then mud then salt? If so, then that’s a problem.

I’m just starting to realist that about the mining. But that is why I initially suggested to start small.

roughbarked said:

You do know that people have been talking about this since they discovered Lake Eyre in the first place?
There is too much salt and it is never going to flush away because there isn’t enough fresh water and even if there was, it would all evaporate faster than it could be put there.

No I didn’t realise that, suppose I should have. All talk and no action? Is there an archive of the talk somewhere?

mollwollfumble said:

roughbarked said:

mollwollfumble said:

The thin salt is simply what is deposited on the surface by the last evaporation. It is only ever thin on the surface but unless the trees are put back, you’ll be able to mine salt for hundreds of years and still have a salt problem.

Only ever thin on the surface? Do you mean thousands of separate layers of mud then salt then mud then salt? If so, then that’s a problem.

I’m just starting to realist that about the mining. But that is why I initially suggested to start small.

roughbarked said:

You do know that people have been talking about this since they discovered Lake Eyre in the first place?
There is too much salt and it is never going to flush away because there isn’t enough fresh water and even if there was, it would all evaporate faster than it could be put there.

No I didn’t realise that, suppose I should have. All talk and no action? Is there an archive of the talk somewhere?

Have you got Cole’s Funny Picture Book? There is a detailed description of the proposed channel to be cut through central Australia which was all the rage back in the 1880’s.
They even tried some of the plans or parts thereof. The Darling anabranch is one example.

PermeateFree said:

Saltlakes don’t just happen, there will be a reason and unless you can stop this source, then there is no hope of changing one into a freshwater lake. In WA the most common source is from a limestone substrate or from paleohydrothermal activity.

>>So, when we find a limestone, we know that there was a large lake or ocean present at that location in the past. When we find evaporites, we can tell that we were probably in a hot and dry environment such as a desert playa.<<

http://ratw.asu.edu/aboutrocks_chemicalsedimentary.html

PermeateFree said:

PermeateFree said:

Saltlakes don’t just happen, there will be a reason and unless you can stop this source, then there is no hope of changing one into a freshwater lake. In WA the most common source is from a limestone substrate or from paleohydrothermal activity.

>>So, when we find a limestone, we know that there was a large lake or ocean present at that location in the past. When we find evaporites, we can tell that we were probably in a hot and dry environment such as a desert playa.<<

http://ratw.asu.edu/aboutrocks_chemicalsedimentary.html

> Stop the source.

It would have to be on the surface, wouldn’t it, most of the time? One of my CSIRO projects for many years was predicting the transport of wind-blown salt from the coast of Australia into the interior. Globally, the amount of salt that flows into the ocean from the land by rivers matches the amount that blows into the interior from the coast with the wind.

roughbarked said:

Have you got Cole’s Funny Picture Book? There is a detailed description of the proposed channel to be cut through central Australia which was all the rage back in the 1880’s.
They even tried some of the plans or parts thereof. The Darling anabranch is one example.

Thanks for that.

mollwollfumble said:

PermeateFree said:

PermeateFree said:

Saltlakes don’t just happen, there will be a reason and unless you can stop this source, then there is no hope of changing one into a freshwater lake. In WA the most common source is from a limestone substrate or from paleohydrothermal activity.

>>So, when we find a limestone, we know that there was a large lake or ocean present at that location in the past. When we find evaporites, we can tell that we were probably in a hot and dry environment such as a desert playa.<<

http://ratw.asu.edu/aboutrocks_chemicalsedimentary.html

> Stop the source.

It would have to be on the surface, wouldn’t it, most of the time? One of my CSIRO projects for many years was predicting the transport of wind-blown salt from the coast of Australia into the interior. Globally, the amount of salt that flows into the ocean from the land by rivers matches the amount that blows into the interior from the coast with the wind.

roughbarked said:

Have you got Cole’s Funny Picture Book? There is a detailed description of the proposed channel to be cut through central Australia which was all the rage back in the 1880’s.
They even tried some of the plans or parts thereof. The Darling anabranch is one example.

Thanks for that.

When sea-levels drop during an ice age it will also be a dry period that enables strong winds to transport fine sand, shell grit and salt many kilometres inland. Over thousands of year, especially when sea-levels rise and rainfall increases, the salt dissolves and sinks deeper into the soil until it reaches an impervious layer like rock or clay, whilst the shell-grit is leached from the sand to form a soft limestone below. The salts will move up and down depending water-table level and will slowly drain into hollows or other low lying areas to form salt or playa lakes.

PermeateFree said:

mollwollfumble said:

PermeateFree said:

> Stop the source.

It would have to be on the surface, wouldn’t it, most of the time? One of my CSIRO projects for many years was predicting the transport of wind-blown salt from the coast of Australia into the interior. Globally, the amount of salt that flows into the ocean from the land by rivers matches the amount that blows into the interior from the coast with the wind.

roughbarked said:

Have you got Cole’s Funny Picture Book? There is a detailed description of the proposed channel to be cut through central Australia which was all the rage back in the 1880’s.
They even tried some of the plans or parts thereof. The Darling anabranch is one example.

Thanks for that.

When sea-levels drop during an ice age it will also be a dry period that enables strong winds to transport fine sand, shell grit and salt many kilometres inland. Over thousands of year, especially when sea-levels rise and rainfall increases, the salt dissolves and sinks deeper into the soil until it reaches an impervious layer like rock or clay, whilst the shell-grit is leached from the sand to form a soft limestone below. The salts will move up and down depending water-table level and will slowly drain into hollows or other low lying areas to form salt or playa lakes.

Where it stays.
I’ve breathed a lot of dust in my time but none of it tasted like salt.